Merge branch 'main' into LYN-1767-AB

Code/Framework/AzCore/AzCore/IO/SystemFile.cpp

@@ -30,7 +30,7 @@ namespace Platform
 
     using FileHandleType = SystemFile::FileHandleType;
 
-    void Seek(FileHandleType handle, const SystemFile* systemFile, SizeType offset, SystemFile::SeekMode mode);
+    void Seek(FileHandleType handle, const SystemFile* systemFile, SystemFile::SeekSizeType offset, SystemFile::SeekMode mode);
     SystemFile::SizeType Tell(FileHandleType handle, const SystemFile* systemFile);
     bool Eof(FileHandleType handle, const SystemFile* systemFile);
     AZ::u64 ModificationTime(FileHandleType handle, const SystemFile* systemFile);
@@ -68,9 +68,8 @@ void SystemFile::CreatePath(const char* fileName)
 }
 
 SystemFile::SystemFile()
+    : m_handle{ AZ_TRAIT_SYSTEMFILE_INVALID_HANDLE }
 {
-    m_fileName[0] = '\0';
-    m_handle = AZ_TRAIT_SYSTEMFILE_INVALID_HANDLE;
 }
 
 SystemFile::~SystemFile()
@@ -81,6 +80,25 @@ SystemFile::~SystemFile()
     }
 }
 
+SystemFile::SystemFile(SystemFile&& other)
+    : SystemFile{}
+{
+    AZStd::swap(m_fileName, other.m_fileName);
+    AZStd::swap(m_handle, other.m_handle);
+}
+
+SystemFile& SystemFile::operator=(SystemFile&& other)
+{
+    // Close the current file and take over the SystemFile handle and filename
+    Close();
+    m_fileName = AZStd::move(other.m_fileName);
+    m_handle = AZStd::move(other.m_handle);
+    other.m_fileName = {};
+    other.m_handle = AZ_TRAIT_SYSTEMFILE_INVALID_HANDLE;
+
+    return *this;
+}
+
 bool SystemFile::Open(const char* fileName, int mode, int platformFlags)
 {
     AZ_PROFILE_INTERVAL_SCOPED(AZ::Debug::ProfileCategory::AzCore, this, "SystemFile::Open - %s", fileName);
@@ -88,42 +106,42 @@ bool SystemFile::Open(const char* fileName, int mode, int platformFlags)
 
     if (fileName)       // If we reopen the file we are allowed to have NULL file name
     {
-        if (strlen(fileName) > AZ_ARRAY_SIZE(m_fileName) - 1)
+        if (strlen(fileName) > m_fileName.max_size())
         {
             EBUS_EVENT(FileIOEventBus, OnError, this, nullptr, 0);
             return false;
         }
 
         // store the filename
-        azsnprintf(m_fileName, AZ_ARRAY_SIZE(m_fileName), "%s", fileName);
+        m_fileName = fileName;
     }
 
     if (FileIOBus::HasHandlers())
     {
         bool isOpen = false;
         bool isHandled = false;
-        EBUS_EVENT_RESULT(isHandled, FileIOBus, OnOpen, *this, m_fileName, mode, platformFlags, isOpen);
+        EBUS_EVENT_RESULT(isHandled, FileIOBus, OnOpen, *this, m_fileName.c_str(), mode, platformFlags, isOpen);
         if (isHandled)
         {
             return isOpen;
         }
     }
 
-    AZ_Assert(!IsOpen(), "This file (%s) is already open!", m_fileName);
+    AZ_Assert(!IsOpen(), "This file (%s) is already open!", m_fileName.c_str());
 
     return PlatformOpen(mode, platformFlags);
 }
 
 bool SystemFile::ReOpen(int mode, int platformFlags)
 {
-    AZ_Assert(strlen(m_fileName) > 0, "Missing filename. You must call open first!");
+    AZ_Assert(!m_fileName.empty(), "Missing filename. You must call open first!");
     return Open(0, mode, platformFlags);
 }
 
 void SystemFile::Close()
 {
-    AZ_PROFILE_INTERVAL_SCOPED(AZ::Debug::ProfileCategory::AzCore, this, "SystemFile::Close - %s", m_fileName);
-    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Close - %s", m_fileName);
+    AZ_PROFILE_INTERVAL_SCOPED(AZ::Debug::ProfileCategory::AzCore, this, "SystemFile::Close - %s", m_fileName.c_str());
+    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Close - %s", m_fileName.c_str());
 
     if (FileIOBus::HasHandlers())
     {
@@ -138,9 +156,9 @@ void SystemFile::Close()
     PlatformClose();
 }
 
-void SystemFile::Seek(SizeType offset, SeekMode mode)
+void SystemFile::Seek(SeekSizeType offset, SeekMode mode)
 {
-    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Seek - %s:%i", m_fileName, offset);
+    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Seek - %s:%i", m_fileName.c_str(), offset);
 
     if (FileIOBus::HasHandlers())
     {
@@ -167,15 +185,15 @@ bool SystemFile::Eof()
 
 AZ::u64 SystemFile::ModificationTime()
 {
-    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::ModTime - %s", m_fileName);
+    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::ModTime - %s", m_fileName.c_str());
 
     return Platform::ModificationTime(m_handle, this);
 }
 
 SystemFile::SizeType SystemFile::Read(SizeType byteSize, void* buffer)
 {
-    AZ_PROFILE_INTERVAL_SCOPED(AZ::Debug::ProfileCategory::AzCore, this, "SystemFile::Read - %s:%i", m_fileName, byteSize);
-    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Read - %s:%i", m_fileName, byteSize);
+    AZ_PROFILE_INTERVAL_SCOPED(AZ::Debug::ProfileCategory::AzCore, this, "SystemFile::Read - %s:%i", m_fileName.c_str(), byteSize);
+    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Read - %s:%i", m_fileName.c_str(), byteSize);
 
     if (FileIOBus::HasHandlers())
     {
@@ -193,8 +211,8 @@ SystemFile::SizeType SystemFile::Read(SizeType byteSize, void* buffer)
 
 SystemFile::SizeType SystemFile::Write(const void* buffer, SizeType byteSize)
 {
-    AZ_PROFILE_INTERVAL_SCOPED(AZ::Debug::ProfileCategory::AzCore, this, "SystemFile::Write - %s:%i", m_fileName, byteSize);
-    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Write - %s:%i", m_fileName, byteSize);
+    AZ_PROFILE_INTERVAL_SCOPED(AZ::Debug::ProfileCategory::AzCore, this, "SystemFile::Write - %s:%i", m_fileName.c_str(), byteSize);
+    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Write - %s:%i", m_fileName.c_str(), byteSize);
 
     if (FileIOBus::HasHandlers())
     {
@@ -212,14 +230,14 @@ SystemFile::SizeType SystemFile::Write(const void* buffer, SizeType byteSize)
 
 void SystemFile::Flush()
 {
-    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Flush - %s", m_fileName);
+    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Flush - %s", m_fileName.c_str());
 
     Platform::Flush(m_handle, this);
 }
 
 SystemFile::SizeType SystemFile::Length() const
 {
-    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Length - %s", m_fileName);
+    AZ_PROFILE_SCOPE_STALL_DYNAMIC(AZ::Debug::ProfileCategory::AzCore, "SystemFile::Length - %s", m_fileName.c_str());
 
     return Platform::Length(m_handle, this);
 }
@@ -379,9 +397,9 @@ namespace
     HasPosixEnumOption(PermissionModeFlags::Write);
 
 #undef HasPosixEnumOption
-}                      
+}
+
 
-                       
 FileDescriptorRedirector::FileDescriptorRedirector(int sourceFileDescriptor)
     : m_sourceFileDescriptor(sourceFileDescriptor)
 {

Code/Framework/AzCore/AzCore/IO/SystemFile.h

@@ -12,10 +12,11 @@
 #pragma once
 
 #include <AzCore/base.h>
-#include <AzCore/std/function/function_fwd.h>
-#include <AzCore/std/string/string.h>
 
+#include <AzCore/IO/Path/Path_fwd.h>
 #include <AzCore/IO/SystemFile_Platform.h>
+#include <AzCore/std/function/function_fwd.h>
+#include <AzCore/std/string/fixed_string.h>
 
 // Establish a consistent size that works across platforms. It's actually larger than this
 // on platforms we support, but this is a good least common denominator
@@ -51,11 +52,15 @@ namespace AZ
             };
 
             using SizeType = AZ::IO::Internal::SizeType;
+            using SeekSizeType = AZ::IO::Internal::SeekSizeType;
             using FileHandleType = AZ::IO::Internal::FileHandleType;
 
             SystemFile();
             ~SystemFile();
 
+            SystemFile(SystemFile&&);
+            SystemFile& operator=(SystemFile&&);
+
             /**
              * Opens a file.
              * \param fileName full file name including path
@@ -69,7 +74,7 @@ namespace AZ
             /// Closes a file, if file already close it has no effect.
             void Close();
             /// Seek in current file.
-            void Seek(SizeType offset, SeekMode mode);
+            void Seek(SeekSizeType offset, SeekMode mode);
             /// Get the cursor position in the current file.
             SizeType Tell();
             /// Is the cursor at the end of the file?
@@ -87,7 +92,7 @@ namespace AZ
             /// Return disc offset if possible, otherwise 0
             SizeType DiskOffset() const;
             /// Return file name or NULL if file is not open.
-            AZ_FORCE_INLINE const char* Name() const    { return m_fileName; }
+            AZ_FORCE_INLINE const char* Name() const    { return m_fileName.c_str(); }
             bool IsOpen() const;
 
             /// Return native handle to the file.
@@ -124,12 +129,12 @@ namespace AZ
 
         private:
             static void CreatePath(const char * fileName);
-            
+
             bool PlatformOpen(int mode, int platformFlags);
             void PlatformClose();
-            
-            FileHandleType  m_handle;
-            char            m_fileName[AZ_MAX_PATH_LEN];
+
+            FileHandleType m_handle;
+            AZ::IO::FixedMaxPathString m_fileName;
         };
 
         /**

Code/Framework/AzCore/AzCore/Serialization/EditContext.h

@@ -127,13 +127,14 @@ namespace AZ
      */
     class EditContext
     {
+    public:
         /// @cond EXCLUDE_DOCS
         class ClassBuilder;
         class EnumBuilder;
         using ClassInfo = ClassBuilder; ///< @deprecated Use EditContext::ClassBuilder
         using EnumInfo = EnumBuilder; ///< @deprecated Use EditContext::EnumBuilder
         /// @endcond
-    public:
+
         AZ_CLASS_ALLOCATOR(EditContext, SystemAllocator, 0);
 
         /**
@@ -186,6 +187,7 @@ namespace AZ
          *  look at the unit tests and example to see use cases.
          *
          */
+    public:
         class ClassBuilder
         {
             friend EditContext;
@@ -399,6 +401,7 @@ namespace AZ
             EnumBuilder* Value(const char* name, E value);
         };
 
+    private:
         typedef AZStd::list<Edit::ClassData> ClassDataListType;
         typedef AZStd::unordered_map<AZ::Uuid, Edit::ElementData> EnumDataMapType;
 

Code/Framework/AzCore/AzCore/Serialization/IdUtils.h

@@ -28,7 +28,13 @@ namespace AZ
 {
     namespace IdUtils
     {
-        template<typename IdType>
+        /**
+        * \param AllowDuplicates - If true allows the same id to be registered multiple times,
+            with the newer value overwriting the stored value. If false, duplicates are not allowed and
+            the first stored value is kept.The default is false.
+        */
+            
+        template<typename IdType, bool AllowDuplicates = false>
         struct Remapper
         {
             /**
@@ -138,14 +144,18 @@ namespace AZ
             * \param context - The serialize context for enumerating the @classPtr elements
             */
             template<typename T, typename MapType>
-            static void GenerateNewIdsAndFixRefs(T* object, MapType& newIdMap, AZ::SerializeContext* context = nullptr)
+            static void GenerateNewIdsAndFixRefs(
+                T* object, MapType& newIdMap, AZ::SerializeContext* context = nullptr)
             {
                 if (!context)
                 {
                     AZ::ComponentApplicationBus::BroadcastResult(context, &AZ::ComponentApplicationRequests::GetSerializeContext);
                     if (!context)
                     {
-                        AZ_Error("Serialization", false, "No serialize context provided! Failed to get component application default serialize context! ComponentApp is not started or input serialize context should not be null!");
+                        AZ_Error(
+                            "Serialization", false,
+                            "No serialize context provided! Failed to get component application default serialize context! ComponentApp is "
+                            "not started or input serialize context should not be null!");
                         return;
                     }
                 }
@@ -156,8 +166,16 @@ namespace AZ
                     {
                         if (idGenerator)
                         {
-                            auto it = newIdMap.emplace(originalId, idGenerator());
-                            return it.first->second;
+                            if constexpr(AllowDuplicates)
+                            {
+                                auto it = newIdMap.insert_or_assign(originalId, idGenerator());
+                                return it.first->second;
+                            }
+                            else
+                            {
+                                auto it = newIdMap.emplace(originalId, idGenerator());
+                                return it.first->second;
+                            }
                         }
                         return originalId;
                     }

Code/Framework/AzCore/AzCore/Serialization/IdUtils.inl

@@ -30,8 +30,10 @@ namespace AZ
             bool m_isModifiedContainer;
         };
 
-        template<typename IdType>
-        unsigned int Remapper<IdType>::RemapIds(void* classPtr, const AZ::Uuid& classUuid, const typename Remapper<IdType>::IdMapper& mapper, AZ::SerializeContext* context, bool replaceId)
+        template<typename IdType, bool AllowDuplicates>
+        unsigned int Remapper<IdType, AllowDuplicates>::RemapIds(
+            void* classPtr, const AZ::Uuid& classUuid, const typename Remapper<IdType, AllowDuplicates>::IdMapper& mapper,
+            AZ::SerializeContext* context, bool replaceId)
         {
             if (!context)
             {
@@ -152,16 +154,18 @@ namespace AZ
             return replaced;
         }
 
-        template<typename IdType>
-        unsigned int Remapper<IdType>::ReplaceIdsAndIdRefs(void* classPtr, const AZ::Uuid& classUuid, const IdMapper& mapper, AZ::SerializeContext* context /*= nullptr*/)
+        template<typename IdType, bool AllowDuplicates>
+        unsigned int Remapper<IdType, AllowDuplicates>::ReplaceIdsAndIdRefs(void* classPtr, const AZ::Uuid& classUuid, const IdMapper& mapper, AZ::SerializeContext* context /*= nullptr*/)
         {
             unsigned int replaced = RemapIds(classPtr, classUuid, mapper, context, true);
             replaced += RemapIds(classPtr, classUuid, mapper, context, false);
             return replaced;
         }
 
-        template<typename IdType>
-        unsigned int Remapper<IdType>::RemapIdsAndIdRefs(void* classPtr, const AZ::Uuid& classUuid, const typename Remapper<IdType>::IdReplacer& mapper, AZ::SerializeContext* context)
+        template<typename IdType, bool AllowDuplicates>
+        unsigned int Remapper<IdType, AllowDuplicates>::RemapIdsAndIdRefs(
+            void* classPtr, const AZ::Uuid& classUuid, const typename Remapper<IdType, AllowDuplicates>::IdReplacer& mapper,
+            AZ::SerializeContext* context)
         {
             if (!context)
             {

Code/Framework/AzCore/AzCore/Serialization/SerializeContext.h

@@ -101,6 +101,9 @@ namespace AZ
     class SerializeContext
         : public ReflectContext
     {
+        static const unsigned int VersionClassDeprecated = (unsigned int)-1;
+
+    public:
         /// @cond EXCLUDE_DOCS
         friend class EditContext;
         class ClassBuilder;
@@ -108,9 +111,6 @@ namespace AZ
         /// @endcond
         class EnumBuilder;
 
-        static const unsigned int VersionClassDeprecated = (unsigned int)-1;
-
-    public:
         class ClassData;
         struct EnumerateInstanceCallContext;
         struct ClassElement;
@@ -1131,6 +1131,7 @@ namespace AZ
          *      ->Version(3,&MyVersionConverter)
          *      ->Field("data",&MyStruct::m_data);
          */
+    public:
         class ClassBuilder
         {
             friend class SerializeContext;
@@ -1330,7 +1331,8 @@ namespace AZ
             AZStd::vector<AttributeSharedPair, AZStdFunctorAllocator>* m_currentAttributes = nullptr;
         };
 
-        EditContext*    m_editContext;  ///< Pointer to optional edit context.
+    private:
+        EditContext* m_editContext;  ///< Pointer to optional edit context.
         UuidToClassMap  m_uuidMap;      ///< Map for all class in this serialize context
         AZStd::unordered_multimap<AZ::Crc32, AZ::Uuid> m_classNameToUuid;  /// Map all class names to their uuid
         AZStd::unordered_multimap<Uuid, GenericClassInfo*>  m_uuidGenericMap;      ///< Uuid to ClassData map of reflected classes with GenericTypeInfo

Code/Framework/AzCore/AzCore/Settings/SettingsRegistryMergeUtils.cpp

@@ -641,6 +641,8 @@ namespace AZ::SettingsRegistryMergeUtils
         }
         else
         {
+            // Set the default ProjectUserPath to the <engine-root>/user directory
+            registry.Set(FilePathKey_ProjectUserPath, (engineRoot / "user").LexicallyNormal().Native());
             AZ_TracePrintf("SettingsRegistryMergeUtils",
                 R"(Project path isn't set in the Settings Registry at "%.*s". Project-related filepaths will not be set)" "\n",
                 aznumeric_cast<int>(projectPathKey.size()), projectPathKey.data());

Code/Framework/AzCore/AzCore/Slice/SliceComponent.h

@@ -971,6 +971,10 @@ namespace AZ
          */
         void RestoreCachedInstances();
 
+        /// Returns data flags for use when instantiating an instance of this slice.
+        /// These data flags include those harvested from the entire slice ancestry.
+        const DataFlagsPerEntity& GetDataFlagsForInstances() const;
+
     protected:
 
         //////////////////////////////////////////////////////////////////////////
@@ -1004,9 +1008,6 @@ namespace AZ
         DataFlagsPerEntity* GetCorrectBundleOfDataFlags(EntityId entityId);
         const DataFlagsPerEntity* GetCorrectBundleOfDataFlags(EntityId entityId) const;
 
-        /// Returns data flags for use when instantiating an instance of this slice.
-        /// These data flags include those harvested from the entire slice ancestry.
-        const DataFlagsPerEntity& GetDataFlagsForInstances() const;
         void BuildDataFlagsForInstances();
 
         /**

Code/Framework/AzCore/Platform/Android/AzCore/IO/SystemFile_Android.cpp

@@ -101,7 +101,7 @@ bool SystemFile::PlatformOpen(int mode, int platformFlags)
         createPath = (mode & SF_OPEN_CREATE_PATH) == SF_OPEN_CREATE_PATH;
     }
 
-    bool isApkFile = AZ::Android::Utils::IsApkPath(m_fileName);
+    bool isApkFile = AZ::Android::Utils::IsApkPath(m_fileName.c_str());
 
     if (createPath)
     {
@@ -111,19 +111,19 @@ bool SystemFile::PlatformOpen(int mode, int platformFlags)
             return false;
         }
 
-        CreatePath(m_fileName);
+        CreatePath(m_fileName.c_str());
     }
 
     int errorCode = 0;
     if (isApkFile)
     {
         AZ::u64 size = 0;
-        m_handle = AZ::Android::APKFileHandler::Open(m_fileName, openMode, size);
+        m_handle = AZ::Android::APKFileHandler::Open(m_fileName.c_str(), openMode, size);
         errorCode = EACCES; // general error when a file can't be opened from inside the APK
     }
     else
     {
-        m_handle = fopen(m_fileName, openMode);
+        m_handle = fopen(m_fileName.c_str(), openMode);
         errorCode = errno;
     }
 
@@ -233,7 +233,7 @@ namespace Platform
         }
     }
 
-    void Seek(FileHandleType handle, const SystemFile* systemFile, SizeType offset, SystemFile::SeekMode mode)
+    void Seek(FileHandleType handle, const SystemFile* systemFile, SystemFile::SeekSizeType offset, SystemFile::SeekMode mode)
     {
         if (handle != PlatformSpecificInvalidHandle)
         {

Code/Framework/AzCore/Platform/Android/AzCore/IO/SystemFile_Android.h

@@ -15,6 +15,9 @@
 #include <cstdio>
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/stat.h>
+
+#include <AzCore/std/typetraits/underlying_type.h>
 
 namespace AZ
 {
@@ -23,6 +26,7 @@ namespace AZ
         namespace Internal
         {
             using SizeType = AZ::u64;
+            using SeekSizeType = AZ::s64;
             using FileHandleType = FILE*;
         }
 
@@ -37,7 +41,7 @@ namespace AZ
 #else
                 Temporary    = 0,            // (Not applicable for this platform) Applies only when used with CREAT. Creates a file as temporary; the file is deleted when the last file descriptor is closed. PermissionMode equired when CREAT is specified.
 #endif
-                Exclusive    = O_EXCL,       // Applies only when used with CREAT. Returns an error value if a file specified by filename exists. 
+                Exclusive    = O_EXCL,       // Applies only when used with CREAT. Returns an error value if a file specified by filename exists.
                 Truncate     = O_TRUNC,      // Opens a file and truncates it to zero length; the file must have write permission. Cannot be specified with RDONLY.
                                              // Note: The TRUNC flag destroys the contents of the specified file.
 

Code/Framework/AzCore/Platform/Common/Apple/AzCore/IO/SystemFile_Apple.h

@@ -14,6 +14,9 @@
 #include <sys/syslimits.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/stat.h>
+
+#include <AzCore/std/typetraits/underlying_type.h>
 
 namespace AZ
 {
@@ -22,9 +25,10 @@ namespace AZ
         namespace Internal
         {
             using SizeType = AZ::u64;
+            using SeekSizeType = AZ::s64;
             using FileHandleType = int;
         }
-    
+
         namespace PosixInternal
         {
             enum class OpenFlags : int
@@ -36,7 +40,7 @@ namespace AZ
 #else
                 Temporary    = 0,            // (Not applicable for this platform) Applies only when used with CREAT. Creates a file as temporary; the file is deleted when the last file descriptor is closed. PermissionMode equired when CREAT is specified.
 #endif
-                Exclusive    = O_EXCL,       // Applies only when used with CREAT. Returns an error value if a file specified by filename exists. 
+                Exclusive    = O_EXCL,       // Applies only when used with CREAT. Returns an error value if a file specified by filename exists.
                 Truncate     = O_TRUNC,      // Opens a file and truncates it to zero length; the file must have write permission. Cannot be specified with RDONLY.
                                              // Note: The TRUNC flag destroys the contents of the specified file.
 

Code/Framework/AzCore/Platform/Common/UnixLike/AzCore/IO/SystemFile_UnixLike.h

@@ -13,6 +13,9 @@
 
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/stat.h>
+
+#include <AzCore/std/typetraits/underlying_type.h>
 
 namespace AZ
 {
@@ -21,6 +24,7 @@ namespace AZ
         namespace Internal
         {
             using SizeType = AZ::u64;
+            using SeekSizeType = AZ::s64;
             using FileHandleType = int;
         }
 
@@ -35,7 +39,7 @@ namespace AZ
 #else
                 Temporary    = 0,            // (Not applicable for this platform) Applies only when used with CREAT. Creates a file as temporary; the file is deleted when the last file descriptor is closed. PermissionMode equired when CREAT is specified.
 #endif
-                Exclusive    = O_EXCL,       // Applies only when used with CREAT. Returns an error value if a file specified by filename exists. 
+                Exclusive    = O_EXCL,       // Applies only when used with CREAT. Returns an error value if a file specified by filename exists.
                 Truncate     = O_TRUNC,      // Opens a file and truncates it to zero length; the file must have write permission. Cannot be specified with RDONLY.
                                              // Note: The TRUNC flag destroys the contents of the specified file.
 

Code/Framework/AzCore/Platform/Common/UnixLike/AzCore/Module/DynamicModuleHandle_UnixLike.cpp

@@ -13,9 +13,10 @@
 #include <AzCore/Module/DynamicModuleHandle.h>
 #include <AzCore/IO/Path/Path.h>
 #include <AzCore/IO/SystemFile.h>
-
 #include <AzCore/Memory/OSAllocator.h>
 #include <AzCore/Settings/SettingsRegistryMergeUtils.h>
+#include <AzCore/Utils/Utils.h>
+
 #include <dlfcn.h>
 #include <libgen.h>
 
@@ -61,10 +62,11 @@ namespace AZ
             // If it doesn't attempt to append the path to the executable path
             if (!AZ::IO::SystemFile::Exists(fullFilePath.c_str()))
             {
-                auto candidatePath = Platform::GetModulePath() / fullFilePath;
+                AZ::IO::FixedMaxPath candidatePath = Platform::GetModulePath() / fullFilePath;
                 if (AZ::IO::SystemFile::Exists(candidatePath.c_str()))
                 {
-                    fullFilePath = candidatePath;
+                    m_fileName.assign(candidatePath.Native().c_str(), candidatePath.Native().size());
+                    return;
                 }
             }
 
@@ -74,19 +76,26 @@ namespace AZ
             {
                 if (auto settingsRegistry = AZ::SettingsRegistry::Get(); settingsRegistry != nullptr)
                 {
-                    if(AZ::IO::FixedMaxPath projectModulePath;
+                    if (AZ::IO::FixedMaxPath projectModulePath;
                         settingsRegistry->Get(projectModulePath.Native(), AZ::SettingsRegistryMergeUtils::FilePathKey_ProjectConfigurationBinPath))
                     {
                         projectModulePath /= fullFilePath;
                         if (AZ::IO::SystemFile::Exists(projectModulePath.c_str()))
                         {
-                            fullFilePath = projectModulePath;
+                            m_fileName.assign(projectModulePath.c_str(), projectModulePath.Native().size());
                         }
                     }
                 }
             }
-
-            m_fileName = AZStd::string_view{fullFilePath.Native()};
+            else
+            {
+                // The module does exist (in 'cwd'), but still needs to be an absolute path for the module to be loaded.
+                AZStd::optional<AZ::IO::FixedMaxPathString> absPathOptional = AZ::Utils::ConvertToAbsolutePath(m_fileName);
+                if (absPathOptional.has_value())
+                {
+                    m_fileName.assign(absPathOptional->c_str(), absPathOptional->size());
+                }
+            }
         }
 
         ~DynamicModuleHandleUnixLike() override

Code/Framework/AzCore/Platform/Common/UnixLikeDefault/AzCore/IO/SystemFile_UnixLikeDefault.cpp

@@ -86,9 +86,9 @@ bool SystemFile::PlatformOpen(int mode, int platformFlags)
 
     if (createPath)
     {
-        CreatePath(m_fileName);
+        CreatePath(m_fileName.c_str());
     }
-    m_handle = open(m_fileName, desiredAccess, permissions);
+    m_handle = open(m_fileName.c_str(), desiredAccess, permissions);
 
     if (m_handle == PlatformSpecificInvalidHandle)
     {
@@ -119,7 +119,7 @@ namespace Platform
 {
     using FileHandleType = AZ::IO::SystemFile::FileHandleType;
 
-    void Seek(FileHandleType handle, const SystemFile* systemFile, SizeType offset, SystemFile::SeekMode mode)
+    void Seek(FileHandleType handle, const SystemFile* systemFile, SystemFile::SeekSizeType offset, SystemFile::SeekMode mode)
     {
         if (handle != PlatformSpecificInvalidHandle)
         {

Code/Framework/AzCore/Platform/Common/WinAPI/AzCore/IO/SystemFile_WinAPI.cpp

@@ -209,19 +209,19 @@ bool SystemFile::PlatformOpen(int mode, int platformFlags)
 
     if (createPath)
     {
-        CreatePath(m_fileName);
+        CreatePath(m_fileName.c_str());
     }
 
 #   ifdef _UNICODE
     wchar_t fileNameW[AZ_MAX_PATH_LEN];
     size_t numCharsConverted;
     m_handle = INVALID_HANDLE_VALUE;
-    if (mbstowcs_s(&numCharsConverted, fileNameW, m_fileName, AZ_ARRAY_SIZE(fileNameW) - 1) == 0)
+    if (mbstowcs_s(&numCharsConverted, fileNameW, m_fileName.c_str(), AZ_ARRAY_SIZE(fileNameW) - 1) == 0)
     {
         m_handle = CreateFileW(fileNameW, dwDesiredAccess, dwShareMode, 0, dwCreationDisposition, dwFlagsAndAttributes, 0);
     }
 #   else //!_UNICODE
-    m_handle = CreateFile(m_fileName, dwDesiredAccess, dwShareMode, 0, dwCreationDisposition, dwFlagsAndAttributes, 0);
+    m_handle = CreateFile(m_fileName.c_str(), dwDesiredAccess, dwShareMode, 0, dwCreationDisposition, dwFlagsAndAttributes, 0);
 #   endif // !_UNICODE
 
     if (m_handle == INVALID_HANDLE_VALUE)
@@ -261,7 +261,7 @@ namespace Platform
 {
     using FileHandleType = AZ::IO::SystemFile::FileHandleType;
 
-    void Seek(FileHandleType handle, const SystemFile* systemFile, SizeType offset, SystemFile::SeekMode mode)
+    void Seek(FileHandleType handle, const SystemFile* systemFile, SystemFile::SeekSizeType offset, SystemFile::SeekMode mode)
     {
         if (handle != PlatformSpecificInvalidHandle)
         {

Code/Framework/AzCore/Platform/Common/WinAPI/AzCore/IO/SystemFile_WinAPI.h

@@ -13,6 +13,9 @@
 
 #include <fcntl.h>
 #include <corecrt_io.h>
+#include <sys/stat.h>
+
+#include <AzCore/std/typetraits/underlying_type.h>
 
 namespace AZ
 {
@@ -21,6 +24,7 @@ namespace AZ
         namespace Internal
         {
             using SizeType = AZ::u64;
+            using SeekSizeType = AZ::s64;
             using FileHandleType = void*;
         }
 
@@ -31,7 +35,7 @@ namespace AZ
                 Append       = _O_APPEND,     // Moves the file pointer to the end of the file before every write operation.
                 Create       = _O_CREAT,      // Creates a file and opens it for writing. Has no effect if the file specified by filename exists. PermissionMode is required.
                 Temporary    = _O_TEMPORARY,  // Applies only when used with CREAT. Creates a file as temporary; the file is deleted when the last file descriptor is closed. PermissionMode equired when CREAT is specified.
-                Exclusive    = _O_EXCL,       // Applies only when used with CREAT. Returns an error value if a file specified by filename exists. 
+                Exclusive    = _O_EXCL,       // Applies only when used with CREAT. Returns an error value if a file specified by filename exists.
                 Truncate     = _O_TRUNC,      // Opens a file and truncates it to zero length; the file must have write permission. Cannot be specified with RDONLY.
                                               // Note: The TRUNC flag destroys the contents of the specified file.
 

Code/Framework/AzCore/Platform/Common/WinAPI/AzCore/Module/DynamicModuleHandle_WinAPI.cpp

@@ -24,9 +24,9 @@ namespace AZ
         : public DynamicModuleHandle
     {
     public:
-        AZ_CLASS_ALLOCATOR(DynamicModuleHandleWindows, OSAllocator, 0)
+        AZ_CLASS_ALLOCATOR(DynamicModuleHandleWindows, OSAllocator, 0);
 
-            DynamicModuleHandleWindows(const char* fullFileName)
+        DynamicModuleHandleWindows(const char* fullFileName)
             : DynamicModuleHandle(fullFileName)
             , m_handle(nullptr)
         {
@@ -52,6 +52,7 @@ namespace AZ
                     if (AZ::IO::SystemFile::Exists(candidatePath.c_str()))
                     {
                         m_fileName.assign(candidatePath.Native().c_str(), candidatePath.Native().size());
+                        return;
                     }
                 }
             }
@@ -65,7 +66,7 @@ namespace AZ
                 // Therefore an existence check is needed
                 if (auto settingsRegistry = AZ::SettingsRegistry::Get(); settingsRegistry != nullptr)
                 {
-                    if(AZ::IO::FixedMaxPath projectModulePath;
+                    if (AZ::IO::FixedMaxPath projectModulePath;
                         settingsRegistry->Get(projectModulePath.Native(), AZ::SettingsRegistryMergeUtils::FilePathKey_ProjectConfigurationBinPath))
                     {
                         projectModulePath /= AZStd::string_view(m_fileName);
@@ -76,6 +77,15 @@ namespace AZ
                     }
                 }
             }
+            else
+            {
+                // The module does exist (in 'cwd'), but still needs to be an absolute path for the module to be loaded.
+                AZStd::optional<AZ::IO::FixedMaxPathString> absPathOptional = AZ::Utils::ConvertToAbsolutePath(m_fileName);
+                if (absPathOptional.has_value())
+                {
+                    m_fileName.assign(absPathOptional->c_str(), absPathOptional->size());
+                }
+            }
         }
 
         ~DynamicModuleHandleWindows() override

Code/Framework/AzCore/Tests/AZStd/String.cpp

@@ -1914,7 +1914,7 @@ namespace UnitTest
     TEST_F(String, StringView_CompareIsConstexpr)
     {
         using TypeParam = char;
-        auto MakeCompileTimeString1 = []() constexpr -> const TypeParam*
+        auto ThisTestMakeCompileTimeString1 = []() constexpr -> const TypeParam*
         {
             return "HelloWorld";
         };
@@ -1922,7 +1922,7 @@ namespace UnitTest
         {
             return "HelloPearl";
         };
-        constexpr const TypeParam* compileTimeString1 = MakeCompileTimeString1();
+        constexpr const TypeParam* compileTimeString1 = ThisTestMakeCompileTimeString1();
         constexpr const TypeParam* compileTimeString2 = MakeCompileTimeString2();
         constexpr basic_string_view<TypeParam> lhsView(compileTimeString1);
         constexpr basic_string_view<TypeParam> rhsView(compileTimeString2);
@@ -1937,11 +1937,11 @@ namespace UnitTest
     TEST_F(String, StringView_CompareOperatorsAreConstexpr)
     {
         using TypeParam = char;
-        auto MakeCompileTimeString1 = []() constexpr -> const TypeParam*
+        auto TestMakeCompileTimeString1 = []() constexpr -> const TypeParam*
         {
             return "HelloWorld";
         };
-        constexpr const TypeParam* compileTimeString1 = MakeCompileTimeString1();
+        constexpr const TypeParam* compileTimeString1 = TestMakeCompileTimeString1();
         constexpr basic_string_view<TypeParam> compareView(compileTimeString1);
         static_assert(compareView == "HelloWorld", "string_view operator== comparison has failed");
         static_assert(compareView != "MadWorld", "string_view operator!= comparison has failed");
@@ -1955,7 +1955,7 @@ namespace UnitTest
     {
         auto swap_test_func = []() constexpr -> basic_string_view<TypeParam>
         {
-            constexpr auto MakeCompileTimeString1 = []() constexpr -> const TypeParam*
+            constexpr auto ThisTestMakeCompileTimeString1 = []() constexpr -> const TypeParam*
             {
                 if constexpr (AZStd::is_same_v<TypeParam, char>)
                 {
@@ -1977,7 +1977,7 @@ namespace UnitTest
                     return L"InuWorld";
                 }
             };
-            constexpr const TypeParam* compileTimeString1 = MakeCompileTimeString1();
+            constexpr const TypeParam* compileTimeString1 = ThisTestMakeCompileTimeString1();
             constexpr const TypeParam* compileTimeString2 = MakeCompileTimeString2();
             basic_string_view<TypeParam> lhsView(compileTimeString1);
             basic_string_view<TypeParam> rhsView(compileTimeString2);
@@ -2001,7 +2001,7 @@ namespace UnitTest
 
     TYPED_TEST(BasicStringViewConstexprFixture, HashString_FunctionIsConstexpr)
     {
-        auto MakeCompileTimeString1 = []() constexpr -> const TypeParam*
+        auto ThisTestMakeCompileTimeString1 = []() constexpr -> const TypeParam*
         {
             if constexpr (AZStd::is_same_v<TypeParam, char>)
             {
@@ -2012,7 +2012,7 @@ namespace UnitTest
                 return L"HelloWorld";
             }
         };
-        constexpr const TypeParam* compileTimeString1 = MakeCompileTimeString1();
+        constexpr const TypeParam* compileTimeString1 = ThisTestMakeCompileTimeString1();
         constexpr basic_string_view<TypeParam> hashView(compileTimeString1);
         constexpr size_t compileHash = AZStd::hash<basic_string_view<TypeParam>>{}(hashView);
         static_assert(compileHash != 0, "Hash of \"HelloWorld\" should not be 0");

Code/Framework/AzCore/Tests/Jobs.cpp

@@ -395,7 +395,8 @@ namespace UnitTest
             }
             else
             {
-                int result1, result2;
+                int result1 = 0;
+                int result2 = 0;
                 Job* job1 = aznew FibonacciJob2(m_n - 1, &result1, m_context);
                 Job* job2 = aznew FibonacciJob2(m_n - 2, &result2, m_context);
                 StartAsChild(job1);

Code/Framework/AzCore/Tests/Math/Matrix4x4Tests.cpp

@@ -59,7 +59,7 @@ namespace UnitTest
 
     TEST(MATH_Matrix4x4, TestCreateFrom)
     {
-        float testFloats[] =
+        float thisTestFloats[] =
         {
              1.0f,  2.0f,  3.0f,  4.0f,
              5.0f,  6.0f,  7.0f,  8.0f,
@@ -67,20 +67,20 @@ namespace UnitTest
             13.0f, 14.0f, 15.0f, 16.0f
         };
         float testFloatMtx[16];
-        Matrix4x4 m1 = Matrix4x4::CreateFromRowMajorFloat16(testFloats);
+        Matrix4x4 m1 = Matrix4x4::CreateFromRowMajorFloat16(thisTestFloats);
         AZ_TEST_ASSERT(m1.GetRow(0) == Vector4(1.0f, 2.0f, 3.0f, 4.0f));
         AZ_TEST_ASSERT(m1.GetRow(1) == Vector4(5.0f, 6.0f, 7.0f, 8.0f));
         AZ_TEST_ASSERT(m1.GetRow(2) == Vector4(9.0f, 10.0f, 11.0f, 12.0f));
         AZ_TEST_ASSERT(m1.GetRow(3) == Vector4(13.0f, 14.0f, 15.0f, 16.0f));
         m1.StoreToRowMajorFloat16(testFloatMtx);
-        AZ_TEST_ASSERT(memcmp(testFloatMtx, testFloats, sizeof(testFloatMtx)) == 0);
-        m1 = Matrix4x4::CreateFromColumnMajorFloat16(testFloats);
+        AZ_TEST_ASSERT(memcmp(testFloatMtx, thisTestFloats, sizeof(testFloatMtx)) == 0);
+        m1 = Matrix4x4::CreateFromColumnMajorFloat16(thisTestFloats);
         AZ_TEST_ASSERT(m1.GetRow(0) == Vector4(1.0f, 5.0f, 9.0f, 13.0f));
         AZ_TEST_ASSERT(m1.GetRow(1) == Vector4(2.0f, 6.0f, 10.0f, 14.0f));
         AZ_TEST_ASSERT(m1.GetRow(2) == Vector4(3.0f, 7.0f, 11.0f, 15.0f));
         AZ_TEST_ASSERT(m1.GetRow(3) == Vector4(4.0f, 8.0f, 12.0f, 16.0f));
         m1.StoreToColumnMajorFloat16(testFloatMtx);
-        AZ_TEST_ASSERT(memcmp(testFloatMtx, testFloats, sizeof(testFloatMtx)) == 0);
+        AZ_TEST_ASSERT(memcmp(testFloatMtx, thisTestFloats, sizeof(testFloatMtx)) == 0);
     }
 
     TEST(MATH_Matrix4x4, TestCreateFromMatrix3x4)

Code/Framework/AzCore/Tests/Math/ObbTests.cpp

@@ -119,10 +119,10 @@ namespace UnitTest
 
     TEST(MATH_Obb, Contains)
     {
-        const Vector3 position(1.0f, 2.0f, 3.0f);
-        const Quaternion rotation = Quaternion::CreateRotationZ(DegToRad(30.0f));
-        const Vector3 halfLengths(2.0f, 1.0f, 2.5f);
-        const Obb obb = Obb::CreateFromPositionRotationAndHalfLengths(position, rotation, halfLengths);
+        const Vector3 testPosition(1.0f, 2.0f, 3.0f);
+        const Quaternion testRotation = Quaternion::CreateRotationZ(DegToRad(30.0f));
+        const Vector3 testHalfLengths(2.0f, 1.0f, 2.5f);
+        const Obb obb = Obb::CreateFromPositionRotationAndHalfLengths(testPosition, testRotation, testHalfLengths);
         // test some pairs of points which should be just either side of the Obb boundary
         EXPECT_TRUE(obb.Contains(Vector3(1.35f, 3.35f, 3.5f)));
         EXPECT_FALSE(obb.Contains(Vector3(1.35f, 3.4f, 3.5f)));
@@ -134,10 +134,10 @@ namespace UnitTest
 
     TEST(MATH_Obb, GetDistance)
     {
-        const Vector3 position(5.0f, 3.0f, 2.0f);
-        const Quaternion rotation = Quaternion::CreateRotationX(DegToRad(60.0f));
-        const Vector3 halfLengths(0.5f, 2.0f, 1.5f);
-        const Obb obb = Obb::CreateFromPositionRotationAndHalfLengths(position, rotation, halfLengths);
+        const Vector3 testPosition(5.0f, 3.0f, 2.0f);
+        const Quaternion testRotation = Quaternion::CreateRotationX(DegToRad(60.0f));
+        const Vector3 testHalfLengths(0.5f, 2.0f, 1.5f);
+        const Obb obb = Obb::CreateFromPositionRotationAndHalfLengths(testPosition, testRotation, testHalfLengths);
         EXPECT_NEAR(obb.GetDistance(Vector3(5.3f, 3.2f, 1.8f)), 0.0f, 1e-3f);
         EXPECT_NEAR(obb.GetDistance(Vector3(5.1f, 1.1f, 3.7f)), 0.9955f, 1e-3f);
         EXPECT_NEAR(obb.GetDistance(Vector3(4.7f, 4.5f, 4.2f)), 0.6553f, 1e-3f);
@@ -146,10 +146,10 @@ namespace UnitTest
 
     TEST(MATH_Obb, GetDistanceSq)
     {
-        const Vector3 position(1.0f, 4.0f, 3.0f);
-        const Quaternion rotation = Quaternion::CreateRotationY(DegToRad(45.0f));
-        const Vector3 halfLengths(1.5f, 3.0f, 1.0f);
-        const Obb obb = Obb::CreateFromPositionRotationAndHalfLengths(position, rotation, halfLengths);
+        const Vector3 testPosition(1.0f, 4.0f, 3.0f);
+        const Quaternion testRotation = Quaternion::CreateRotationY(DegToRad(45.0f));
+        const Vector3 testHalfLengths(1.5f, 3.0f, 1.0f);
+        const Obb obb = Obb::CreateFromPositionRotationAndHalfLengths(testPosition, testRotation, testHalfLengths);
         EXPECT_NEAR(obb.GetDistanceSq(Vector3(1.1f, 4.3f, 2.7f)), 0.0f, 1e-3f);
         EXPECT_NEAR(obb.GetDistanceSq(Vector3(-0.7f, 3.5f, 2.0f)), 0.8266f, 1e-3f);
         EXPECT_NEAR(obb.GetDistanceSq(Vector3(2.4f, 0.5f, 1.5f)), 0.5532f, 1e-3f);

Code/Framework/AzFramework/AzFramework/Application/Application.cpp

@@ -711,8 +711,8 @@ namespace AzFramework
                 }
             }
 
-            AZ::IO::FixedMaxPath projectUserPath;
-            if (m_settingsRegistry->Get(projectUserPath.Native(), AZ::SettingsRegistryMergeUtils::FilePathKey_ProjectUserPath))
+            if (AZ::IO::FixedMaxPath projectUserPath;
+                m_settingsRegistry->Get(projectUserPath.Native(), AZ::SettingsRegistryMergeUtils::FilePathKey_ProjectUserPath))
             {
                 fileIoBase->SetAlias("@user@", projectUserPath.c_str());
                 AZ::IO::FixedMaxPath projectLogPath = projectUserPath / "log";
@@ -721,6 +721,15 @@ namespace AzFramework
 
                 CreateUserCache(projectUserPath, *fileIoBase);
             }
+            else
+            {
+                AZ::IO::FixedMaxPath fallbackLogPath = GetEngineRoot();
+                fallbackLogPath /= "user";
+                fileIoBase->SetAlias("@user@", fallbackLogPath.c_str());
+                fallbackLogPath /= "log";
+                fileIoBase->SetAlias("@log@", fallbackLogPath.c_str());
+                fileIoBase->CreatePath(fallbackLogPath.c_str());
+            }
         }
     }
 

Code/Framework/AzFramework/AzFramework/Spawnable/SpawnableEntitiesContainer.cpp

@@ -38,20 +38,20 @@ namespace AzFramework
     void SpawnableEntitiesContainer::SpawnAllEntities()
     {
         AZ_Assert(m_threadData, "Calling SpawnAllEntities on a Spawnable container that's not set.");
-        SpawnableEntitiesInterface::Get()->SpawnAllEntities(m_threadData->m_spawnedEntitiesTicket, SpawnablePriority_Default);
+        SpawnableEntitiesInterface::Get()->SpawnAllEntities(m_threadData->m_spawnedEntitiesTicket);
     }
 
     void SpawnableEntitiesContainer::SpawnEntities(AZStd::vector<size_t> entityIndices)
     {
         AZ_Assert(m_threadData, "Calling SpawnEntities on a Spawnable container that's not set.");
         SpawnableEntitiesInterface::Get()->SpawnEntities(
-            m_threadData->m_spawnedEntitiesTicket, SpawnablePriority_Default, AZStd::move(entityIndices));
+            m_threadData->m_spawnedEntitiesTicket, AZStd::move(entityIndices));
     }
 
     void SpawnableEntitiesContainer::DespawnAllEntities()
     {
         AZ_Assert(m_threadData, "Calling DespawnEntities on a Spawnable container that's not set.");
-        SpawnableEntitiesInterface::Get()->DespawnAllEntities(m_threadData->m_spawnedEntitiesTicket, SpawnablePriority_Default);
+        SpawnableEntitiesInterface::Get()->DespawnAllEntities(m_threadData->m_spawnedEntitiesTicket);
     }
 
     void SpawnableEntitiesContainer::Reset(AZ::Data::Asset<Spawnable> spawnable)
@@ -69,7 +69,6 @@ namespace AzFramework
 
             SpawnableEntitiesInterface::Get()->Barrier(
                 m_threadData->m_spawnedEntitiesTicket,
-                SpawnablePriority_Default,
                 [threadData = m_threadData](EntitySpawnTicket::Id) mutable
                 {
                     threadData.reset();
@@ -88,7 +87,6 @@ namespace AzFramework
         AZ_Assert(m_threadData, "Calling DespawnEntities on a Spawnable container that's not set.");
         SpawnableEntitiesInterface::Get()->Barrier(
             m_threadData->m_spawnedEntitiesTicket,
-            SpawnablePriority_Default,
             [generation = m_threadData->m_generation, callback = AZStd::move(callback)](EntitySpawnTicket::Id)
             {
                 callback(generation);
@@ -115,7 +113,6 @@ namespace AzFramework
         AZ_Assert(m_threadData, "SpawnableEntitiesContainer is monitoring a spawnable, but doesn't have the associated data.");
 
         AZ_TracePrintf("Spawnables", "Reloading spawnable '%s'.\n", replacementAsset.GetHint().c_str());
-        SpawnableEntitiesInterface::Get()->ReloadSpawnable(
-            m_threadData->m_spawnedEntitiesTicket, SpawnablePriority_Default, AZStd::move(replacementAsset));
+        SpawnableEntitiesInterface::Get()->ReloadSpawnable(m_threadData->m_spawnedEntitiesTicket, AZStd::move(replacementAsset));
     }
 } // namespace AzFramework

Code/Framework/AzFramework/AzFramework/Spawnable/SpawnableEntitiesInterface.h

@@ -21,6 +21,7 @@
 namespace AZ
 {
     class Entity;
+    class SerializeContext;
 }
 
 namespace AzFramework
@@ -171,6 +172,77 @@ namespace AzFramework
     using ClaimEntitiesCallback = AZStd::function<void(EntitySpawnTicket::Id, SpawnableEntityContainerView)>;
     using BarrierCallback = AZStd::function<void(EntitySpawnTicket::Id)>;
 
+    struct SpawnAllEntitiesOptionalArgs final
+    {
+        //! Callback that's called after instances of entities have been created, but before they're spawned into the world. This
+        //!     gives the opportunity to modify the entities if needed such as injecting additional components or modifying components.
+        EntityPreInsertionCallback m_preInsertionCallback;
+        //! Callback that's called when spawning entities has completed. This can be triggered from a different thread than the one that
+        //!     made the function call to spawn. The returned list of entities contains all the newly created entities.
+        EntitySpawnCallback m_completionCallback;
+        //! The Serialize Context used to clone entities with. If this is not provided the global Serialize Contetx will be used.
+        AZ::SerializeContext* m_serializeContext { nullptr };
+        //! The priority at which this call will be executed.
+        SpawnablePriority m_priority { SpawnablePriority_Default };
+    };
+
+    struct SpawnEntitiesOptionalArgs final
+    {
+        //! Callback that's called after instances of entities have been created, but before they're spawned into the world. This
+        //!     gives the opportunity to modify the entities if needed such as injecting additional components or modifying components.
+        EntityPreInsertionCallback m_preInsertionCallback;
+        //! Callback that's called when spawning entities has completed. This can be triggered from a different thread than the one that
+        //!     made the function call to spawn. The returned list of entities contains all the newly created entities.
+        EntitySpawnCallback m_completionCallback;
+        //! The Serialize Context used to clone entities with. If this is not provided the global Serialize Contetx will be used.
+        AZ::SerializeContext* m_serializeContext{ nullptr };
+        //! The priority at which this call will be executed.
+        SpawnablePriority m_priority{ SpawnablePriority_Default };
+        //! Entity references are resolved by referring to the last entity spawned from a template entity in the spawnable. If this
+        //! is set to false entities from previous spawn calls are not taken into account. If set to true entity references may be
+        //! resolved to a previously spawned entity. A lookup table has to be constructed when true, which may negatively impact
+        //! performance, especially if a large number of entities are present on a ticket.
+        bool m_referencePreviouslySpawnedEntities{ false };
+    };
+
+    struct DespawnAllEntitiesOptionalArgs final
+    {
+        //! Callback that's called when despawning entities has completed. This can be triggered from a different thread than the one that
+        //!     made the function call to despawn. The returned list of entities contains all the newly created entities.
+        EntityDespawnCallback m_completionCallback;
+        //! The priority at which this call will be executed.
+        SpawnablePriority m_priority { SpawnablePriority_Default };
+    };
+
+    struct ReloadSpawnableOptionalArgs final
+    {
+        //! Callback that's called when respawning entities has completed. This can be triggered from a different thread than the one that
+        //!     made the function call to respawn. The returned list of entities contains all the newly created entities.
+        ReloadSpawnableCallback m_completionCallback;
+        //! The Serialize Context used to clone entities with. If this is not provided the global Serialize Context will be used.
+        AZ::SerializeContext* m_serializeContext { nullptr };
+        //! The priority at which this call will be executed.
+        SpawnablePriority m_priority { SpawnablePriority_Default };
+    };
+
+    struct ListEntitiesOptionalArgs final
+    {
+        //! The priority at which this call will be executed.
+        SpawnablePriority m_priority{ SpawnablePriority_Default };
+    };
+
+    struct ClaimEntitiesOptionalArgs final
+    {
+        //! The priority at which this call will be executed.
+        SpawnablePriority m_priority{ SpawnablePriority_Default };
+    };
+
+    struct BarrierOptionalArgs final
+    {
+        //! The priority at which this call will be executed.
+        SpawnablePriority m_priority{ SpawnablePriority_Default };
+    };
+
     //! Interface definition to (de)spawn entities from a spawnable into the game world.
     //! 
     //! While the callbacks of the individual calls are being processed they will block processing any other request. Callbacks can be
@@ -196,47 +268,34 @@ namespace AzFramework
 
         //! Spawn instances of all entities in the spawnable.
         //! @param ticket Stores the results of the call. Use this ticket to spawn additional entities or to despawn them.
-        //! @param priority The priority at which this call will be executed.
-        //! @param completionCallback Optional callback that's called when spawning entities has completed. This can be called from
-        //!     a different thread than the one that made the function call. The returned list of entities contains all the newly
-        //!     created entities.
-        virtual void SpawnAllEntities(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, EntityPreInsertionCallback preInsertionCallback = {},
-            EntitySpawnCallback completionCallback = {}) = 0;
+        //! @param optionalArgs Optional additional arguments, see SpawnAllEntitiesOptionalArgs.
+        virtual void SpawnAllEntities(EntitySpawnTicket& ticket, SpawnAllEntitiesOptionalArgs optionalArgs = {}) = 0;
         //! Spawn instances of some entities in the spawnable.
         //! @param ticket Stores the results of the call. Use this ticket to spawn additional entities or to despawn them.
         //! @param priority The priority at which this call will be executed.
         //! @param entityIndices The indices into the template entities stored in the spawnable that will be used to spawn entities from.
-        //! @param completionCallback Optional callback that's called when spawning entities has completed. This can be called from
-        //!     a different thread than the one that made this function call. The returned list of entities contains all the newly
-        //!     created entities.
+        //! @param optionalArgs Optional additional arguments, see SpawnEntitiesOptionalArgs.
         virtual void SpawnEntities(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, AZStd::vector<size_t> entityIndices,
-            EntityPreInsertionCallback preInsertionCallback = {}, EntitySpawnCallback completionCallback = {}) = 0;
+            EntitySpawnTicket& ticket, AZStd::vector<size_t> entityIndices, SpawnEntitiesOptionalArgs optionalArgs = {}) = 0;
         //! Removes all entities in the provided list from the environment.
         //! @param ticket The ticket previously used to spawn entities with.
         //! @param priority The priority at which this call will be executed.
-        //! @param completionCallback Optional callback that's called when despawning entities has completed. This can be called from
-        //!     a different thread than the one that made this function call.
-        virtual void DespawnAllEntities(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, EntityDespawnCallback completionCallback = {}) = 0;
-
+        //! @param optionalArgs Optional additional arguments, see DespawnAllEntitiesOptionalArgs.
+        virtual void DespawnAllEntities(EntitySpawnTicket& ticket, DespawnAllEntitiesOptionalArgs optionalArgs = {}) = 0;
         //! Removes all entities in the provided list from the environment and reconstructs the entities from the provided spawnable.
         //! @param ticket Holds the information on the entities to reload.
         //! @param priority The priority at which this call will be executed.
         //! @param spawnable The spawnable that will replace the existing spawnable. Both need to have the same asset id.
-        //! @param completionCallback Optional callback that's called when the entities have been reloaded. This can be called from
-        //!     a different thread than the one that made this function call. The returned list of entities contains all the replacement
-        //!     entities.
+        //! @param optionalArgs Optional additional arguments, see ReloadSpawnableOptionalArgs.
         virtual void ReloadSpawnable(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, AZ::Data::Asset<Spawnable> spawnable,
-            ReloadSpawnableCallback completionCallback = {}) = 0;
+            EntitySpawnTicket& ticket, AZ::Data::Asset<Spawnable> spawnable, ReloadSpawnableOptionalArgs optionalArgs = {}) = 0;
 
         //! List all entities that are spawned using this ticket.
         //! @param ticket Only the entities associated with this ticket will be listed.
-        //! @param priority The priority at which this call will be executed.
         //! @param listCallback Required callback that will be called to list the entities on.
-        virtual void ListEntities(EntitySpawnTicket& ticket, SpawnablePriority priority, ListEntitiesCallback listCallback) = 0;
+        //! @param optionalArgs Optional additional arguments, see ListEntitiesOptionalArgs.
+        virtual void ListEntities(
+            EntitySpawnTicket& ticket, ListEntitiesCallback listCallback, ListEntitiesOptionalArgs optionalArgs = {}) = 0;
         //! List all entities that are spawned using this ticket with their spawnable index.
         //!     Spawnables contain a flat list of entities, which are used as templates to spawn entities from. For every spawned entity
         //!     the index of the entity in the spawnable that was used as a template is stored. This version of ListEntities will return
@@ -244,23 +303,24 @@ namespace AzFramework
         //!     the same index may appear multiple times as there are no restriction on how many instance of a specific entity can be
         //!     created.
         //! @param ticket Only the entities associated with this ticket will be listed.
-        //! @param priority The priority at which this call will be executed.
         //! @param listCallback Required callback that will be called to list the entities and indices on.
+        //! @param optionalArgs Optional additional arguments, see ListEntitiesOptionalArgs.
         virtual void ListIndicesAndEntities(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, ListIndicesEntitiesCallback listCallback) = 0;
+            EntitySpawnTicket& ticket, ListIndicesEntitiesCallback listCallback, ListEntitiesOptionalArgs optionalArgs = {}) = 0;
         //! Claim all entities that are spawned using this ticket. Ownership of the entities is transferred from the ticket to the
         //!     caller through the callback. After this call the ticket will have no entities associated with it. The caller of
         //!     this function will need to manage the entities after this call.
         //! @param ticket Only the entities associated with this ticket will be released.
-        //! @param priority The priority at which this call will be executed.
         //! @param listCallback Required callback that will be called to transfer the entities through.
-        virtual void ClaimEntities(EntitySpawnTicket& ticket, SpawnablePriority priority, ClaimEntitiesCallback listCallback) = 0;
+        //! @param optionalArgs Optional additional arguments, see ClaimEntitiesOptionalArgs.
+        virtual void ClaimEntities(
+            EntitySpawnTicket& ticket, ClaimEntitiesCallback listCallback, ClaimEntitiesOptionalArgs optionalArgs = {}) = 0;
 
         //! Blocks until all operations made on the provided ticket before the barrier call have completed.
         //! @param ticket The ticket to monitor.
-        //! @param priority The priority at which this call will be executed.
         //! @param completionCallback Required callback that will be called as soon as the barrier has been reached.
-        virtual void Barrier(EntitySpawnTicket& ticket, SpawnablePriority priority, BarrierCallback completionCallback) = 0;
+        //! @param optionalArgs Optional additional arguments, see BarrierOptionalArgs.
+        virtual void Barrier(EntitySpawnTicket& ticket, BarrierCallback completionCallback, BarrierOptionalArgs optionalArgs = {}) = 0;
 
         //! Register a handler for OnSpawned events.
         virtual void AddOnSpawnedHandler(AZ::Event<AZ::Data::Asset<Spawnable>>::Handler& handler) = 0;

Code/Framework/AzFramework/AzFramework/Spawnable/SpawnableEntitiesManager.cpp

@@ -38,6 +38,10 @@ namespace AzFramework
 
     SpawnableEntitiesManager::SpawnableEntitiesManager()
     {
+        AZ::ComponentApplicationBus::BroadcastResult(m_defaultSerializeContext, &AZ::ComponentApplicationBus::Events::GetSerializeContext);
+        AZ_Assert(
+            m_defaultSerializeContext, "Failed to retrieve serialization context during construction of the Spawnable Entities Manager.");
+
         if (auto settingsRegistry = AZ::SettingsRegistry::Get(); settingsRegistry != nullptr)
         {
             AZ::u64 value = aznumeric_caster(m_highPriorityThreshold);
@@ -46,58 +50,61 @@ namespace AzFramework
         }
     }
 
-    void SpawnableEntitiesManager::SpawnAllEntities(
-        EntitySpawnTicket& ticket, SpawnablePriority priority, EntityPreInsertionCallback preInsertionCallback,
-        EntitySpawnCallback completionCallback)
+    void SpawnableEntitiesManager::SpawnAllEntities(EntitySpawnTicket& ticket, SpawnAllEntitiesOptionalArgs optionalArgs)
     {
         AZ_Assert(ticket.IsValid(), "Ticket provided to SpawnAllEntities hasn't been initialized.");
 
         SpawnAllEntitiesCommand queueEntry;
         queueEntry.m_ticketId = ticket.GetId();
-        queueEntry.m_completionCallback = AZStd::move(completionCallback);
-        queueEntry.m_preInsertionCallback = AZStd::move(preInsertionCallback);
-        QueueRequest(ticket, priority, AZStd::move(queueEntry));
+        queueEntry.m_serializeContext =
+            optionalArgs.m_serializeContext == nullptr ? m_defaultSerializeContext : optionalArgs.m_serializeContext;
+        queueEntry.m_completionCallback = AZStd::move(optionalArgs.m_completionCallback);
+        queueEntry.m_preInsertionCallback = AZStd::move(optionalArgs.m_preInsertionCallback);
+        QueueRequest(ticket, optionalArgs.m_priority, AZStd::move(queueEntry));
     }
 
     void SpawnableEntitiesManager::SpawnEntities(
-        EntitySpawnTicket& ticket, SpawnablePriority priority, AZStd::vector<size_t> entityIndices,
-        EntityPreInsertionCallback preInsertionCallback, EntitySpawnCallback completionCallback)
+        EntitySpawnTicket& ticket, AZStd::vector<size_t> entityIndices, SpawnEntitiesOptionalArgs optionalArgs)
     {
         AZ_Assert(ticket.IsValid(), "Ticket provided to SpawnEntities hasn't been initialized.");
 
         SpawnEntitiesCommand queueEntry;
         queueEntry.m_ticketId = ticket.GetId();
         queueEntry.m_entityIndices = AZStd::move(entityIndices);
-        queueEntry.m_completionCallback = AZStd::move(completionCallback);
-        queueEntry.m_preInsertionCallback = AZStd::move(preInsertionCallback);
-        QueueRequest(ticket, priority, AZStd::move(queueEntry));
+        queueEntry.m_serializeContext =
+            optionalArgs.m_serializeContext == nullptr ? m_defaultSerializeContext : optionalArgs.m_serializeContext;
+        queueEntry.m_completionCallback = AZStd::move(optionalArgs.m_completionCallback);
+        queueEntry.m_preInsertionCallback = AZStd::move(optionalArgs.m_preInsertionCallback);
+        queueEntry.m_referencePreviouslySpawnedEntities = optionalArgs.m_referencePreviouslySpawnedEntities;
+        QueueRequest(ticket, optionalArgs.m_priority, AZStd::move(queueEntry));
     }
 
-    void SpawnableEntitiesManager::DespawnAllEntities(
-        EntitySpawnTicket& ticket, SpawnablePriority priority, EntityDespawnCallback completionCallback)
+    void SpawnableEntitiesManager::DespawnAllEntities(EntitySpawnTicket& ticket, DespawnAllEntitiesOptionalArgs optionalArgs)
     {
         AZ_Assert(ticket.IsValid(), "Ticket provided to DespawnAllEntities hasn't been initialized.");
 
         DespawnAllEntitiesCommand queueEntry;
         queueEntry.m_ticketId = ticket.GetId();
-        queueEntry.m_completionCallback = AZStd::move(completionCallback);
-        QueueRequest(ticket, priority, AZStd::move(queueEntry));
+        queueEntry.m_completionCallback = AZStd::move(optionalArgs.m_completionCallback);
+        QueueRequest(ticket, optionalArgs.m_priority, AZStd::move(queueEntry));
     }
 
     void SpawnableEntitiesManager::ReloadSpawnable(
-        EntitySpawnTicket& ticket, SpawnablePriority priority, AZ::Data::Asset<Spawnable> spawnable,
-        ReloadSpawnableCallback completionCallback)
+        EntitySpawnTicket& ticket, AZ::Data::Asset<Spawnable> spawnable, ReloadSpawnableOptionalArgs optionalArgs)
     {
         AZ_Assert(ticket.IsValid(), "Ticket provided to ReloadSpawnable hasn't been initialized.");
 
         ReloadSpawnableCommand queueEntry;
         queueEntry.m_ticketId = ticket.GetId();
         queueEntry.m_spawnable = AZStd::move(spawnable);
-        queueEntry.m_completionCallback = AZStd::move(completionCallback);
-        QueueRequest(ticket, priority, AZStd::move(queueEntry));
+        queueEntry.m_serializeContext =
+            optionalArgs.m_serializeContext == nullptr ? m_defaultSerializeContext : optionalArgs.m_serializeContext;
+        queueEntry.m_completionCallback = AZStd::move(optionalArgs.m_completionCallback);
+        QueueRequest(ticket, optionalArgs.m_priority, AZStd::move(queueEntry));
     }
 
-    void SpawnableEntitiesManager::ListEntities(EntitySpawnTicket& ticket, SpawnablePriority priority, ListEntitiesCallback listCallback)
+    void SpawnableEntitiesManager::ListEntities(
+        EntitySpawnTicket& ticket, ListEntitiesCallback listCallback, ListEntitiesOptionalArgs optionalArgs)
     {
         AZ_Assert(listCallback, "ListEntities called on spawnable entities without a valid callback to use.");
         AZ_Assert(ticket.IsValid(), "Ticket provided to ListEntities hasn't been initialized.");
@@ -105,11 +112,11 @@ namespace AzFramework
         ListEntitiesCommand queueEntry;
         queueEntry.m_ticketId = ticket.GetId();
         queueEntry.m_listCallback = AZStd::move(listCallback);
-        QueueRequest(ticket, priority, AZStd::move(queueEntry));
+        QueueRequest(ticket, optionalArgs.m_priority, AZStd::move(queueEntry));
     }
 
     void SpawnableEntitiesManager::ListIndicesAndEntities(
-        EntitySpawnTicket& ticket, SpawnablePriority priority, ListIndicesEntitiesCallback listCallback)
+        EntitySpawnTicket& ticket, ListIndicesEntitiesCallback listCallback, ListEntitiesOptionalArgs optionalArgs)
     {
         AZ_Assert(listCallback, "ListEntities called on spawnable entities without a valid callback to use.");
         AZ_Assert(ticket.IsValid(), "Ticket provided to ListEntities hasn't been initialized.");
@@ -117,10 +124,11 @@ namespace AzFramework
         ListIndicesEntitiesCommand queueEntry;
         queueEntry.m_ticketId = ticket.GetId();
         queueEntry.m_listCallback = AZStd::move(listCallback);
-        QueueRequest(ticket, priority, AZStd::move(queueEntry));
+        QueueRequest(ticket, optionalArgs.m_priority, AZStd::move(queueEntry));
     }
 
-    void SpawnableEntitiesManager::ClaimEntities(EntitySpawnTicket& ticket, SpawnablePriority priority, ClaimEntitiesCallback listCallback)
+    void SpawnableEntitiesManager::ClaimEntities(
+        EntitySpawnTicket& ticket, ClaimEntitiesCallback listCallback, ClaimEntitiesOptionalArgs optionalArgs)
     {
         AZ_Assert(listCallback, "ClaimEntities called on spawnable entities without a valid callback to use.");
         AZ_Assert(ticket.IsValid(), "Ticket provided to ClaimEntities hasn't been initialized.");
@@ -128,10 +136,10 @@ namespace AzFramework
         ClaimEntitiesCommand queueEntry;
         queueEntry.m_ticketId = ticket.GetId();
         queueEntry.m_listCallback = AZStd::move(listCallback);
-        QueueRequest(ticket, priority, AZStd::move(queueEntry));
+        QueueRequest(ticket, optionalArgs.m_priority, AZStd::move(queueEntry));
     }
 
-    void SpawnableEntitiesManager::Barrier(EntitySpawnTicket& ticket, SpawnablePriority priority, BarrierCallback completionCallback)
+    void SpawnableEntitiesManager::Barrier(EntitySpawnTicket& ticket, BarrierCallback completionCallback, BarrierOptionalArgs optionalArgs)
     {
         AZ_Assert(completionCallback, "Barrier on spawnable entities called without a valid callback to use.");
         AZ_Assert(ticket.IsValid(), "Ticket provided to Barrier hasn't been initialized.");
@@ -139,7 +147,7 @@ namespace AzFramework
         BarrierCommand queueEntry;
         queueEntry.m_ticketId = ticket.GetId();
         queueEntry.m_completionCallback = AZStd::move(completionCallback);
-        QueueRequest(ticket, priority, AZStd::move(queueEntry));
+        QueueRequest(ticket, optionalArgs.m_priority, AZStd::move(queueEntry));
     }
 
     void SpawnableEntitiesManager::AddOnSpawnedHandler(AZ::Event<AZ::Data::Asset<Spawnable>>::Handler& handler)
@@ -174,58 +182,57 @@ namespace AzFramework
 
     auto SpawnableEntitiesManager::ProcessQueue(Queue& queue) -> CommandQueueStatus
     {
-        AZStd::queue<Requests> pendingRequestQueue;
+        // Process delayed requests first.
+        // Only process the requests that are currently in this queue, not the ones that could be re-added if they still can't complete.
+        size_t delayedSize = queue.m_delayed.size();
+        for (size_t i = 0; i < delayedSize; ++i)
         {
-            AZStd::scoped_lock queueLock(queue.m_pendingRequestMutex);
-            queue.m_pendingRequest.swap(pendingRequestQueue);
+            Requests& request = queue.m_delayed.front();
+            bool result = AZStd::visit(
+                [this](auto&& args) -> bool
+                {
+                    return ProcessRequest(args);
+                },
+                request);
+            if (!result)
+            {
+                queue.m_delayed.emplace_back(AZStd::move(request));
+            }
+            queue.m_delayed.pop_front();
         }
 
-        if (!pendingRequestQueue.empty() || !queue.m_delayed.empty())
+        // Process newly added requests.
+        while (true)
         {
-            AZ::SerializeContext* serializeContext = nullptr;
-            AZ::ComponentApplicationBus::BroadcastResult(serializeContext, &AZ::ComponentApplicationBus::Events::GetSerializeContext);
-            AZ_Assert(serializeContext, "Failed to retrieve serialization context.");
-
-            // Only process the requests that are currently in this queue, not the ones that could be re-added if they still can't complete.
-            size_t delayedSize = queue.m_delayed.size();
-            for (size_t i = 0; i < delayedSize; ++i)
+            AZStd::queue<Requests> pendingRequestQueue;
             {
-                Requests& request = queue.m_delayed.front();
-                bool result = AZStd::visit([this, serializeContext](auto&& args) -> bool
-                    {
-                        return ProcessRequest(args, *serializeContext);
-                    }, request);
-                if (!result)
-                {
-                    queue.m_delayed.emplace_back(AZStd::move(request));
-                }
-                queue.m_delayed.pop_front();
+                AZStd::scoped_lock queueLock(queue.m_pendingRequestMutex);
+                queue.m_pendingRequest.swap(pendingRequestQueue);
             }
 
-            do
+            if (!pendingRequestQueue.empty())
             {
                 while (!pendingRequestQueue.empty())
                 {
                     Requests& request = pendingRequestQueue.front();
-                    bool result = AZStd::visit([this, serializeContext](auto&& args) -> bool
+                    bool result = AZStd::visit(
+                        [this](auto&& args) -> bool
                         {
-                            return ProcessRequest(args, *serializeContext);
-                        }, request);
+                            return ProcessRequest(args);
+                        },
+                        request);
                     if (!result)
                     {
                         queue.m_delayed.emplace_back(AZStd::move(request));
                     }
                     pendingRequestQueue.pop();
                 }
-
-                // Spawning entities can result in more entities being queued to spawn. Repeat spawning until the queue is
-                // empty to avoid a chain of entity spawning getting dragged out over multiple frames.
-                {
-                    AZStd::scoped_lock queueLock(queue.m_pendingRequestMutex);
-                    queue.m_pendingRequest.swap(pendingRequestQueue);
-                }
-            } while (!pendingRequestQueue.empty());
-        }
+            }
+            else
+            {
+                break;
+            }
+        };
 
         return queue.m_delayed.empty() ? CommandQueueStatus::NoCommandsLeft : CommandQueueStatus::HasCommandsLeft;
     }
@@ -250,24 +257,14 @@ namespace AzFramework
         }
     }
 
-    AZ::Entity* SpawnableEntitiesManager::SpawnSingleEntity(const AZ::Entity& entityTemplate, AZ::SerializeContext& serializeContext)
-    {
-        AZ::Entity* clone = serializeContext.CloneObject(&entityTemplate);
-        AZ_Assert(clone != nullptr, "Failed to clone spawnable entity.");
-        clone->SetId(AZ::Entity::MakeId());
-
-        GameEntityContextRequestBus::Broadcast(&GameEntityContextRequestBus::Events::AddGameEntity, clone);
-        return clone;
-    }
-
     AZ::Entity* SpawnableEntitiesManager::CloneSingleEntity(const AZ::Entity& entityTemplate,
-        EntityIdMap& templateToCloneEntityIdMap, AZ::SerializeContext& serializeContext)
+        EntityIdMap& templateToCloneMap, AZ::SerializeContext& serializeContext)
     {
-        return AZ::IdUtils::Remapper<AZ::EntityId>::CloneObjectAndGenerateNewIdsAndFixRefs(
-                &entityTemplate, templateToCloneEntityIdMap, &serializeContext);
+        return AZ::IdUtils::Remapper<AZ::EntityId, true>::CloneObjectAndGenerateNewIdsAndFixRefs(
+                &entityTemplate, templateToCloneMap, &serializeContext);
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(SpawnAllEntitiesCommand& request, AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(SpawnAllEntitiesCommand& request)
     {
         Ticket& ticket = *request.m_ticket;
         if (ticket.m_spawnable.IsReady() && request.m_requestId == ticket.m_currentRequestId)
@@ -291,13 +288,9 @@ namespace AzFramework
             spawnedEntityIndices.reserve(spawnedEntityIndices.size() + entitiesToSpawnSize);
             templateToCloneEntityIdMap.reserve(entitiesToSpawnSize);
 
-            // Mark all indices as spawned
             for (size_t i = 0; i < entitiesToSpawnSize; ++i)
             {
-                const AZ::Entity& entityTemplate = *entitiesToSpawn[i];
-
-                AZ::Entity* clone = CloneSingleEntity(entityTemplate, templateToCloneEntityIdMap, serializeContext);
-
+                AZ::Entity* clone = CloneSingleEntity(*entitiesToSpawn[i], templateToCloneEntityIdMap, *request.m_serializeContext);
                 AZ_Assert(clone != nullptr, "Failed to clone spawnable entity.");
 
                 spawnedEntities.emplace_back(clone);
@@ -305,16 +298,8 @@ namespace AzFramework
             }
 
             // loadAll is true if every entity has been spawned only once
-            if (spawnedEntities.size() == entitiesToSpawnSize)
-            {
-                ticket.m_loadAll = true;
-            }
-            else
-            {
-                // Case where there were already spawns from a previous request
-                ticket.m_loadAll = false;
-            }
-
+            ticket.m_loadAll = (spawnedEntities.size() == entitiesToSpawnSize);
+            
             // Let other systems know about newly spawned entities for any pre-processing before adding to the scene/game context.
             if (request.m_preInsertionCallback)
             {
@@ -323,11 +308,10 @@ namespace AzFramework
             }
 
             // Add to the game context, now the entities are active
-            AZStd::for_each(ticket.m_spawnedEntities.begin() + spawnedEntitiesInitialCount, ticket.m_spawnedEntities.end(),
-                [](AZ::Entity* entity)
+            for (auto it = ticket.m_spawnedEntities.begin() + spawnedEntitiesInitialCount; it != ticket.m_spawnedEntities.end(); ++it)
             {
-                GameEntityContextRequestBus::Broadcast(&GameEntityContextRequestBus::Events::AddGameEntity, entity);
-            });
+                GameEntityContextRequestBus::Broadcast(&GameEntityContextRequestBus::Events::AddGameEntity, *it);
+            }
 
             // Let other systems know about newly spawned entities for any post-processing after adding to the scene/game context.
             if (request.m_completionCallback)
@@ -347,21 +331,41 @@ namespace AzFramework
         }
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(SpawnEntitiesCommand& request, AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(SpawnEntitiesCommand& request)
     {
         Ticket& ticket = *request.m_ticket;
         if (ticket.m_spawnable.IsReady() && request.m_requestId == ticket.m_currentRequestId)
         {
             AZStd::vector<AZ::Entity*>& spawnedEntities = ticket.m_spawnedEntities;
             AZStd::vector<size_t>& spawnedEntityIndices = ticket.m_spawnedEntityIndices;
+            AZ_Assert(
+                spawnedEntities.size() == spawnedEntityIndices.size(),
+                "The indices for the spawned entities has gone out of sync with the entities.");
 
-            // Keep track how many entities there were in the array initially
+            // Keep track of how many entities there were in the array initially
             size_t spawnedEntitiesInitialCount = spawnedEntities.size();
 
             // These are 'template' entities we'll be cloning from
             const Spawnable::EntityList& entitiesToSpawn = ticket.m_spawnable->GetEntities();
             size_t entitiesToSpawnSize = request.m_entityIndices.size();
 
+            // Reconstruct the template to entity mapping.
+            EntityIdMap templateToCloneEntityIdMap;
+            if (!request.m_referencePreviouslySpawnedEntities)
+            {
+                templateToCloneEntityIdMap.reserve(entitiesToSpawnSize);
+            }
+            else
+            {
+                templateToCloneEntityIdMap.reserve(spawnedEntitiesInitialCount + entitiesToSpawnSize);
+                SpawnableConstIndexEntityContainerView indexEntityView(
+                    spawnedEntities.begin(), spawnedEntityIndices.begin(), spawnedEntities.size());
+                for (auto& entry : indexEntityView)
+                {
+                    templateToCloneEntityIdMap.insert_or_assign(entitiesToSpawn[entry.GetIndex()]->GetId(), entry.GetEntity()->GetId());
+                }
+            }
+
             spawnedEntities.reserve(spawnedEntities.size() + entitiesToSpawnSize);
             spawnedEntityIndices.reserve(spawnedEntityIndices.size() + entitiesToSpawnSize);
 
@@ -369,15 +373,11 @@ namespace AzFramework
             {
                 if (index < entitiesToSpawn.size())
                 {
-                    const AZ::Entity& entityTemplate = *entitiesToSpawn[index];
-
-                    AZ::Entity* clone = serializeContext.CloneObject(&entityTemplate);
+                    AZ::Entity* clone = CloneSingleEntity(*entitiesToSpawn[index], templateToCloneEntityIdMap, *request.m_serializeContext);
                     AZ_Assert(clone != nullptr, "Failed to clone spawnable entity.");
-                    clone->SetId(AZ::Entity::MakeId());
 
                     spawnedEntities.push_back(clone);
                     spawnedEntityIndices.push_back(index);
-
                 }
             }
             ticket.m_loadAll = false;
@@ -390,11 +390,10 @@ namespace AzFramework
             }
 
             // Add to the game context, now the entities are active
-            AZStd::for_each(ticket.m_spawnedEntities.begin() + spawnedEntitiesInitialCount, ticket.m_spawnedEntities.end(),
-                [](AZ::Entity* entity)
+            for (auto it = ticket.m_spawnedEntities.begin() + spawnedEntitiesInitialCount; it != ticket.m_spawnedEntities.end(); ++it)
             {
-                GameEntityContextRequestBus::Broadcast(&GameEntityContextRequestBus::Events::AddGameEntity, entity);
-            });
+                GameEntityContextRequestBus::Broadcast(&GameEntityContextRequestBus::Events::AddGameEntity, *it);
+            }
 
             if (request.m_completionCallback)
             {
@@ -413,8 +412,7 @@ namespace AzFramework
         }
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(DespawnAllEntitiesCommand& request,
-        [[maybe_unused]] AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(DespawnAllEntitiesCommand& request)
     {
         Ticket& ticket = *request.m_ticket;
         if (request.m_requestId == ticket.m_currentRequestId)
@@ -447,7 +445,7 @@ namespace AzFramework
         }
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(ReloadSpawnableCommand& request, AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(ReloadSpawnableCommand& request)
     {
         Ticket& ticket = *request.m_ticket;
         AZ_Assert(ticket.m_spawnable.GetId() == request.m_spawnable.GetId(),
@@ -470,39 +468,43 @@ namespace AzFramework
             // Rebuild the list of entities.
             ticket.m_spawnedEntities.clear();
             const Spawnable::EntityList& entities = request.m_spawnable->GetEntities();
+
+            // Map keeps track of ids from template (spawnable) to clone (instance)
+            // Allowing patch ups of fields referring to entityIds outside of a given entity
+            EntityIdMap templateToCloneEntityIdMap;
+
             if (ticket.m_loadAll)
             {
                 // The new spawnable may have a different number of entities and since the intent of the user was
-                // to load every, simply start over.
+                // to spawn every entity, simply start over.
                 ticket.m_spawnedEntityIndices.clear();
-
                 size_t entitiesToSpawnSize = entities.size();
-
-                // Map keeps track of ids from template (spawnable) to clone (instance)
-                // Allowing patch ups of fields referring to entityIds outside of a given entity
-                EntityIdMap templateToCloneEntityIdMap;
                 templateToCloneEntityIdMap.reserve(entitiesToSpawnSize);
 
-                // Mark all indices as spawned
                 for (size_t i = 0; i < entitiesToSpawnSize; ++i)
                 {
-                    const AZ::Entity& entityTemplate = *entities[i];
-
-                    AZ::Entity* clone = CloneSingleEntity(entityTemplate, templateToCloneEntityIdMap, serializeContext);
-
+                    AZ::Entity* clone = CloneSingleEntity(*entities[i], templateToCloneEntityIdMap, *request.m_serializeContext);
                     AZ_Assert(clone != nullptr, "Failed to clone spawnable entity.");
 
-                    ticket.m_spawnedEntities.emplace_back(clone);
+                    ticket.m_spawnedEntities.push_back(clone);
                     ticket.m_spawnedEntityIndices.push_back(i);
                 }
             }
             else
             {
                 size_t entitiesSize = entities.size();
+                templateToCloneEntityIdMap.reserve(entitiesSize);
                 for (size_t index : ticket.m_spawnedEntityIndices)
                 {
-                    ticket.m_spawnedEntities.push_back(
-                        index < entitiesSize ? SpawnSingleEntity(*entities[index], serializeContext) : nullptr);
+                    // It's possible for the new spawnable to have a different number of entities, so guard against this.
+                    // It's also possible that the entities have moved within the spawnable to a new index. This can't be
+                    // detected and will result in the incorrect entities being spawned.
+                    if (index < entitiesSize)
+                    {
+                        AZ::Entity* clone = CloneSingleEntity(*entities[index], templateToCloneEntityIdMap, *request.m_serializeContext);
+                        AZ_Assert(clone != nullptr, "Failed to clone spawnable entity.");
+                        ticket.m_spawnedEntities.push_back(clone);
+                    }
                 }
             }
             ticket.m_spawnable = AZStd::move(request.m_spawnable);
@@ -525,7 +527,7 @@ namespace AzFramework
         }
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(ListEntitiesCommand& request, [[maybe_unused]] AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(ListEntitiesCommand& request)
     {
         Ticket& ticket = *request.m_ticket;
         if (request.m_requestId == ticket.m_currentRequestId)
@@ -541,7 +543,7 @@ namespace AzFramework
         }
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(ListIndicesEntitiesCommand& request, [[maybe_unused]] AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(ListIndicesEntitiesCommand& request)
     {
         Ticket& ticket = *request.m_ticket;
         if (request.m_requestId == ticket.m_currentRequestId)
@@ -560,7 +562,7 @@ namespace AzFramework
         }
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(ClaimEntitiesCommand& request, [[maybe_unused]] AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(ClaimEntitiesCommand& request)
     {
         Ticket& ticket = *request.m_ticket;
         if (request.m_requestId == ticket.m_currentRequestId)
@@ -580,7 +582,7 @@ namespace AzFramework
         }
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(BarrierCommand& request, [[maybe_unused]] AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(BarrierCommand& request)
     {
         Ticket& ticket = *request.m_ticket;
         if (request.m_requestId == ticket.m_currentRequestId)
@@ -599,7 +601,7 @@ namespace AzFramework
         }
     }
 
-    bool SpawnableEntitiesManager::ProcessRequest(DestroyTicketCommand& request, [[maybe_unused]] AZ::SerializeContext& serializeContext)
+    bool SpawnableEntitiesManager::ProcessRequest(DestroyTicketCommand& request)
     {
         if (request.m_requestId == request.m_ticket->m_currentRequestId)
         {

Code/Framework/AzFramework/AzFramework/Spawnable/SpawnableEntitiesManager.h

@@ -37,7 +37,7 @@ namespace AzFramework
         AZ_CLASS_ALLOCATOR(SpawnableEntitiesManager, AZ::SystemAllocator, 0);
 
         using EntityIdMap = AZStd::unordered_map<AZ::EntityId, AZ::EntityId>;
-
+        
         enum class CommandQueueStatus : bool
         {
             HasCommandsLeft,
@@ -57,26 +57,21 @@ namespace AzFramework
         // The following functions are thread safe
         //
 
-        void SpawnAllEntities(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, EntityPreInsertionCallback preInsertionCallback = {},
-            EntitySpawnCallback completionCallback = {}) override;
+        void SpawnAllEntities(EntitySpawnTicket& ticket, SpawnAllEntitiesOptionalArgs optionalArgs = {}) override;
         void SpawnEntities(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, AZStd::vector<size_t> entityIndices,
-            EntityPreInsertionCallback preInsertionCallback = {},
-            EntitySpawnCallback completionCallback = {}) override;
-        void DespawnAllEntities(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, EntityDespawnCallback completionCallback = {}) override;
-
+            EntitySpawnTicket& ticket, AZStd::vector<size_t> entityIndices, SpawnEntitiesOptionalArgs optionalArgs = {}) override;
+        void DespawnAllEntities(EntitySpawnTicket& ticket, DespawnAllEntitiesOptionalArgs optionalArgs = {}) override;
         void ReloadSpawnable(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, AZ::Data::Asset<Spawnable> spawnable,
-            ReloadSpawnableCallback completionCallback = {}) override;
+            EntitySpawnTicket& ticket, AZ::Data::Asset<Spawnable> spawnable, ReloadSpawnableOptionalArgs optionalArgs = {}) override;
 
-        void ListEntities(EntitySpawnTicket& ticket, SpawnablePriority priority, ListEntitiesCallback listCallback) override;
+        void ListEntities(
+            EntitySpawnTicket& ticket, ListEntitiesCallback listCallback, ListEntitiesOptionalArgs optionalArgs = {}) override;
         void ListIndicesAndEntities(
-            EntitySpawnTicket& ticket, SpawnablePriority priority, ListIndicesEntitiesCallback listCallback) override;
-        void ClaimEntities(EntitySpawnTicket& ticket, SpawnablePriority priority, ClaimEntitiesCallback listCallback) override;
+            EntitySpawnTicket& ticket, ListIndicesEntitiesCallback listCallback, ListEntitiesOptionalArgs optionalArgs = {}) override;
+        void ClaimEntities(
+            EntitySpawnTicket& ticket, ClaimEntitiesCallback listCallback, ClaimEntitiesOptionalArgs optionalArgs = {}) override;
 
-        void Barrier(EntitySpawnTicket& spawnInfo, SpawnablePriority priority, BarrierCallback completionCallback) override;
+        void Barrier(EntitySpawnTicket& spawnInfo, BarrierCallback completionCallback, BarrierOptionalArgs optionalArgs = {}) override;
 
         void AddOnSpawnedHandler(AZ::Event<AZ::Data::Asset<Spawnable>>::Handler& handler) override;
         void AddOnDespawnedHandler(AZ::Event<AZ::Data::Asset<Spawnable>>::Handler& handler) override;
@@ -105,6 +100,7 @@ namespace AzFramework
         {
             EntitySpawnCallback m_completionCallback;
             EntityPreInsertionCallback m_preInsertionCallback;
+            AZ::SerializeContext* m_serializeContext;
             Ticket* m_ticket;
             EntitySpawnTicket::Id m_ticketId;
             uint32_t m_requestId;
@@ -114,9 +110,11 @@ namespace AzFramework
             AZStd::vector<size_t> m_entityIndices;
             EntitySpawnCallback m_completionCallback;
             EntityPreInsertionCallback m_preInsertionCallback;
+            AZ::SerializeContext* m_serializeContext;
             Ticket* m_ticket;
             EntitySpawnTicket::Id m_ticketId;
             uint32_t m_requestId;
+            bool m_referencePreviouslySpawnedEntities;
         };
         struct DespawnAllEntitiesCommand
         {
@@ -129,6 +127,7 @@ namespace AzFramework
         {
             AZ::Data::Asset<Spawnable> m_spawnable;
             ReloadSpawnableCallback m_completionCallback;
+            AZ::SerializeContext* m_serializeContext;
             Ticket* m_ticket;
             EntitySpawnTicket::Id m_ticketId;
             uint32_t m_requestId;
@@ -185,21 +184,18 @@ namespace AzFramework
 
         CommandQueueStatus ProcessQueue(Queue& queue);
 
-        AZ::Entity* SpawnSingleEntity(const AZ::Entity& entityTemplate,
-            AZ::SerializeContext& serializeContext);
-
-        AZ::Entity* CloneSingleEntity(const AZ::Entity& entityTemplate,
-            EntityIdMap& templateToCloneEntityIdMap, AZ::SerializeContext& serializeContext);
-
-        bool ProcessRequest(SpawnAllEntitiesCommand& request, AZ::SerializeContext& serializeContext);
-        bool ProcessRequest(SpawnEntitiesCommand& request, AZ::SerializeContext& serializeContext);
-        bool ProcessRequest(DespawnAllEntitiesCommand& request, AZ::SerializeContext& serializeContext);
-        bool ProcessRequest(ReloadSpawnableCommand& request, AZ::SerializeContext& serializeContext);
-        bool ProcessRequest(ListEntitiesCommand& request, AZ::SerializeContext& serializeContext);
-        bool ProcessRequest(ListIndicesEntitiesCommand& request, AZ::SerializeContext& serializeContext);
-        bool ProcessRequest(ClaimEntitiesCommand& request, AZ::SerializeContext& serializeContext);
-        bool ProcessRequest(BarrierCommand& request, AZ::SerializeContext& serializeContext);
-        bool ProcessRequest(DestroyTicketCommand& request, AZ::SerializeContext& serializeContext);
+        AZ::Entity* CloneSingleEntity(
+            const AZ::Entity& entityTemplate, EntityIdMap& templateToCloneMap, AZ::SerializeContext& serializeContext);
+        
+        bool ProcessRequest(SpawnAllEntitiesCommand& request);
+        bool ProcessRequest(SpawnEntitiesCommand& request);
+        bool ProcessRequest(DespawnAllEntitiesCommand& request);
+        bool ProcessRequest(ReloadSpawnableCommand& request);
+        bool ProcessRequest(ListEntitiesCommand& request);
+        bool ProcessRequest(ListIndicesEntitiesCommand& request);
+        bool ProcessRequest(ClaimEntitiesCommand& request);
+        bool ProcessRequest(BarrierCommand& request);
+        bool ProcessRequest(DestroyTicketCommand& request);
 
         Queue m_highPriorityQueue;
         Queue m_regularPriorityQueue;
@@ -207,6 +203,7 @@ namespace AzFramework
         AZ::Event<AZ::Data::Asset<Spawnable>> m_onSpawnedEvent;
         AZ::Event<AZ::Data::Asset<Spawnable>> m_onDespawnedEvent;
 
+        AZ::SerializeContext* m_defaultSerializeContext { nullptr };
         //! The threshold used to determine if a request goes in the regular (if bigger than the value) or high priority queue (if smaller
         //! or equal to this value). The starting value of 64 is chosen as it's between default values SpawnablePriority_High and
         //! SpawnablePriority_Default which gives users a bit of room to fine tune the priorities as this value can be configured

Code/Framework/AzFramework/AzFramework/Viewport/ViewportScreen.cpp

@@ -128,12 +128,12 @@ namespace AzFramework
             worldPosition, CameraView(cameraState), CameraProjection(cameraState), cameraState.m_viewportSize);
     }
 
-    AZ::Vector3 ScreenToWorld(
-        const ScreenPoint& screenPosition, const AZ::Matrix4x4& inverseCameraView,
-        const AZ::Matrix4x4& inverseCameraProjection, const AZ::Vector2& viewportSize)
+    AZ::Vector3 ScreenNDCToWorld(
+        const AZ::Vector2& normalizedScreenPosition, const AZ::Matrix4x4& inverseCameraView,
+        const AZ::Matrix4x4& inverseCameraProjection)
     {
         // convert screen space coordinates from <0, 1> to <-1,1> range
-        const auto ndcPosition = NDCFromScreenPoint(screenPosition, viewportSize) * 2.0f - AZ::Vector2::CreateOne();
+        const auto ndcPosition = normalizedScreenPosition * 2.0f - AZ::Vector2::CreateOne();
 
         // transform ndc space position to clip space
         const auto clipSpacePosition = inverseCameraProjection * Vector2ToVector4(ndcPosition, -1.0f, 1.0f);
@@ -145,6 +145,15 @@ namespace AzFramework
         return worldPosition;
     }
 
+    AZ::Vector3 ScreenToWorld(
+        const ScreenPoint& screenPosition, const AZ::Matrix4x4& inverseCameraView,
+        const AZ::Matrix4x4& inverseCameraProjection, const AZ::Vector2& viewportSize)
+    {
+        const auto normalizedScreenPosition = NDCFromScreenPoint(screenPosition, viewportSize);
+
+        return ScreenNDCToWorld(normalizedScreenPosition, inverseCameraView, inverseCameraProjection);
+    }
+
     AZ::Vector3 ScreenToWorld(const ScreenPoint& screenPosition, const CameraState& cameraState)
     {
         return ScreenToWorld(

Code/Framework/AzFramework/AzFramework/Viewport/ViewportScreen.h

@@ -42,7 +42,7 @@ namespace AzFramework
         const AZ::Vector3& worldPosition, const AZ::Matrix4x4& cameraView, const AZ::Matrix4x4& cameraProjection,
         const AZ::Vector2& viewportSize);
 
-    //! Unprojects a position in screen space to world space.
+    //! Unprojects a position in screen space pixel coordinates to world space.
     //! Note: The position returned will be on the near clip plane of the camera in world space.
     AZ::Vector3 ScreenToWorld(const ScreenPoint& screenPosition, const CameraState& cameraState);
 
@@ -52,6 +52,12 @@ namespace AzFramework
         const ScreenPoint& screenPosition, const AZ::Matrix4x4& inverseCameraView,
         const AZ::Matrix4x4& inverseCameraProjection, const AZ::Vector2& viewportSize);
 
+    //! Unprojects a position in screen space normalized device coordinates to world space.
+    //! Note: The position returned will be on the near clip plane of the camera in world space.
+    AZ::Vector3 ScreenNDCToWorld(
+        const AZ::Vector2& ndcPosition, const AZ::Matrix4x4& inverseCameraView,
+        const AZ::Matrix4x4& inverseCameraProjection);
+
     //! Returns the camera projection for the current camera state.
     AZ::Matrix4x4 CameraProjection(const CameraState& cameraState);
 

Code/Framework/AzFramework/Platform/Windows/AzFramework/Windowing/NativeWindow_Windows.cpp

@@ -353,6 +353,7 @@ namespace AzFramework
 
         // Get the dimensions of the display device on which the window is currently displayed.
         MONITORINFO monitorInfo;
+        memset(&monitorInfo, 0, sizeof(MONITORINFO)); // C4701 potentially uninitialized local variable 'monitorInfo' used
         monitorInfo.cbSize = sizeof(MONITORINFO);
         const BOOL success = monitor ? GetMonitorInfo(monitor, &monitorInfo) : FALSE;
         if (!success)

Code/Framework/AzManipulatorTestFramework/Include/AzManipulatorTestFramework/AzManipulatorTestFrameworkUtils.h

@@ -12,17 +12,22 @@
 
 #pragma once
 
-#include <AzToolsFramework/Manipulators/ManipulatorManager.h>
-#include <AzToolsFramework/Manipulators/ManipulatorBus.h>
 #include <AzToolsFramework/Manipulators/LinearManipulator.h>
+#include <AzToolsFramework/Manipulators/ManipulatorBus.h>
+#include <AzToolsFramework/Manipulators/ManipulatorManager.h>
+#include <AzToolsFramework/Manipulators/PlanarManipulator.h>
 
 namespace AzManipulatorTestFramework
 {
-    //! Create a linear manipulator with a unit sphere bounds.
+    //! Create a linear manipulator with a unit sphere bound.
     AZStd::shared_ptr<AzToolsFramework::LinearManipulator> CreateLinearManipulator(
-        const AzToolsFramework::ManipulatorManagerId manipulatorManagerId,
-        const AZ::Vector3& position = AZ::Vector3::CreateZero(),
-        const float radius = 1.0f);
+        const AzToolsFramework::ManipulatorManagerId manipulatorManagerId, const AZ::Vector3& position = AZ::Vector3::CreateZero(),
+        float radius = 1.0f);
+
+    //! Create a planar manipulator with a unit sphere bound.
+    AZStd::shared_ptr<AzToolsFramework::PlanarManipulator> CreatePlanarManipulator(
+        const AzToolsFramework::ManipulatorManagerId manipulatorManagerId, const AZ::Vector3& position = AZ::Vector3::CreateZero(),
+        float radius = 1.0f);
 
     //! Create a mouse pick from the specified ray and screen point.
     AzToolsFramework::ViewportInteraction::MousePick CreateMousePick(
@@ -34,14 +39,12 @@ namespace AzManipulatorTestFramework
 
     //! Create a mouse interaction from the specified pick, buttons, interaction id and keyboard modifiers.
     AzToolsFramework::ViewportInteraction::MouseInteraction CreateMouseInteraction(
-        const AzToolsFramework::ViewportInteraction::MousePick& mousePick,
-        AzToolsFramework::ViewportInteraction::MouseButtons buttons,
+        const AzToolsFramework::ViewportInteraction::MousePick& mousePick, AzToolsFramework::ViewportInteraction::MouseButtons buttons,
         AzToolsFramework::ViewportInteraction::InteractionId interactionId,
         AzToolsFramework::ViewportInteraction::KeyboardModifiers modifiers);
 
     //! Create a mouse buttons from the specified mouse button.
-    AzToolsFramework::ViewportInteraction::MouseButtons CreateMouseButtons(
-        AzToolsFramework::ViewportInteraction::MouseButton button);
+    AzToolsFramework::ViewportInteraction::MouseButtons CreateMouseButtons(AzToolsFramework::ViewportInteraction::MouseButton button);
 
     //! Create a mouse interaction event from the specified interaction and event.
     AzToolsFramework::ViewportInteraction::MouseInteractionEvent CreateMouseInteractionEvent(
@@ -61,5 +64,5 @@ namespace AzManipulatorTestFramework
     AzFramework::ScreenPoint GetCameraStateViewportCenter(const AzFramework::CameraState& cameraState);
 
     //! Default viewport size (1080p) in 16:9 aspect ratio.
-    const auto DefaultViewportSize = AZ::Vector2(1920.0f, 1080.0f);
+    inline const auto DefaultViewportSize = AZ::Vector2(1920.0f, 1080.0f);
 } // namespace AzManipulatorTestFramework

Code/Framework/AzManipulatorTestFramework/Source/AzManipulatorTestFrameworkUtils.cpp

@@ -14,7 +14,6 @@
 #include <AzFramework/Viewport/ViewportScreen.h>
 #include <AzManipulatorTestFramework/AzManipulatorTestFrameworkUtils.h>
 #include <AzToolsFramework/ViewportSelection/EditorInteractionSystemViewportSelectionRequestBus.h>
-#include <AzToolsFramework/ViewportSelection/EditorInteractionSystemViewportSelectionRequestBus.h>
 #include <AzToolsFramework/ViewportSelection/EditorTransformComponentSelectionRequestBus.h>
 
 namespace AzManipulatorTestFramework
@@ -28,22 +27,21 @@ namespace AzManipulatorTestFramework
     using MouseEvent = AzToolsFramework::ViewportInteraction::MouseEvent;
     using MousePick = AzToolsFramework::ViewportInteraction::MousePick;
 
-    AZStd::shared_ptr<AzToolsFramework::LinearManipulator> CreateLinearManipulator(
-        const AzToolsFramework::ManipulatorManagerId manipulatorManagerId,
-        const AZ::Vector3& position,
-        const float radius)
+    // create a default sphere view for a manipulator for simple intersection
+    template<typename Manipulator>
+    void SetupManipulatorView(
+        AZStd::shared_ptr<Manipulator> manipulator, const AzToolsFramework::ManipulatorManagerId manipulatorManagerId,
+        const AZ::Vector3& position, const float radius)
     {
-        auto manipulator = AzToolsFramework::LinearManipulator::MakeShared(AZ::Transform::CreateIdentity());
-        manipulator->SetLocalPosition(position);
-
         // unit sphere view
         auto sphereView = AzToolsFramework::CreateManipulatorViewSphere(
             AZ::Colors::Red, radius,
-            [](const MouseInteraction& /*mouseInteraction*/, const bool /*mouseOver*/,
-                const AZ::Color& defaultColor)
-        {
-            return defaultColor;
-        }, true);
+            []([[maybe_unused]] const MouseInteraction& mouseInteraction, [[maybe_unused]] const bool mouseOver,
+               const AZ::Color& defaultColor)
+            {
+                return defaultColor;
+            },
+            true);
 
         // unit sphere bound
         AzToolsFramework::Picking::BoundShapeSphere sphereBound;
@@ -62,6 +60,26 @@ namespace AzManipulatorTestFramework
         // this would occur internally when the manipulator is drawn but we must do manually here to ensure that the
         // bounds will always be valid upon instantiation
         view->RefreshBound(manipulatorManagerId, manipulator->GetManipulatorId(), sphereBound);
+    }
+
+    AZStd::shared_ptr<AzToolsFramework::LinearManipulator> CreateLinearManipulator(
+        const AzToolsFramework::ManipulatorManagerId manipulatorManagerId, const AZ::Vector3& position, const float radius)
+    {
+        auto manipulator = AzToolsFramework::LinearManipulator::MakeShared(AZ::Transform::CreateIdentity());
+        manipulator->SetLocalPosition(position);
+
+        SetupManipulatorView(manipulator, manipulatorManagerId, position, radius);
+
+        return manipulator;
+    }
+
+    AZStd::shared_ptr<AzToolsFramework::PlanarManipulator> CreatePlanarManipulator(
+        const AzToolsFramework::ManipulatorManagerId manipulatorManagerId, const AZ::Vector3& position, const float radius)
+    {
+        auto manipulator = AzToolsFramework::PlanarManipulator::MakeShared(AZ::Transform::CreateIdentity());
+        manipulator->SetLocalPosition(position);
+
+        SetupManipulatorView(manipulator, manipulatorManagerId, position, radius);
 
         return manipulator;
     }
@@ -104,8 +122,7 @@ namespace AzManipulatorTestFramework
         return buttons;
     }
 
-    MouseInteractionEvent CreateMouseInteractionEvent(
-        const MouseInteraction& mouseInteraction, MouseEvent event)
+    MouseInteractionEvent CreateMouseInteractionEvent(const MouseInteraction& mouseInteraction, MouseEvent event)
     {
         return MouseInteractionEvent(mouseInteraction, event);
     }
@@ -114,8 +131,7 @@ namespace AzManipulatorTestFramework
     {
         AzToolsFramework::EditorInteractionSystemViewportSelectionRequestBus::Event(
             AzToolsFramework::GetEntityContextId(),
-            &AzToolsFramework::ViewportInteraction::InternalMouseViewportRequests::InternalHandleAllMouseInteractions,
-            event);
+            &AzToolsFramework::ViewportInteraction::InternalMouseViewportRequests::InternalHandleAllMouseInteractions, event);
     }
 
     AzFramework::CameraState SetCameraStatePosition(const AZ::Vector3& position, AzFramework::CameraState& cameraState)
@@ -133,9 +149,7 @@ namespace AzManipulatorTestFramework
 
     AzFramework::ScreenPoint GetCameraStateViewportCenter(const AzFramework::CameraState& cameraState)
     {
-        return {
-            aznumeric_cast<int>(cameraState.m_viewportSize.GetX() / 2.f),
-            aznumeric_cast<int>(cameraState.m_viewportSize.GetY() / 2.f)
-        };
+        return { aznumeric_cast<int>(cameraState.m_viewportSize.GetX() / 2.f),
+                 aznumeric_cast<int>(cameraState.m_viewportSize.GetY() / 2.f) };
     }
-} // namespace UnitTest
+} // namespace AzManipulatorTestFramework

Code/Framework/AzManipulatorTestFramework/Tests/GridSnappingTest.cpp

@@ -10,52 +10,55 @@
  *
  */
 
+#include "AzManipulatorTestFrameworkTestFixtures.h"
+
 #include <AzCore/std/smart_ptr/unique_ptr.h>
 #include <AzFramework/Viewport/ViewportScreen.h>
 #include <AzManipulatorTestFramework/AzManipulatorTestFramework.h>
-#include "AzManipulatorTestFrameworkTestFixtures.h"
-#include <AzManipulatorTestFramework/DirectManipulatorViewportInteraction.h>
-#include <AzManipulatorTestFramework/IndirectManipulatorViewportInteraction.h>
-#include <AzManipulatorTestFramework/ImmediateModeActionDispatcher.h>
 #include <AzManipulatorTestFramework/AzManipulatorTestFrameworkUtils.h>
+#include <AzManipulatorTestFramework/DirectManipulatorViewportInteraction.h>
+#include <AzManipulatorTestFramework/ImmediateModeActionDispatcher.h>
+#include <AzManipulatorTestFramework/IndirectManipulatorViewportInteraction.h>
+#include <AzToolsFramework/Manipulators/LinearManipulator.h>
+#include <AzToolsFramework/Manipulators/PlanarManipulator.h>
 #include <AzToolsFramework/ViewportSelection/EditorSelectionUtil.h>
+#include <AZTestShared/Math/MathTestHelpers.h>
 
 namespace UnitTest
 {
-    class GridSnappingFixture
-        : public ToolsApplicationFixture
+    class GridSnappingFixture : public ToolsApplicationFixture
     {
     public:
         GridSnappingFixture()
             : m_viewportManipulatorInteraction(AZStd::make_unique<AzManipulatorTestFramework::DirectCallManipulatorViewportInteraction>())
-            , m_actionDispatcher(AZStd::make_unique<AzManipulatorTestFramework::ImmediateModeActionDispatcher>(*m_viewportManipulatorInteraction))
-            , m_linearManipulator(
-                AzManipulatorTestFramework::CreateLinearManipulator(
-                    m_viewportManipulatorInteraction->GetManipulatorManager().GetId(),
-                    /*position=*/AZ::Vector3(0.0f, 50.0f, 0.0f),
-                    /*radius=*/m_boundsRadius))
-        {}
+            , m_actionDispatcher(
+                  AZStd::make_unique<AzManipulatorTestFramework::ImmediateModeActionDispatcher>(*m_viewportManipulatorInteraction))
+        {
+        }
 
     protected:
         void SetUpEditorFixtureImpl() override
         {
-            m_cameraState = AzFramework::CreateIdentityDefaultCamera(
-                AZ::Vector3::CreateZero(), AzManipulatorTestFramework::DefaultViewportSize);
+            m_cameraState =
+                AzFramework::CreateIdentityDefaultCamera(AZ::Vector3::CreateZero(), AzManipulatorTestFramework::DefaultViewportSize);
         }
 
     public:
-
         const float m_boundsRadius = 1.0f;
         AZStd::unique_ptr<AzManipulatorTestFramework::ManipulatorViewportInteraction> m_viewportManipulatorInteraction;
         AZStd::unique_ptr<AzManipulatorTestFramework::ImmediateModeActionDispatcher> m_actionDispatcher;
-        AZStd::shared_ptr<AzToolsFramework::LinearManipulator> m_linearManipulator;
         AzFramework::CameraState m_cameraState;
     };
 
     TEST_F(GridSnappingFixture, MouseDownWithSnappingEnabledSnapsToClosestGridSize)
     {
+        AZStd::shared_ptr<AzToolsFramework::LinearManipulator> linearManipulator(AzManipulatorTestFramework::CreateLinearManipulator(
+            m_viewportManipulatorInteraction->GetManipulatorManager().GetId(),
+            /*position=*/AZ::Vector3(0.0f, 50.0f, 0.0f),
+            /*radius=*/m_boundsRadius));
+
         // the initial starting position of the manipulator (in front of the camera)
-        const auto initialPositionWorld = m_linearManipulator->GetLocalPosition();
+        const auto initialPositionWorld = linearManipulator->GetLocalPosition();
         // where the manipulator should end up (in front and to the left of the camera)
         const auto finalPositionWorld = AZ::Vector3(-10.0f, 50.0f, 0.0f);
         // perspective scale factor for manipulator distance to camera
@@ -66,21 +69,18 @@ namespace UnitTest
         // adjusted final world position taking into account the manipulator position relative to the camera
         const auto finalPositionWorldAdjusted = finalPositionWorld - (vectorToInitialPositionWorld * scaledRadiusBound);
         // calculate the position in screen space of the initial position of the manipulator
-        const auto initialPositionScreen =
-            AzFramework::WorldToScreen(initialPositionWorld, m_cameraState);
+        const auto initialPositionScreen = AzFramework::WorldToScreen(initialPositionWorld, m_cameraState);
         // calculate the position in screen space of the final position of the manipulator
         const auto finalPositionScreen = AzFramework::WorldToScreen(finalPositionWorldAdjusted, m_cameraState);
 
         // callback to update the manipulator's current position
-        m_linearManipulator->InstallMouseMoveCallback(
-            [this](const AzToolsFramework::LinearManipulator::Action& action)
-        {
-            auto pos = action.LocalPosition();
-            m_linearManipulator->SetLocalPosition(pos);
-        });
+        linearManipulator->InstallMouseMoveCallback(
+            [this, linearManipulator](const AzToolsFramework::LinearManipulator::Action& action)
+            {
+                linearManipulator->SetLocalPosition(action.LocalPosition());
+            });
 
-        m_actionDispatcher
-            ->EnableSnapToGrid()
+        m_actionDispatcher->EnableSnapToGrid()
             ->GridSize(5.0f)
             ->CameraState(m_cameraState)
             ->MousePosition(initialPositionScreen)
@@ -89,7 +89,67 @@ namespace UnitTest
             ->MousePosition(finalPositionScreen)
             ->MouseLButtonUp()
             ->ExpectManipulatorNotBeingInteracted()
-            ->ExpectTrue(m_linearManipulator->GetLocalPosition().IsClose(finalPositionWorld, 0.01f))
-            ;
+            ->ExpectTrue(linearManipulator->GetLocalPosition().IsClose(finalPositionWorld, 0.01f));
+    }
+
+    template<typename Manipulator>
+    void ValidateManipulatorSnappingBehavior(
+        AZStd::shared_ptr<Manipulator> manipulator, AzManipulatorTestFramework::ImmediateModeActionDispatcher* actionDispatcher,
+        const AzFramework::CameraState& cameraState)
+    {
+        manipulator->SetLocalOrientation(AZ::Quaternion::CreateFromEulerAnglesDegrees(AZ::Vector3(180.0f, 0.0f, 135.0f)));
+
+        // the initial starting position of the manipulator (in front of the camera)
+        const auto initialPositionWorld = manipulator->GetLocalPosition() + AZ::Vector3::CreateAxisX(0.15f);
+        // where the manipulator should end up (unmoved)
+        const auto finalPositionWorld = manipulator->GetLocalPosition();
+        // where we should move the mouse to
+        const auto attemptPositionWorld = manipulator->GetLocalPosition() + AZ::Vector3::CreateAxisX(0.35f);
+        // calculate the position in screen space of the initial position of the manipulator
+        const auto initialPositionScreen = AzFramework::WorldToScreen(initialPositionWorld, cameraState);
+        // calculate the position in screen space of the final position of the manipulator
+        const auto attemptPositionScreen = AzFramework::WorldToScreen(attemptPositionWorld, cameraState);
+
+        // callback to update the manipulator's current position
+        manipulator->InstallMouseMoveCallback(
+            [manipulator](const typename Manipulator::Action& action)
+            {
+                manipulator->SetLocalPosition(action.LocalPosition());
+            });
+
+        actionDispatcher->EnableSnapToGrid()
+            ->GridSize(1.0f)
+            ->CameraState(cameraState)
+            ->MousePosition(initialPositionScreen)
+            ->MouseLButtonDown()
+            ->ExpectManipulatorBeingInteracted()
+            ->MousePosition(attemptPositionScreen)
+            ->MouseLButtonUp()
+            ->ExpectManipulatorNotBeingInteracted()
+            ->ExpectThat(manipulator->GetLocalPosition(), IsCloseTolerance(finalPositionWorld, 0.01f));
+    }
+
+    TEST_F(GridSnappingFixture, MouseDownAndMoveLinearManipulatorDoesNotSnapWithMovementSmallerThanHalfGridSize)
+    {
+        AZStd::shared_ptr<AzToolsFramework::LinearManipulator> linearManipulator(AzManipulatorTestFramework::CreateLinearManipulator(
+            m_viewportManipulatorInteraction->GetManipulatorManager().GetId(),
+            /*position=*/AZ::Vector3(0.0f, 10.0f, 0.0f),
+            /*radius=*/m_boundsRadius));
+
+        linearManipulator->SetAxis(AZ::Vector3::CreateAxisY());
+
+        ValidateManipulatorSnappingBehavior(linearManipulator, m_actionDispatcher.get(), m_cameraState);
+    }
+
+    TEST_F(GridSnappingFixture, MouseDownAndMovePlanarManipulatorDoesNotSnapWithMovementSmallerThanHalfGridSize)
+    {
+        AZStd::shared_ptr<AzToolsFramework::PlanarManipulator> planarManipulator(AzManipulatorTestFramework::CreatePlanarManipulator(
+            m_viewportManipulatorInteraction->GetManipulatorManager().GetId(),
+            /*position=*/AZ::Vector3(0.0f, 10.0f, 0.0f),
+            /*radius=*/m_boundsRadius));
+
+        planarManipulator->SetAxes(AZ::Vector3::CreateAxisY(), AZ::Vector3::CreateAxisZ());
+
+        ValidateManipulatorSnappingBehavior(planarManipulator, m_actionDispatcher.get(), m_cameraState);
     }
 } // namespace UnitTest

Code/Framework/AzNetworking/AzNetworking/UdpTransport/UdpFragmentQueue.cpp

@@ -139,7 +139,7 @@ namespace AzNetworking
 
         NetworkOutputSerializer networkSerializer(buffer.GetBuffer(), buffer.GetSize());
         {
-            ISerializer& serializer = networkSerializer; // To get the default typeinfo parameters in ISerializer
+            ISerializer& networkISerializer = networkSerializer; // To get the default typeinfo parameters in ISerializer
 
             // First, serialize out the header
             if (!header.SerializePacketFlags(networkSerializer))
@@ -148,7 +148,7 @@ namespace AzNetworking
                 return false;
             }
 
-            if (!serializer.Serialize(header, "Header"))
+            if (!networkISerializer.Serialize(header, "Header"))
             {
                 AZLOG(NET_FragmentQueue, "Reconstructed fragmented packet failed header serialization");
                 return false;

Code/Framework/AzNetworking/AzNetworking/Utilities/TimedThread.cpp

@@ -46,7 +46,7 @@ namespace AzNetworking
                 }
                 else if (m_updateRate < updateTimeMs)
                 {
-                    AZLOG_INFO("TimedThread bled %d ms", aznumeric_cast<int32_t>(updateTimeMs - m_updateRate));
+                    AZLOG(NET_TimedThread, "TimedThread bled %d ms", aznumeric_cast<int32_t>(updateTimeMs - m_updateRate));
                 }
             }
             OnStop();

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/BaseManipulator.cpp

@@ -433,6 +433,11 @@ namespace AzToolsFramework
         return m_manipulatorSpaceWithLocalTransform.GetSpace();
     }
 
+    const AZ::Vector3& Manipulators::GetNonUniformScale() const
+    {
+        return m_manipulatorSpaceWithLocalTransform.GetNonUniformScale();
+    }
+
     void Manipulators::SetSpace(const AZ::Transform& worldFromLocal)
     {
         m_manipulatorSpaceWithLocalTransform.SetSpace(worldFromLocal);

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/EditorVertexSelection.cpp

@@ -192,8 +192,7 @@ namespace AzToolsFramework
     /// for each vertex associated with the translation manipulator to use with offset calculations when updating.
     template<typename Vertex>
     void InitializeVertexLookup(
-        IndexedTranslationManipulator<Vertex>& translationManipulator,
-        const AZ::EntityId entityId, const AZ::Vector3& snapOffset)
+        IndexedTranslationManipulator<Vertex>& translationManipulator, const AZ::EntityId entityId)
     {
         AZ_PROFILE_FUNCTION(AZ::Debug::ProfileCategory::AzToolsFramework);
 
@@ -202,7 +201,7 @@ namespace AzToolsFramework
         AZ::FixedVerticesRequestBus<Vertex>::Bind(fixedVertices, entityId);
 
         translationManipulator.Process(
-            [snapOffset, fixedVertices]
+            [fixedVertices]
             (typename IndexedTranslationManipulator<Vertex>::VertexLookup& vertexLookup)
         {
             Vertex vertex;
@@ -213,7 +212,7 @@ namespace AzToolsFramework
 
             if (found)
             {
-                vertexLookup.m_start = vertex + AZ::AdaptVertexIn<Vertex>(snapOffset);
+                vertexLookup.m_start = vertex;
                 vertexLookup.m_offset = Vertex::CreateZero();
             }
         });
@@ -250,10 +249,10 @@ namespace AzToolsFramework
 
         // linear manipulator callbacks
         m_translationManipulator->m_manipulator.InstallLinearManipulatorMouseDownCallback(
-            [this](const LinearManipulator::Action& action)
+            [this]([[maybe_unused]] const LinearManipulator::Action& action)
         {
             BeginBatchMovement();
-            InitializeVertexLookup(*m_translationManipulator, GetEntityId(), action.m_start.m_positionSnapOffset);
+            InitializeVertexLookup(*m_translationManipulator, GetEntityId());
         });
 
         m_translationManipulator->m_manipulator.InstallLinearManipulatorMouseMoveCallback(
@@ -264,17 +263,17 @@ namespace AzToolsFramework
         });
 
         m_translationManipulator->m_manipulator.InstallLinearManipulatorMouseUpCallback(
-            [this](const LinearManipulator::Action& /*action*/)
+            [this]([[maybe_unused]] const LinearManipulator::Action& action)
         {
             EndBatchMovement();
         });
 
         // planar manipulator callbacks
         m_translationManipulator->m_manipulator.InstallPlanarManipulatorMouseDownCallback(
-            [this](const PlanarManipulator::Action& action)
+            [this]([[maybe_unused]] const PlanarManipulator::Action& action)
         {
             BeginBatchMovement();
-            InitializeVertexLookup(*m_translationManipulator, GetEntityId(), action.m_start.m_snapOffset);
+            InitializeVertexLookup(*m_translationManipulator, GetEntityId());
         });
 
         m_translationManipulator->m_manipulator.InstallPlanarManipulatorMouseMoveCallback(
@@ -285,17 +284,17 @@ namespace AzToolsFramework
         });
 
         m_translationManipulator->m_manipulator.InstallPlanarManipulatorMouseUpCallback(
-            [this](const PlanarManipulator::Action& /*action*/)
+            [this]([[maybe_unused]] const PlanarManipulator::Action& action)
         {
             EndBatchMovement();
         });
 
         // surface manipulator callbacks
         m_translationManipulator->m_manipulator.InstallSurfaceManipulatorMouseDownCallback(
-            [this](const SurfaceManipulator::Action& action)
+            [this]([[maybe_unused]] const SurfaceManipulator::Action& action)
         {
             BeginBatchMovement();
-            InitializeVertexLookup(*m_translationManipulator, GetEntityId(), action.m_start.m_snapOffset);
+            InitializeVertexLookup(*m_translationManipulator, GetEntityId());
         });
 
         m_translationManipulator->m_manipulator.InstallSurfaceManipulatorMouseMoveCallback(
@@ -306,7 +305,7 @@ namespace AzToolsFramework
         });
 
         m_translationManipulator->m_manipulator.InstallSurfaceManipulatorMouseUpCallback(
-            [this](const SurfaceManipulator::Action& /*action*/)
+            [this]([[maybe_unused]] const SurfaceManipulator::Action& action)
         {
             EndBatchMovement();
         });
@@ -893,7 +892,7 @@ namespace AzToolsFramework
         {
             BeginBatchMovement();
 
-            InitializeVertexLookup(*m_translationManipulator, GetEntityId(), AZ::Vector3::CreateZero());
+            InitializeVertexLookup(*m_translationManipulator, GetEntityId());
             // note: AdaptVertexIn/Out is to ensure we clamp the vertex local Z position to 0 if
             // dealing with Vector2s when setting the position of the manipulator.
             const AZ::Vector3 localOffset =

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/LinearManipulator.cpp

@@ -23,8 +23,8 @@ namespace AzToolsFramework
 {
     LinearManipulator::Starter CalculateLinearManipulationDataStart(
         const LinearManipulator::Fixed& fixed, const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale,
-        const AZ::Transform& localTransform, const GridSnapAction& gridSnapAction, const ViewportInteraction::MouseInteraction& interaction,
-        const float intersectionDistance, const AzFramework::CameraState& cameraState)
+        const AZ::Transform& localTransform, const ViewportInteraction::MouseInteraction& interaction, const float intersectionDistance,
+        const AzFramework::CameraState& cameraState)
     {
         const ManipulatorInteraction manipulatorInteraction =
             BuildManipulatorInteraction(
@@ -50,28 +50,9 @@ namespace AzToolsFramework
             manipulatorInteraction.m_localRayOrigin, manipulatorInteraction.m_localRayDirection,
             localIntersectionPoint, startTransition.m_localNormal, start.m_localHitPosition);
 
-        const float gridSize = gridSnapAction.m_gridSnapParams.m_gridSize;
-        const bool snapping = gridSnapAction.m_gridSnapParams.m_gridSnap;
-        const float scaleRecip = manipulatorInteraction.m_scaleReciprocal;
-
-        // calculate position amount to snap, to align with grid
-        const AZ::Vector3 positionSnapOffset = snapping && !gridSnapAction.m_localSnapping
-            ? CalculateSnappedOffset(localTransform.GetTranslation(), axis, gridSize * scaleRecip)
-            : AZ::Vector3::CreateZero();
-
-        const AZ::Vector3 localScale = AZ::Vector3(localTransform.GetUniformScale());
-        const AZ::Quaternion localRotation = QuaternionFromTransformNoScaling(localTransform);
-        // calculate scale amount to snap, to align to round scale value
-        const AZ::Vector3 scaleSnapOffset = snapping && !gridSnapAction.m_localSnapping
-            ? localRotation.GetInverseFull().TransformVector(CalculateSnappedOffset(
-                localRotation.TransformVector(localScale), axis, gridSize * scaleRecip))
-            : AZ::Vector3::CreateZero();
-
         start.m_screenPosition = interaction.m_mousePick.m_screenCoordinates;
-        start.m_positionSnapOffset = positionSnapOffset;
-        start.m_scaleSnapOffset = scaleSnapOffset;
-        start.m_localPosition = localTransform.GetTranslation() + positionSnapOffset;
-        start.m_localScale = localScale + scaleSnapOffset;
+        start.m_localPosition = localTransform.GetTranslation();
+        start.m_localScale = AZ::Vector3(localTransform.GetUniformScale());;
         start.m_localAxis = axis;
         // sign to determine which side of the linear axis we pressed
         // (useful to know when the visual axis flips to face the camera)
@@ -87,7 +68,7 @@ namespace AzToolsFramework
     LinearManipulator::Action CalculateLinearManipulationDataAction(
         const LinearManipulator::Fixed& fixed, const LinearManipulator::Starter& starter,
         const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale, const AZ::Transform& localTransform,
-        const GridSnapAction& gridSnapAction, const ViewportInteraction::MouseInteraction& interaction)
+        const GridSnapParameters& gridSnapParams, const ViewportInteraction::MouseInteraction& interaction)
     {
         const ManipulatorInteraction manipulatorInteraction =
             BuildManipulatorInteraction(
@@ -108,31 +89,34 @@ namespace AzToolsFramework
             GetCameraState(interaction.m_interactionId.m_viewportId));
 
         const AZ::Vector3 axis = TransformDirectionNoScaling(localTransform, fixed.m_axis);
-        // The local positions have been transformed to the reference frame of the object being manipulated. But they appear in the world
-        // with non-uniform scale applied, and the object being manipulated will want to work with unscaled deltas, so we need to divide by
-        // the non-uniform scale here.
+        // the local positions have been transformed to the reference frame of the object being manipulated, but they appear in the world
+        // with non-uniform scale applied, the object being manipulated will want to work with unscaled deltas, so we need to divide by
+        // the non-uniform scale here
         const AZ::Vector3 hitDelta = (localHitPosition - start.m_localHitPosition) / nonUniformScale;
         const AZ::Vector3 unsnappedOffset = axis * axis.Dot(hitDelta);
 
-        const float scaleRecip = manipulatorInteraction.m_scaleReciprocal * axis.Dot(manipulatorInteraction.m_nonUniformScaleReciprocal);
-        const float gridSize = gridSnapAction.m_gridSnapParams.m_gridSize;
-        const bool snapping = gridSnapAction.m_gridSnapParams.m_gridSnap;
+        const float scaleRecip =
+            manipulatorInteraction.m_scaleReciprocal * fixed.m_axis.Dot(manipulatorInteraction.m_nonUniformScaleReciprocal);
+        const float gridSize = gridSnapParams.m_gridSize;
+        const bool snapping = gridSnapParams.m_gridSnap;
 
         LinearManipulator::Action action;
         action.m_fixed = fixed;
         action.m_start = start;
         action.m_current.m_localPositionOffset = snapping
-            ? unsnappedOffset + CalculateSnappedOffset(unsnappedOffset, axis, gridSize * scaleRecip)
+            ? CalculateSnappedAmount(unsnappedOffset, axis, gridSize * scaleRecip)
             : unsnappedOffset;
         action.m_current.m_screenPosition = interaction.m_mousePick.m_screenCoordinates;
         action.m_viewportId = interaction.m_interactionId.m_viewportId;
 
         const AZ::Quaternion localRotation = QuaternionFromTransformNoScaling(localTransform);
-        const AZ::Vector3 scaledUnsnappedOffset = unsnappedOffset * startTransition.m_screenToWorldScale * NonUniformScaleReciprocal(nonUniformScale);
+        const AZ::Vector3 scaledUnsnappedOffset =
+            unsnappedOffset * startTransition.m_screenToWorldScale * NonUniformScaleReciprocal(nonUniformScale);
+
         // how much to adjust the scale based on movement
         const AZ::Quaternion invLocalRotation = localRotation.GetInverseFull();
         action.m_current.m_localScaleOffset = snapping
-            ? invLocalRotation.TransformVector((scaledUnsnappedOffset + CalculateSnappedOffset(scaledUnsnappedOffset, axis, gridSize * scaleRecip)))
+            ? invLocalRotation.TransformVector(CalculateSnappedAmount(scaledUnsnappedOffset, axis, gridSize * scaleRecip))
             : invLocalRotation.TransformVector(scaledUnsnappedOffset);
 
         // record what modifier keys are held during this action
@@ -171,19 +155,18 @@ namespace AzToolsFramework
         const ViewportInteraction::MouseInteraction& interaction, const float rayIntersectionDistance)
     {
         const AZ::Transform worldFromLocalUniformScale = TransformUniformScale(GetSpace());
-        const GridSnapParameters gridSnapParams = GridSnapSettings(interaction.m_interactionId.m_viewportId);
 
         // note: m_localTransform must not be made uniform as it may contain a local scale we want to snap
         m_starter = CalculateLinearManipulationDataStart(
-            m_fixed, worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(),
-            GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()), interaction, rayIntersectionDistance,
+            m_fixed, worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(), interaction, rayIntersectionDistance,
             GetCameraState(interaction.m_interactionId.m_viewportId));
 
         if (m_onLeftMouseDownCallback)
         {
+            const GridSnapParameters gridSnapParams = GridSnapSettings(interaction.m_interactionId.m_viewportId);
+
             m_onLeftMouseDownCallback(CalculateLinearManipulationDataAction(
-                m_fixed, m_starter, worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(),
-                GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()), interaction));
+                m_fixed, m_starter, worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(), gridSnapParams, interaction));
         }
     }
 
@@ -195,8 +178,8 @@ namespace AzToolsFramework
 
             // note: m_localTransform must not be made uniform as it may contain a local scale we want to snap
             m_onMouseMoveCallback(CalculateLinearManipulationDataAction(
-                m_fixed, m_starter, TransformUniformScale(GetSpace()), GetNonUniformScale(), GetLocalTransform(),
-                GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()), interaction));
+                m_fixed, m_starter, TransformUniformScale(GetSpace()), GetNonUniformScale(), GetLocalTransform(), gridSnapParams,
+                interaction));
         }
     }
 
@@ -208,8 +191,7 @@ namespace AzToolsFramework
 
             // note: m_localTransform must not be made uniform as it may contain a local scale we want to snap
             m_onLeftMouseUpCallback(CalculateLinearManipulationDataAction(
-                m_fixed, m_starter, TransformUniformScale(GetSpace()), GetNonUniformScale(), GetLocalTransform(),
-                GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()), interaction));
+                m_fixed, m_starter, TransformUniformScale(GetSpace()), GetNonUniformScale(), GetLocalTransform(), gridSnapParams, interaction));
         }
     }
 
@@ -232,8 +214,8 @@ namespace AzToolsFramework
                     GridSnapSettings(mouseInteraction.m_interactionId.m_viewportId);
 
                 const auto action = CalculateLinearManipulationDataAction(
-                    m_fixed, m_starter, TransformUniformScale(GetSpace()), GetNonUniformScale(), GetLocalTransform(),
-                    GridSnapAction(gridSnapParams, mouseInteraction.m_keyboardModifiers.Alt()), mouseInteraction);
+                    m_fixed, m_starter, TransformUniformScale(GetSpace()), GetNonUniformScale(), GetLocalTransform(), gridSnapParams,
+                    mouseInteraction);
 
                 // display the exact hit (ray intersection) of the mouse pick on the manipulator
                 DrawTransformAxes(

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/LinearManipulator.h

@@ -20,7 +20,7 @@
 
 namespace AzToolsFramework
 {
-    struct GridSnapAction;
+    struct GridSnapParameters;
 
     /// LinearManipulator serves as a visual tool for users to modify values
     /// in one dimension on an axis defined in 3D space.
@@ -68,8 +68,6 @@ namespace AzToolsFramework
             AZ::Vector3 m_localScale; ///< The current scale of the manipulator in local space.
             AZ::Vector3 m_localHitPosition; ///< The intersection point in local space between the ray and the manipulator when the mouse down event happens.
             AZ::Vector3 m_localAxis; ///< The axis in the local space of the manipulator itself.
-            AZ::Vector3 m_positionSnapOffset; ///< The snap offset amount to ensure manipulator is aligned to the grid.
-            AZ::Vector3 m_scaleSnapOffset; ///< The snap offset amount to ensure manipulator is aligned to round scale increments.
             float m_sign; ///< Used to determine which side of the axis we clicked on in case it's flipped to face the camera.
             AzFramework::ScreenPoint m_screenPosition; ///< The initial position in screen space of the manipulator.
         };
@@ -91,7 +89,7 @@ namespace AzToolsFramework
             ViewportInteraction::KeyboardModifiers m_modifiers;
             int m_viewportId; ///< The id of the viewport this manipulator is being used in.
             AZ::Vector3 LocalScale() const { return m_start.m_localScale + m_current.m_localScaleOffset; }
-            AZ::Vector3 LocalScaleOffset() const { return m_start.m_scaleSnapOffset + m_current.m_localScaleOffset; }
+            AZ::Vector3 LocalScaleOffset() const { return m_current.m_localScaleOffset; }
             AZ::Vector3 LocalPosition() const { return m_start.m_localPosition + m_current.m_localPositionOffset; }
             AZ::Vector3 LocalPositionOffset() const { return m_current.m_localPositionOffset; }
             AZ::Vector2 ScreenOffset() const
@@ -162,11 +160,11 @@ namespace AzToolsFramework
 
     LinearManipulator::Starter CalculateLinearManipulationDataStart(
         const LinearManipulator::Fixed& fixed, const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale,
-        const AZ::Transform& localTransform, const GridSnapAction& gridSnapAction, const ViewportInteraction::MouseInteraction& interaction,
-        float intersectionDistance, const AzFramework::CameraState& cameraState);
+        const AZ::Transform& localTransform, const ViewportInteraction::MouseInteraction& interaction, float intersectionDistance,
+        const AzFramework::CameraState& cameraState);
 
     LinearManipulator::Action CalculateLinearManipulationDataAction(
         const LinearManipulator::Fixed& fixed, const LinearManipulator::Starter& starter,
         const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale, const AZ::Transform& localTransform,
-        const GridSnapAction& gridSnapAction, const ViewportInteraction::MouseInteraction& interaction);
+        const GridSnapParameters& gridSnapParams, const ViewportInteraction::MouseInteraction& interaction);
 } // namespace AzToolsFramework

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/ManipulatorSnapping.cpp

@@ -42,12 +42,6 @@ namespace AzToolsFramework
     {
     }
 
-    GridSnapAction::GridSnapAction(const GridSnapParameters& gridSnapParameters, const bool localSnapping)
-        : m_gridSnapParams(gridSnapParameters)
-        , m_localSnapping(localSnapping)
-    {
-    }
-
     ManipulatorInteraction BuildManipulatorInteraction(
         const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale,
         const AZ::Vector3& worldRayOrigin, const AZ::Vector3& worldRayDirection)
@@ -57,19 +51,39 @@ namespace AzToolsFramework
 
         return {localFromWorldUniform.TransformPoint(worldRayOrigin),
                 TransformDirectionNoScaling(localFromWorldUniform, worldRayDirection),
-                ScaleReciprocal(worldFromLocalUniform),
-                NonUniformScaleReciprocal(nonUniformScale)};
+                NonUniformScaleReciprocal(nonUniformScale),
+                ScaleReciprocal(worldFromLocalUniform)};
     }
 
-    AZ::Vector3 CalculateSnappedOffset(
-        const AZ::Vector3& unsnappedPosition, const AZ::Vector3& axis, const float size)
+    struct SnapAdjustment
+    {
+        float m_existingSnapDistance; //!< How far to snap up or down to align to the grid.
+        float m_nextSnapDistance; //!< The snap increment (will return full signed value (grid size) when distance
+                                  //!< moved is greater than half of the grid size in either direction).
+    };
+
+    static SnapAdjustment CalculateSnapDistance(const AZ::Vector3& unsnappedPosition, const AZ::Vector3& axis, const float size)
     {
         // calculate total distance along axis
         const float axisDistance = axis.Dot(unsnappedPosition);
         // round to nearest step size
         const float snappedAxisDistance = floorf((axisDistance / size) + 0.5f) * size;
+
+        return { axisDistance, snappedAxisDistance };
+    }
+
+    AZ::Vector3 CalculateSnappedOffset(const AZ::Vector3& unsnappedPosition, const AZ::Vector3& axis, const float size)
+    {
+        const auto snapAdjustment = CalculateSnapDistance(unsnappedPosition, axis, size);
         // return offset along axis to snap to step size
-        return axis * (snappedAxisDistance - axisDistance);
+        return axis * (snapAdjustment.m_nextSnapDistance - snapAdjustment.m_existingSnapDistance);
+    }
+
+    AZ::Vector3 CalculateSnappedAmount(const AZ::Vector3& unsnappedPosition, const AZ::Vector3& axis, const float size)
+    {
+        const auto snapAdjustment = CalculateSnapDistance(unsnappedPosition, axis, size);
+        // return offset along axis to snap to step size
+        return axis * snapAdjustment.m_nextSnapDistance;
     }
 
     AZ::Vector3 CalculateSnappedTerrainPosition(

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/ManipulatorSnapping.h

@@ -31,24 +31,15 @@ namespace AzToolsFramework
         float m_gridSize;
     };
 
-    /// Structure to encapsulate the current grid snapping state.
-    struct GridSnapAction
-    {
-        GridSnapAction(const GridSnapParameters& gridSnapParameters, bool localSnapping);
-
-        GridSnapParameters m_gridSnapParams;
-        bool m_localSnapping;
-    };
-
     /// Structure to hold transformed incoming viewport interaction from world space to manipulator space.
     struct ManipulatorInteraction
     {
         AZ::Vector3 m_localRayOrigin; ///< The ray origin (start) in the reference from of the manipulator.
         AZ::Vector3 m_localRayDirection; ///< The ray direction in the reference from of the manipulator.
-        float m_scaleReciprocal; ///< The scale reciprocal (1.0 / scale) of the transform used to move the
-                                 ///< ray from world space to local space.
         AZ::Vector3 m_nonUniformScaleReciprocal; ///< Handles inverting any non-uniform scale which was applied
                                                  ///< separately from the transform.
+        float m_scaleReciprocal; ///< The scale reciprocal (1.0 / scale) of the transform used to move the
+                                 ///< ray from world space to local space.
     };
 
     /// Build a ManipulatorInteraction structure from the incoming viewport interaction.
@@ -56,11 +47,16 @@ namespace AzToolsFramework
         const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale,
         const AZ::Vector3& worldRayOrigin, const AZ::Vector3& worldRayDirection);
 
-    /// Calculate the offset along an axis to adjust a position
-    /// to stay snapped to a given grid size.
+    /// Calculate the offset along an axis to adjust a position to stay snapped to a given grid size.
+    /// @note This is snap up or down to the nearest grid segment (e.g. 0.2 snaps to 0.0 -> delta 0.2,
+    /// 0.7 snaps to 1.0 -> delta 0.3).
     AZ::Vector3 CalculateSnappedOffset(
         const AZ::Vector3& unsnappedPosition, const AZ::Vector3& axis, float size);
 
+    /// Return the amount to snap from the starting position given the current grid size.
+    /// @note A movement of more than half size (in either direction) will cause a snap by size.
+    AZ::Vector3 CalculateSnappedAmount(const AZ::Vector3& unsnappedPosition, const AZ::Vector3& axis, float size);
+
     /// For a given point on the terrain, calculate the closest xy position snapped to the grid
     /// (z position is aligned to terrain height, not snapped to z grid)
     AZ::Vector3 CalculateSnappedTerrainPosition(

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/MultiLinearManipulator.cpp

@@ -59,17 +59,16 @@ namespace AzToolsFramework
         const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale, const AZ::Transform& localTransform,
         const ViewportInteraction::MouseInteraction& interaction,
         const AZStd::vector<LinearManipulator::Fixed>& fixedAxes,
-        const AZStd::vector<LinearManipulator::Starter>& starterStates, const GridSnapAction& gridSnapAction)
+        const AZStd::vector<LinearManipulator::Starter>& starterStates, const GridSnapParameters& gridSnapParams)
     {
         MultiLinearManipulator::Action action;
         action.m_viewportId = interaction.m_interactionId.m_viewportId;
         // build up action state for each axis
         for (size_t fixedIndex = 0; fixedIndex < fixedAxes.size(); ++fixedIndex)
         {
-            action.m_actions.push_back(
-                CalculateLinearManipulationDataAction(
-                    fixedAxes[fixedIndex], starterStates[fixedIndex], worldFromLocal, nonUniformScale, localTransform,
-                    gridSnapAction, interaction));
+            action.m_actions.push_back(CalculateLinearManipulationDataAction(
+                fixedAxes[fixedIndex], starterStates[fixedIndex], worldFromLocal, nonUniformScale, localTransform, gridSnapParams,
+                interaction));
         }
 
         return action;
@@ -79,8 +78,6 @@ namespace AzToolsFramework
         const ViewportInteraction::MouseInteraction& interaction, const float rayIntersectionDistance)
     {
         const AZ::Transform worldFromLocalUniformScale = TransformUniformScale(GetSpace());
-
-        const GridSnapParameters gridSnapParams = GridSnapSettings(interaction.m_interactionId.m_viewportId);
         const AzFramework::CameraState cameraState = GetCameraState(interaction.m_interactionId.m_viewportId);
 
         // build up initial start state for each axis
@@ -88,20 +85,19 @@ namespace AzToolsFramework
         {
             // note: m_localTransform must not be made uniform as it may contain a local scale we want to snap
             const auto linearStart = CalculateLinearManipulationDataStart(
-                fixed, worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(),
-                GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()), interaction,
-                rayIntersectionDistance, cameraState);
+                fixed, worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(), interaction, rayIntersectionDistance,
+                cameraState);
 
             m_starters.push_back(linearStart);
         }
 
         if (m_onLeftMouseDownCallback)
         {
-            const GridSnapAction gridSnapAction = GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt());
+            const GridSnapParameters gridSnapParams = GridSnapSettings(interaction.m_interactionId.m_viewportId);
             // pass action containing all linear actions for each axis to handler
             m_onLeftMouseDownCallback(BuildMultiLinearManipulatorAction(
                 worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(),
-                interaction, m_fixedAxes, m_starters, gridSnapAction));
+                interaction, m_fixedAxes, m_starters, gridSnapParams));
         }
     }
 
@@ -111,11 +107,9 @@ namespace AzToolsFramework
         {
             const AZ::Transform worldFromLocalUniformScale = TransformUniformScale(GetSpace());
             const GridSnapParameters gridSnapParams = GridSnapSettings(interaction.m_interactionId.m_viewportId);
-            const GridSnapAction gridSnapAction = GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt());
-
             m_onMouseMoveCallback(BuildMultiLinearManipulatorAction(
                 worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(),
-                interaction, m_fixedAxes, m_starters, gridSnapAction));
+                interaction, m_fixedAxes, m_starters, gridSnapParams));
         }
     }
 
@@ -125,11 +119,9 @@ namespace AzToolsFramework
         {
             const AZ::Transform worldFromLocalUniformScale = TransformUniformScale(GetSpace());
             const GridSnapParameters gridSnapParams = GridSnapSettings(interaction.m_interactionId.m_viewportId);
-            const GridSnapAction gridSnapAction = GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt());
-
             m_onLeftMouseUpCallback(BuildMultiLinearManipulatorAction(
                 worldFromLocalUniformScale, GetNonUniformScale(), GetLocalTransform(),
-                interaction, m_fixedAxes, m_starters, gridSnapAction));
+                interaction, m_fixedAxes, m_starters, gridSnapParams));
 
             m_starters.clear();
         }

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/MultiLinearManipulator.h

@@ -20,8 +20,6 @@
 
 namespace AzToolsFramework
 {
-    struct GridSnapAction;
-
     //! MultiLinearManipulator serves as a visual tool for users to modify values
     //! in one or more dimensions on axes defined in 3D space.
     class MultiLinearManipulator

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/PlanarManipulator.cpp

@@ -22,8 +22,7 @@
 namespace AzToolsFramework
 {
     PlanarManipulator::StartInternal PlanarManipulator::CalculateManipulationDataStart(
-        const Fixed& fixed, const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale,
-        const AZ::Transform& localTransform, const GridSnapAction& gridSnapAction,
+        const Fixed& fixed, const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale, const AZ::Transform& localTransform,
         const ViewportInteraction::MouseInteraction& interaction, const float intersectionDistance)
     {
         const ManipulatorInteraction manipulatorInteraction =
@@ -31,8 +30,6 @@ namespace AzToolsFramework
                 worldFromLocal, nonUniformScale, interaction.m_mousePick.m_rayOrigin, interaction.m_mousePick.m_rayDirection);
 
         const AZ::Vector3 normal = TransformDirectionNoScaling(localTransform, fixed.m_normal);
-        const AZ::Vector3 axis1 = TransformDirectionNoScaling(localTransform, fixed.m_axis1);
-        const AZ::Vector3 axis2 = TransformDirectionNoScaling(localTransform, fixed.m_axis2);
 
         // initial intersect point
         const AZ::Vector3 localIntersectionPoint =
@@ -43,25 +40,14 @@ namespace AzToolsFramework
             manipulatorInteraction.m_localRayOrigin, manipulatorInteraction.m_localRayDirection,
             localIntersectionPoint, normal, startInternal.m_localHitPosition);
 
-        const float scaleRecip = manipulatorInteraction.m_scaleReciprocal;
-        const float gridSize = gridSnapAction.m_gridSnapParams.m_gridSize;
-        const bool snapping = gridSnapAction.m_gridSnapParams.m_gridSnap;
-
-        // calculate amount to snap to align with grid
-        const AZ::Vector3 snapOffset = snapping && !gridSnapAction.m_localSnapping
-            ? CalculateSnappedOffset(localTransform.GetTranslation(), axis1, gridSize * scaleRecip) +
-              CalculateSnappedOffset(localTransform.GetTranslation(), axis2, gridSize * scaleRecip)
-            : AZ::Vector3::CreateZero();
-
-        startInternal.m_snapOffset = snapOffset;
-        startInternal.m_localPosition = localTransform.GetTranslation() + snapOffset;
+        startInternal.m_localPosition = localTransform.GetTranslation();
 
         return startInternal;
     }
 
     PlanarManipulator::Action PlanarManipulator::CalculateManipulationDataAction(
-        const Fixed& fixed, const StartInternal& startInternal, const AZ::Transform& worldFromLocal,
-        const AZ::Vector3& nonUniformScale, const AZ::Transform& localTransform, const GridSnapAction& gridSnapAction,
+        const Fixed& fixed, const StartInternal& startInternal, const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale,
+        const AZ::Transform& localTransform, const GridSnapParameters& gridSnapParams,
         const ViewportInteraction::MouseInteraction& interaction)
     {
         const ManipulatorInteraction manipulatorInteraction =
@@ -88,20 +74,18 @@ namespace AzToolsFramework
         const AZ::Vector3 hitDelta = (localHitPosition - startInternal.m_localHitPosition) / nonUniformScale;
         const AZ::Vector3 unsnappedOffset = axis1.Dot(hitDelta) * axis1 + axis2.Dot(hitDelta) * axis2;
 
-        const float scaleRecip = manipulatorInteraction.m_scaleReciprocal;
         const AZ::Vector3 nonUniformScaleRecip = manipulatorInteraction.m_nonUniformScaleReciprocal;
-        const float gridSize = gridSnapAction.m_gridSnapParams.m_gridSize;
-        const bool snapping = gridSnapAction.m_gridSnapParams.m_gridSnap;
+        const float scaleRecip = manipulatorInteraction.m_scaleReciprocal;
+        const float gridSize = gridSnapParams.m_gridSize;
+        const bool snapping = gridSnapParams.m_gridSnap;
 
         Action action;
         action.m_fixed = fixed;
         action.m_start.m_localPosition = startInternal.m_localPosition;
-        action.m_start.m_snapOffset = startInternal.m_snapOffset;
         action.m_start.m_localHitPosition = startInternal.m_localHitPosition;
         action.m_current.m_localOffset = snapping
-            ? unsnappedOffset +
-                CalculateSnappedOffset(unsnappedOffset, axis1, gridSize * scaleRecip * nonUniformScaleRecip.Dot(axis1)) +
-                CalculateSnappedOffset(unsnappedOffset, axis2, gridSize * scaleRecip * nonUniformScaleRecip.Dot(axis2))
+            ? CalculateSnappedAmount(unsnappedOffset, axis1, gridSize * scaleRecip * nonUniformScaleRecip.Dot(fixed.m_axis1)) +
+                CalculateSnappedAmount(unsnappedOffset, axis2, gridSize * scaleRecip * nonUniformScaleRecip.Dot(fixed.m_axis2))
             : unsnappedOffset;
 
         // record what modifier keys are held during this action
@@ -141,18 +125,17 @@ namespace AzToolsFramework
     {
         const AZ::Transform worldFromLocalUniformScale = TransformUniformScale(GetSpace());
 
-        const GridSnapParameters gridSnapParams = GridSnapSettings(interaction.m_interactionId.m_viewportId);
-
         m_startInternal = CalculateManipulationDataStart(
             m_fixed, worldFromLocalUniformScale, GetNonUniformScale(), TransformNormalizedScale(GetLocalTransform()),
-            GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()),
             interaction, rayIntersectionDistance);
 
         if (m_onLeftMouseDownCallback)
         {
+            const GridSnapParameters gridSnapParams = GridSnapSettings(interaction.m_interactionId.m_viewportId);
+
             m_onLeftMouseDownCallback(CalculateManipulationDataAction(
                 m_fixed, m_startInternal, worldFromLocalUniformScale, GetNonUniformScale(), TransformNormalizedScale(GetLocalTransform()),
-                GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()), interaction));
+                gridSnapParams, interaction));
         }
     }
 
@@ -164,8 +147,7 @@ namespace AzToolsFramework
 
             m_onMouseMoveCallback(CalculateManipulationDataAction(
                 m_fixed, m_startInternal, TransformUniformScale(GetSpace()), GetNonUniformScale(),
-                TransformNormalizedScale(GetLocalTransform()),
-                GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()), interaction));
+                TransformNormalizedScale(GetLocalTransform()), gridSnapParams, interaction));
         }
     }
 
@@ -177,8 +159,7 @@ namespace AzToolsFramework
 
             m_onLeftMouseUpCallback(CalculateManipulationDataAction(
                 m_fixed, m_startInternal, TransformUniformScale(GetSpace()), GetNonUniformScale(),
-                TransformNormalizedScale(GetLocalTransform()),
-                GridSnapAction(gridSnapParams, interaction.m_keyboardModifiers.Alt()), interaction));
+                TransformNormalizedScale(GetLocalTransform()), gridSnapParams, interaction));
         }
     }
 
@@ -195,8 +176,7 @@ namespace AzToolsFramework
                 const GridSnapParameters gridSnapParams = GridSnapSettings(mouseInteraction.m_interactionId.m_viewportId);
                 const auto action = CalculateManipulationDataAction(
                     m_fixed, m_startInternal, TransformUniformScale(GetSpace()), GetNonUniformScale(),
-                    TransformNormalizedScale(GetLocalTransform()),
-                    GridSnapAction(gridSnapParams, mouseInteraction.m_keyboardModifiers.Alt()), mouseInteraction);
+                    TransformNormalizedScale(GetLocalTransform()), gridSnapParams, mouseInteraction);
 
                 // display the exact hit (ray intersection) of the mouse pick on the manipulator
                 DrawTransformAxes(

Code/Framework/AzToolsFramework/AzToolsFramework/Manipulators/PlanarManipulator.h

@@ -21,7 +21,7 @@
 namespace AzToolsFramework
 {
     class ManipulatorView;
-    struct GridSnapAction;
+    struct GridSnapParameters;
 
     /// PlanarManipulator serves as a visual tool for users to modify values
     /// in two dimension in a plane defined two non-collinear axes in 3D space.
@@ -58,7 +58,6 @@ namespace AzToolsFramework
         {
             AZ::Vector3 m_localPosition; ///< The current position of the manipulator in local space.
             AZ::Vector3 m_localHitPosition; ///< The intersection point in local space between the ray and the manipulator when the mouse down event happens.
-            AZ::Vector3 m_snapOffset; ///< The snap offset amount to ensure manipulator is aligned to the grid.
         };
 
         /// The state of the manipulator during an interaction.
@@ -120,7 +119,6 @@ namespace AzToolsFramework
         {
             AZ::Vector3 m_localPosition; ///< The starting position of the manipulator in local space.
             AZ::Vector3 m_localHitPosition; ///< The intersection point in world space between the ray and the manipulator when the mouse down event happens.
-            AZ::Vector3 m_snapOffset; ///< The snap offset amount to ensure manipulator is aligned to the grid.
         };
 
         Fixed m_fixed;
@@ -134,12 +132,11 @@ namespace AzToolsFramework
 
         static StartInternal CalculateManipulationDataStart(
             const Fixed& fixed, const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale,
-            const AZ::Transform& localTransform, const GridSnapAction& gridSnapAction,
-            const ViewportInteraction::MouseInteraction& interaction, float intersectionDistance);
+            const AZ::Transform& localTransform, const ViewportInteraction::MouseInteraction& interaction, float intersectionDistance);
 
         static Action CalculateManipulationDataAction(
-            const Fixed& fixed, const StartInternal& startInternal, const AZ::Transform& worldFromLocal,
-            const AZ::Vector3& nonUniformScale, const AZ::Transform& localTransform,
-            const GridSnapAction& gridSnapAction, const ViewportInteraction::MouseInteraction& interaction);
+            const Fixed& fixed, const StartInternal& startInternal, const AZ::Transform& worldFromLocal, const AZ::Vector3& nonUniformScale,
+            const AZ::Transform& localTransform, const GridSnapParameters& gridSnapParams,
+            const ViewportInteraction::MouseInteraction& interaction);
     };
 } // namespace AzToolsFramework

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.cpp

@@ -18,6 +18,7 @@
 #include <AzToolsFramework/Entity/EditorEntityContextBus.h>
 #include <AzToolsFramework/Entity/EditorEntityHelpers.h>
 #include <AzToolsFramework/Prefab/Instance/Instance.h>
+#include <AzToolsFramework/Prefab/PrefabDomUtils.h>
 #include <AzToolsFramework/Prefab/Instance/InstanceEntityMapperInterface.h>
 #include <AzToolsFramework/Prefab/Instance/TemplateInstanceMapperInterface.h>
 
@@ -49,8 +50,7 @@ namespace AzToolsFramework
             m_alias = GenerateInstanceAlias();
             m_containerEntity = containerEntity ? AZStd::move(containerEntity)
                                                 : AZStd::make_unique<AZ::Entity>();
-            EntityAlias containerEntityAlias = GenerateEntityAlias();
-            RegisterEntity(m_containerEntity->GetId(), containerEntityAlias);
+            RegisterEntity(m_containerEntity->GetId(), PrefabDomUtils::ContainerEntityName);
         }
 
         Instance::~Instance()
@@ -311,8 +311,15 @@ namespace AzToolsFramework
         Instance& Instance::AddInstance(AZStd::unique_ptr<Instance> instance)
         {
             InstanceAlias newInstanceAlias = GenerateInstanceAlias();
+            return AddInstance(AZStd::move(instance), newInstanceAlias);
+        }
+
+        Instance& Instance::AddInstance(AZStd::unique_ptr<Instance> instance, InstanceAlias newInstanceAlias)
+        {
             AZ_Assert(instance.get(), "instance argument is nullptr");
-            AZ_Assert(m_nestedInstances.find(newInstanceAlias) == m_nestedInstances.end(), "InstanceAlias' unique id collision, this should never happen.");
+            AZ_Assert(
+                m_nestedInstances.find(newInstanceAlias) == m_nestedInstances.end(),
+                "InstanceAlias' unique id collision, this should never happen.");
             instance->m_parent = this;
             instance->m_alias = newInstanceAlias;
             return *(m_nestedInstances[newInstanceAlias] = std::move(instance));
@@ -613,6 +620,7 @@ namespace AzToolsFramework
 
         AZStd::unique_ptr<AZ::Entity> Instance::DetachContainerEntity()
         {
+            m_instanceEntityMapper->UnregisterEntity(m_containerEntity->GetId());
             return AZStd::move(m_containerEntity);
         }
     }

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.h

@@ -48,6 +48,7 @@ namespace AzToolsFramework
         using EntityAliasOptionalReference = AZStd::optional<AZStd::reference_wrapper<EntityAlias>>;
         using InstanceOptionalReference = AZStd::optional<AZStd::reference_wrapper<Instance>>;
         using InstanceOptionalConstReference = AZStd::optional<AZStd::reference_wrapper<const Instance>>;
+
         using InstanceSet = AZStd::unordered_set<Instance*>;
         using InstanceSetConstReference = AZStd::optional<AZStd::reference_wrapper<const InstanceSet>>;
         using EntityOptionalReference = AZStd::optional<AZStd::reference_wrapper<AZ::Entity>>;
@@ -85,12 +86,14 @@ namespace AzToolsFramework
             bool AddEntity(AZ::Entity& entity);
             bool AddEntity(AZ::Entity& entity, EntityAlias entityAlias);
             AZStd::unique_ptr<AZ::Entity> DetachEntity(const AZ::EntityId& entityId);
+            void DetachEntities(const AZStd::function<void(AZStd::unique_ptr<AZ::Entity>)>& callback);
             void DetachNestedEntities(const AZStd::function<void(AZStd::unique_ptr<AZ::Entity>)>& callback);
             void RemoveNestedEntities(const AZStd::function<bool(const AZStd::unique_ptr<AZ::Entity>&)>& filter);
 
             void Reset();
 
             Instance& AddInstance(AZStd::unique_ptr<Instance> instance);
+            Instance& AddInstance(AZStd::unique_ptr<Instance> instance, InstanceAlias instanceAlias);
             AZStd::unique_ptr<Instance> DetachNestedInstance(const InstanceAlias& instanceAlias);
 
             /**
@@ -171,6 +174,8 @@ namespace AzToolsFramework
             static EntityAlias GenerateEntityAlias();
             AliasPath GetAbsoluteInstanceAliasPath() const;
 
+            static InstanceAlias GenerateInstanceAlias();
+
         protected:
             /**
             * Gets the entities owned by this instance
@@ -182,14 +187,11 @@ namespace AzToolsFramework
 
             void ClearEntities();
 
-            void DetachEntities(const AZStd::function<void(AZStd::unique_ptr<AZ::Entity>)>& callback);
             void RemoveEntities(const AZStd::function<bool(const AZStd::unique_ptr<AZ::Entity>&)>& filter);
 
             bool RegisterEntity(const AZ::EntityId& entityId, const EntityAlias& entityAlias);
             AZStd::unique_ptr<AZ::Entity> DetachEntity(const EntityAlias& entityAlias);
 
-            static InstanceAlias GenerateInstanceAlias();
-
             // Provide access to private data members in the serializer
             friend class JsonInstanceSerializer;
             friend class InstanceEntityIdMapper;

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/InstanceUpdateExecutor.cpp

@@ -152,6 +152,30 @@ namespace AzToolsFramework
                         Instance::EntityList newEntities;
                         if (PrefabDomUtils::LoadInstanceFromPrefabDom(*instanceToUpdate, newEntities, currentTemplate.GetPrefabDom()))
                         {
+                            // If a link was created for a nested instance before the changes were propagated,
+                            // then we associate it correctly here
+                            instanceToUpdate->GetNestedInstances([&](AZStd::unique_ptr<Instance>& nestedInstance) {
+                                if (nestedInstance->GetLinkId() != InvalidLinkId)
+                                {
+                                    return;
+                                }
+
+                                for (auto linkId : currentTemplate.GetLinks())
+                                {
+                                    LinkReference nestedLink = m_prefabSystemComponentInterface->FindLink(linkId);
+                                    if (!nestedLink.has_value())
+                                    {
+                                        continue;
+                                    }
+
+                                    if (nestedLink->get().GetInstanceName() == nestedInstance->GetInstanceAlias())
+                                    {
+                                        nestedInstance->SetLinkId(linkId);
+                                        break;
+                                    }
+                                }
+                            });
+
                             AzToolsFramework::EditorEntityContextRequestBus::Broadcast(
                                 &AzToolsFramework::EditorEntityContextRequests::HandleEntitiesAdded, newEntities);
                         }

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabPublicHandler.cpp

@@ -19,6 +19,7 @@
 #include <AzToolsFramework/Entity/EditorEntityContextBus.h>
 #include <AzToolsFramework/Entity/EditorEntityHelpers.h>
 #include <AzToolsFramework/Entity/EditorEntityInfoBus.h>
+#include <AzToolsFramework/Prefab/EditorPrefabComponent.h>
 #include <AzToolsFramework/Entity/PrefabEditorEntityOwnershipInterface.h>
 #include <AzToolsFramework/Prefab/Instance/Instance.h>
 #include <AzToolsFramework/Prefab/Instance/InstanceEntityIdMapper.h>
@@ -191,24 +192,7 @@ namespace AzToolsFramework
                     if (nestedInstanceLinkPatchesMap.contains(nestedInstance.get()))
                     {
                         previousPatch = AZStd::move(nestedInstanceLinkPatchesMap[nestedInstance.get()]);
-                        rapidjson::StringBuffer buffer;
-                        rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
-                        previousPatch.Accept(writer);
-                        QString previousPatchString(buffer.GetString());
-
-                        for (AZ::Entity* entity : entities)
-                        {
-                            AZ::EntityId entityId = entity->GetId();
-                            AZStd::string oldEntityAlias = oldEntityAliases[entityId];
-                            EntityAliasOptionalReference newEntityAlias = instanceToCreate->get().GetEntityAlias(entityId);
-                            AZ_Assert(
-                                newEntityAlias.has_value(),
-                                "Could not fetch entity alias for entity with id '%llu' during prefab creation.",
-                                static_cast<AZ::u64>(entityId));
-                            ReplaceOldAliases(previousPatchString, oldEntityAlias, newEntityAlias->get());
-                        }
-
-                        previousPatch.Parse(previousPatchString.toUtf8().constData());
+                        UpdateLinkPatchesWithNewEntityAliases(previousPatch, oldEntityAliases, instanceToCreate->get());
                     }
 
                     // These link creations shouldn't be undone because that would put the template in a non-usable state if a user
@@ -243,11 +227,33 @@ namespace AzToolsFramework
                     instanceToCreate->get(), commonRootEntityOwningInstance->get().GetTemplateId(), undoBatch.GetUndoBatch(),
                     AZStd::move(patch));
 
+                // Reset the transform of the container entity so that the new values aren't saved in the new prefab's dom.
+                // The new values were saved in the link, so propagation will apply them correctly.
+                {
+                    AZ::Entity* containerEntity = GetEntityById(containerEntityId);
+
+                    PrefabDom containerBeforeReset;
+                    m_instanceToTemplateInterface->GenerateDomForEntity(containerBeforeReset, *containerEntity);
+
+                    AZ::TransformBus::Event(containerEntityId, &AZ::TransformBus::Events::SetParent, AZ::EntityId());
+                    AZ::TransformBus::Event(containerEntityId, &AZ::TransformBus::Events::SetLocalTM, AZ::Transform::CreateIdentity());
+
+                    PrefabDom containerAfterReset;
+                    m_instanceToTemplateInterface->GenerateDomForEntity(containerAfterReset, *containerEntity);
+
+                    // Update the state of the entity
+                    PrefabUndoEntityUpdate* state = aznew PrefabUndoEntityUpdate(AZStd::to_string(static_cast<AZ::u64>(containerEntityId)));
+                    state->SetParent(undoBatch.GetUndoBatch());
+                    state->Capture(containerBeforeReset, containerAfterReset, containerEntityId);
+
+                    state->Redo();
+                }
+
                 // This clears any entities marked as dirty due to reparenting of entities during the process of creating a prefab.
-                // We are doing this so that the changes in those enities are not queued up twice for propagation.
+                // We are doing this so that the changes in those entities are not queued up twice for propagation.
                 AzToolsFramework::ToolsApplicationRequestBus::Broadcast(
                     &AzToolsFramework::ToolsApplicationRequestBus::Events::ClearDirtyEntities);
-                
+
                 // Select Container Entity
                 {
                     auto selectionUndo = aznew SelectionCommand({containerEntityId}, "Select Prefab Container Entity");
@@ -291,7 +297,7 @@ namespace AzToolsFramework
             m_instanceToTemplateInterface->AppendEntityAliasToPatchPaths(patch, containerEntityId);
 
             // Update the cache - this prevents these changes from being stored in the regular undo/redo nodes
-            m_prefabUndoCache.Store(containerEntityId, AZStd::move(containerEntityDomAfter));
+            m_prefabUndoCache.Store(containerEntityId, AZStd::move(containerEntityDomAfter), parentEntityId);
 
             return AZStd::move(patch);
         }
@@ -385,8 +391,8 @@ namespace AzToolsFramework
 
                 CreateLink(instanceToCreate->get(), instanceToParentUnder->get().GetTemplateId(), undoBatch.GetUndoBatch(), AZStd::move(patch));
 
-                // Update the cache - this prevents these changes from being stored in the regular undo/redo nodes
-                m_prefabUndoCache.Store(containerEntityId, AZStd::move(containerEntityDomAfter));
+                AzToolsFramework::ToolsApplicationRequestBus::Broadcast(
+                    &AzToolsFramework::ToolsApplicationRequestBus::Events::ClearDirtyEntities);
             }
 
             return AZ::Success();
@@ -589,54 +595,199 @@ namespace AzToolsFramework
         {
             // Create Undo node on entities if they belong to an instance
             InstanceOptionalReference owningInstance = m_instanceEntityMapperInterface->FindOwningInstance(entityId);
-
-            if (owningInstance.has_value())
+            if (!owningInstance.has_value())
             {
-                PrefabDom afterState;
-                AZ::Entity* entity = GetEntityById(entityId);
-                if (entity)
+                return;
+            }
+
+            AZ::Entity* entity = GetEntityById(entityId);
+            if (!entity)
+            {
+                m_prefabUndoCache.PurgeCache(entityId);
+                return;
+            }
+
+            PrefabDom beforeState;
+            AZ::EntityId beforeParentId;
+            m_prefabUndoCache.Retrieve(entityId, beforeState, beforeParentId);
+
+            PrefabDom afterState;
+            AZ::EntityId afterParentId;
+            AZ::TransformBus::EventResult(afterParentId, entityId, &AZ::TransformBus::Events::GetParentId);
+
+            m_instanceToTemplateInterface->GenerateDomForEntity(afterState, *entity);
+
+            PrefabDom patch;
+            m_instanceToTemplateInterface->GeneratePatch(patch, beforeState, afterState);
+            m_instanceToTemplateInterface->AppendEntityAliasToPatchPaths(patch, entityId);
+
+            if (patch.IsArray() && !patch.Empty() && beforeState.IsObject())
+            {
+                bool isInstanceContainerEntity = IsInstanceContainerEntity(entityId) && !IsLevelInstanceContainerEntity(entityId);
+                bool isNewParentOwnedByDifferentInstance = false;
+
+                if (beforeParentId != afterParentId)
                 {
-                    PrefabDom beforeState;
-                    m_prefabUndoCache.Retrieve(entityId, beforeState);
+                    // If the entity parent changed, verify if the owning instance changed too
+                    InstanceOptionalReference beforeOwningInstance = m_instanceEntityMapperInterface->FindOwningInstance(beforeParentId);
+                    InstanceOptionalReference afterOwningInstance = m_instanceEntityMapperInterface->FindOwningInstance(afterParentId);
 
-                    m_instanceToTemplateInterface->GenerateDomForEntity(afterState, *entity);
-
-                    PrefabDom patch;
-                    m_instanceToTemplateInterface->GeneratePatch(patch, beforeState, afterState);
-
-                    if (patch.IsArray() && !patch.Empty() && beforeState.IsObject())
+                    if (beforeOwningInstance.has_value() && afterOwningInstance.has_value() &&
+                        (&beforeOwningInstance->get() != &afterOwningInstance->get()))
                     {
-                        if (IsInstanceContainerEntity(entityId) && !IsLevelInstanceContainerEntity(entityId))
-                        {
-                            m_instanceToTemplateInterface->AppendEntityAliasToPatchPaths(patch, entityId);
-
-                            // Save these changes as patches to the link
-                            PrefabUndoLinkUpdate* linkUpdate =
-                                aznew PrefabUndoLinkUpdate(AZStd::to_string(static_cast<AZ::u64>(entityId)));
-                            linkUpdate->SetParent(parentUndoBatch);
-                            linkUpdate->Capture(patch, owningInstance->get().GetLinkId());
-
-                            linkUpdate->Redo();
-                        }
-                        else
-                        {
-                            // Update the state of the entity
-                            PrefabUndoEntityUpdate* state = aznew PrefabUndoEntityUpdate(AZStd::to_string(static_cast<AZ::u64>(entityId)));
-                            state->SetParent(parentUndoBatch);
-                            state->Capture(beforeState, afterState, entityId);
-
-                            state->Redo();
-                        }
+                        isNewParentOwnedByDifferentInstance = true;
                     }
+                }
 
-                    // Update the cache
-                    m_prefabUndoCache.Store(entityId, AZStd::move(afterState));
+                if (isInstanceContainerEntity)
+                {
+                    if (isNewParentOwnedByDifferentInstance)
+                    {
+                        Internal_HandleInstanceChange(parentUndoBatch, entity, beforeParentId, afterParentId);
+
+                        PrefabDom afterStateafterReparenting;
+                        m_instanceToTemplateInterface->GenerateDomForEntity(afterStateafterReparenting, *entity);
+
+                        PrefabDom newPatch;
+                        m_instanceToTemplateInterface->GeneratePatch(newPatch, afterState, afterStateafterReparenting);
+                        m_instanceToTemplateInterface->AppendEntityAliasToPatchPaths(newPatch, entityId);
+
+                        InstanceOptionalReference owningInstanceAfterReparenting =
+                            m_instanceEntityMapperInterface->FindOwningInstance(entityId);
+
+                        Internal_HandleContainerOverride(
+                            parentUndoBatch, entityId, newPatch, owningInstanceAfterReparenting->get().GetLinkId());
+                    }
+                    else
+                    {
+                        Internal_HandleContainerOverride(
+                            parentUndoBatch, entityId, patch, owningInstance->get().GetLinkId());
+                    }
                 }
                 else
                 {
-                    m_prefabUndoCache.PurgeCache(entityId);
+                    Internal_HandleEntityChange(parentUndoBatch, entityId, beforeState, afterState);
+
+                    if (isNewParentOwnedByDifferentInstance)
+                    {
+                        Internal_HandleInstanceChange(parentUndoBatch, entity, beforeParentId, afterParentId);
+                    }
                 }
             }
+
+            m_prefabUndoCache.UpdateCache(entityId);
+        }
+
+        void PrefabPublicHandler::Internal_HandleContainerOverride(
+            UndoSystem::URSequencePoint* undoBatch, AZ::EntityId entityId, const PrefabDom& patch, const LinkId linkId)
+        {
+            // Save these changes as patches to the link
+            PrefabUndoLinkUpdate* linkUpdate = aznew PrefabUndoLinkUpdate(AZStd::to_string(static_cast<AZ::u64>(entityId)));
+            linkUpdate->SetParent(undoBatch);
+            linkUpdate->Capture(patch, linkId);
+
+            linkUpdate->Redo();
+        }
+
+        void PrefabPublicHandler::Internal_HandleEntityChange(
+            UndoSystem::URSequencePoint* undoBatch, AZ::EntityId entityId, PrefabDom& beforeState, PrefabDom& afterState)
+        {
+            // Update the state of the entity
+            PrefabUndoEntityUpdate* state = aznew PrefabUndoEntityUpdate(AZStd::to_string(static_cast<AZ::u64>(entityId)));
+            state->SetParent(undoBatch);
+            state->Capture(beforeState, afterState, entityId);
+
+            state->Redo();
+        }
+
+        void PrefabPublicHandler::Internal_HandleInstanceChange(
+            UndoSystem::URSequencePoint* undoBatch, AZ::Entity* entity, AZ::EntityId beforeParentId, AZ::EntityId afterParentId)
+        {
+            // If the entity parent changed, verify if the owning instance changed too
+            InstanceOptionalReference beforeOwningInstance = m_instanceEntityMapperInterface->FindOwningInstance(beforeParentId);
+            InstanceOptionalReference afterOwningInstance = m_instanceEntityMapperInterface->FindOwningInstance(afterParentId);
+
+            EntityList entities;
+            AZStd::vector<Instance*> instances;
+
+            // Retrieve all descendant entities and instances of this entity that belonged to the same owning instance.
+            RetrieveAndSortPrefabEntitiesAndInstances({ entity }, beforeOwningInstance->get(), entities, instances);
+
+            AZStd::vector<AZStd::unique_ptr<Instance>> instanceUniquePtrs;
+            AZStd::vector<AZStd::pair<Instance*, PrefabDom>> instancePatches;
+
+            // Remove Entities and Instances from the prior instance
+            {
+                // Remove Instances
+                for (Instance* nestedInstance : instances)
+                {
+                    auto linkRef = m_prefabSystemComponentInterface->FindLink(nestedInstance->GetLinkId());
+
+                    PrefabDom oldLinkPatches;
+
+                    if (linkRef.has_value())
+                    {
+                        auto patches = linkRef->get().GetLinkPatches();
+                        if (patches.has_value())
+                        {
+                            oldLinkPatches.CopyFrom(patches->get(), oldLinkPatches.GetAllocator());
+                        }
+                    }
+
+                    auto nestedInstanceUniquePtr = beforeOwningInstance->get().DetachNestedInstance(nestedInstance->GetInstanceAlias());
+                    RemoveLink(nestedInstanceUniquePtr, beforeOwningInstance->get().GetTemplateId(), undoBatch);
+
+                    instancePatches.emplace_back(AZStd::make_pair(nestedInstanceUniquePtr.get(), AZStd::move(oldLinkPatches)));
+                    instanceUniquePtrs.emplace_back(AZStd::move(nestedInstanceUniquePtr));
+                }
+
+                // Get the previous state of the prior instance for undo/redo purposes
+                PrefabDom beforeInstanceDomBeforeRemoval;
+                m_instanceToTemplateInterface->GenerateDomForInstance(beforeInstanceDomBeforeRemoval, beforeOwningInstance->get());
+
+                // Remove Entities
+                for (AZ::Entity* nestedEntity : entities)
+                {
+                    beforeOwningInstance->get().DetachEntity(nestedEntity->GetId()).release();
+                }
+
+                // Create the Update node for the prior owning instance
+                // Instance removal will be taken care of from the RemoveLink function for undo/redo purposes
+                PrefabUndoHelpers::UpdatePrefabInstance(
+                    beforeOwningInstance->get(), "Update prior prefab instance", beforeInstanceDomBeforeRemoval, undoBatch);
+            }
+
+            // Add Entities and Instances to new instance
+            {
+                // Add Instances
+                for (auto& instanceUniquePtr : instanceUniquePtrs)
+                {
+                    afterOwningInstance->get().AddInstance(AZStd::move(instanceUniquePtr));
+                }
+
+                // Create Links
+                for (auto& instanceInfo : instancePatches)
+                {
+                    // Add a new link with the old dom
+                    CreateLink(
+                        *instanceInfo.first, afterOwningInstance->get().GetTemplateId(), undoBatch,
+                        AZStd::move(instanceInfo.second));
+                }
+
+                // Get the previous state of the new instance for undo/redo purposes
+                PrefabDom afterInstanceDomBeforeAdd;
+                m_instanceToTemplateInterface->GenerateDomForInstance(afterInstanceDomBeforeAdd, afterOwningInstance->get());
+
+                // Add Entities
+                for (AZ::Entity* nestedEntity : entities)
+                {
+                    afterOwningInstance->get().AddEntity(*nestedEntity);
+                }
+
+                // Create the Update node for the new owning instance
+                PrefabUndoHelpers::UpdatePrefabInstance(
+                    afterOwningInstance->get(), "Update new prefab instance", afterInstanceDomBeforeAdd, undoBatch);
+            }
         }
 
         bool PrefabPublicHandler::IsInstanceContainerEntity(AZ::EntityId entityId) const
@@ -748,16 +899,29 @@ namespace AzToolsFramework
 
             if (!EntitiesBelongToSameInstance(entityIds))
             {
-                return AZ::Failure(AZStd::string("Cannot duplicate multiple "
-                    "entities belonging to different instances with one operation."));
+                return AZ::Failure(AZStd::string("Cannot duplicate multiple entities belonging to different instances with one operation."
+                    "Change your selection to contain entities in the same instance."));
             }
 
             // We've already verified the entities are all owned by the same instance,
             // so we can just retrieve our instance from the first entity in the list.
-            InstanceOptionalReference commonEntityOwningInstance = GetOwnerInstanceByEntityId(entityIds[0]);
-            AZ_Assert(
-                commonEntityOwningInstance.has_value(),
-                "Failed to duplicate : Couldn't get a valid owning instance for the common root entity of the entities provided");
+            AZ::EntityId firstEntityIdToDuplicate = entityIds[0];
+            InstanceOptionalReference commonOwningInstance = GetOwnerInstanceByEntityId(firstEntityIdToDuplicate);
+            if (!commonOwningInstance.has_value())
+            {
+                return AZ::Failure(AZStd::string("Failed to duplicate : Couldn't get a valid owning instance for the common root entity of the entities provided."));
+            }
+
+            // If the first entity id is a container entity id, then we need to mark its parent as the common owning instance because you
+            // cannot duplicate an instance from itself.
+            if (commonOwningInstance->get().GetContainerEntityId() == firstEntityIdToDuplicate)
+            {
+                commonOwningInstance = commonOwningInstance->get().GetParentInstance();
+            }
+            if (!commonOwningInstance.has_value())
+            {
+                return AZ::Failure(AZStd::string("Failed to duplicate : Couldn't get a valid owning instance for the common root entity of the entities provided."));
+            }
 
             // This will cull out any entities that have ancestors in the list, since we will end up duplicating
             // the full nested hierarchy with what is returned from RetrieveAndSortPrefabEntitiesAndInstances
@@ -770,105 +934,63 @@ namespace AzToolsFramework
             {
                 AZ_PROFILE_SCOPE(AZ::Debug::ProfileCategory::AzToolsFramework, "DuplicateEntitiesInInstance::UndoCaptureAndDuplicateEntities");
 
-                // Take a snapshot of the instance DOM before we manipulate it
-                Prefab::PrefabDom instanceDomBefore;
-                m_instanceToTemplateInterface->GenerateDomForInstance(instanceDomBefore, commonEntityOwningInstance->get());
-
                 AZStd::vector<AZ::Entity*> entities;
                 AZStd::vector<Instance*> instances;
 
-                // Gather all entities/instances in the hierarchy, but don't detach them because we are duplicating not deleting.
                 EntityList inputEntityList = EntityIdSetToEntityList(duplicationSet);
-                bool success = RetrieveAndSortPrefabEntitiesAndInstances(inputEntityList, commonEntityOwningInstance->get(), entities, instances);
+                bool success = RetrieveAndSortPrefabEntitiesAndInstances(inputEntityList, commonOwningInstance->get(), entities, instances);
 
                 if (!success)
                 {
                     return AZ::Failure(AZStd::string("Failed to retrieve entities and instances from the given list of entity ids for duplication"));
                 }
 
-                // Make a copy of our before instance DOM where we will add our duplicated entities
-                Prefab::PrefabDom instanceDomAfter;
+                // Take a snapshot of the instance DOM before we manipulate it
+                PrefabDom instanceDomBefore;
+                m_instanceToTemplateInterface->GenerateDomForInstance(instanceDomBefore, commonOwningInstance->get());
+
+                // Make a copy of our before instance DOM where we will add our duplicated entities and/or instances
+                PrefabDom instanceDomAfter;
                 instanceDomAfter.CopyFrom(instanceDomBefore, instanceDomAfter.GetAllocator());
 
-                AZStd::unordered_map<EntityAlias, EntityAlias> oldAliasToNewAliasMap;
-                AZStd::unordered_map<EntityAlias, QString> aliasToEntityDomMap;
+                EntityIdList duplicatedEntityAndInstanceIds;
 
-                for (AZ::Entity* entity : entities)
-                {
-                    EntityAliasOptionalReference oldAliasRef = commonEntityOwningInstance->get().GetEntityAlias(entity->GetId());
-                    AZ_Assert(oldAliasRef.has_value(), "No alias found for Entity in the DOM");
-                    EntityAlias oldAlias = oldAliasRef.value();
+                // Duplicate any nested entities and instances as requested
+                AZStd::unordered_map<InstanceAlias, Instance*> newInstanceAliasToOldInstanceMap;
+                DuplicateNestedEntitiesInInstance(commonOwningInstance->get(),
+                    entities, instanceDomAfter, duplicatedEntityAndInstanceIds);
+                DuplicateNestedInstancesInInstance(commonOwningInstance->get(),
+                    instances, instanceDomAfter, duplicatedEntityAndInstanceIds,
+                    newInstanceAliasToOldInstanceMap);
 
-                    // Give this the outer allocator so that the memory reference will be valid when
-                    // it gets used for AddMember
-                    Prefab::PrefabDom entityDomBefore(&instanceDomAfter.GetAllocator());
-                    m_instanceToTemplateInterface->GenerateDomForEntity(entityDomBefore, *entity);
-
-                    // Keep track of the old alias <-> new alias mapping for this duplicated entity
-                    // so we can fixup references later
-                    EntityAlias newEntityAlias = Instance::GenerateEntityAlias();
-                    oldAliasToNewAliasMap.insert(AZStd::make_pair(oldAlias, newEntityAlias));
-
-                    rapidjson::StringBuffer buffer;
-                    rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
-                    entityDomBefore.Accept(writer);
-
-                    // Store our duplicated Entity DOM with its new alias as a string
-                    // so that we can fixup entity alias references before adding it
-                    // to the Entities member of our instance DOM
-                    QString entityDomString(buffer.GetString());
-                    aliasToEntityDomMap.insert(AZStd::make_pair(newEntityAlias, entityDomString));
-                }
-
-                auto entitiesIter = instanceDomAfter.FindMember(PrefabDomUtils::EntitiesName);
-                AZ_Assert(entitiesIter != instanceDomAfter.MemberEnd(), "Instance DOM missing the Entities member.");
-
-                // Now that all the duplicated Entity DOMs have been created, we need to iterate
-                // through them and replace any previous EntityAlias references with the new ones.
-                // These are more than just parent entity references for nested entities, this will
-                // also cover any EntityId references that were made in the components between them.
-                for (auto aliasEntityPair : aliasToEntityDomMap)
-                {
-                    EntityAlias newEntityAlias = aliasEntityPair.first;
-                    QString newEntityDomString = aliasEntityPair.second;
-
-                    // Replace all of the old alias references with the new ones
-                    // We bookend the aliases with \" and also with a / as an extra precaution to prevent
-                    // inadvertently replacing a matching string vs. where an actual EntityId is expected
-                    // This will cover both cases where an alias could be used in a normal entity vs. an instance
-                    for (auto aliasMapIter : oldAliasToNewAliasMap)
-                    {
-                        ReplaceOldAliases(newEntityDomString, aliasMapIter.first, aliasMapIter.second);
-                    }
-
-                    // Create the new Entity DOM from parsing the JSON string
-                    Prefab::PrefabDom entityDomAfter(&instanceDomAfter.GetAllocator());
-                    entityDomAfter.Parse(newEntityDomString.toUtf8().constData());
-
-                    // Add the new Entity DOM to the Entities member of the instance
-                    rapidjson::Value aliasName(newEntityAlias.c_str(), newEntityAlias.length(), instanceDomAfter.GetAllocator());
-                    entitiesIter->value.AddMember(AZStd::move(aliasName), entityDomAfter, instanceDomAfter.GetAllocator());
-                }
-
-                PrefabUndoInstance* command = aznew PrefabUndoInstance("Entity duplication");
+                PrefabUndoInstance* command = aznew PrefabUndoInstance("Entity/Instance duplication");
                 command->SetParent(undoBatch.GetUndoBatch());
-                command->Capture(instanceDomBefore, instanceDomAfter, commonEntityOwningInstance->get().GetTemplateId());
-                command->RunRedo();
+                command->Capture(instanceDomBefore, instanceDomAfter, commonOwningInstance->get().GetTemplateId());
+                command->Redo();
 
-                EntityIdList duplicatedEntityIds;
-                for (auto aliasMapIter : oldAliasToNewAliasMap)
+                // Create links for our duplicated instances (if any were duplicated)
+                for (auto [newInstanceAlias, oldInstance] : newInstanceAliasToOldInstanceMap)
                 {
-                    EntityAlias newEntityAlias = aliasMapIter.second;
+                    LinkId oldLinkId = oldInstance->GetLinkId();
+                    auto linkRef = m_prefabSystemComponentInterface->FindLink(oldLinkId);
+                    AZ_Assert(
+                        linkRef.has_value(), "Unable to find link with id '%llu' during instance duplication.",
+                        oldLinkId);
 
-                    AliasPath absoluteEntityPath = commonEntityOwningInstance->get().GetAbsoluteInstanceAliasPath();
-                    absoluteEntityPath.Append(newEntityAlias);
+                    PrefabDomValueReference linkPatches = linkRef->get().GetLinkPatches();
+                    AZ_Assert(
+                        linkPatches.has_value(), "Link with id '%llu' is missing patches.",
+                        oldLinkId);
 
-                    AZ::EntityId newEntityId = InstanceEntityIdMapper::GenerateEntityIdForAliasPath(absoluteEntityPath);
-                    duplicatedEntityIds.push_back(newEntityId);
+                    PrefabDom linkPatchesCopy;
+                    linkPatchesCopy.CopyFrom(linkPatches->get(), linkPatchesCopy.GetAllocator());
+
+                    m_prefabSystemComponentInterface->CreateLink(
+                        commonOwningInstance->get().GetTemplateId(), oldInstance->GetTemplateId(), newInstanceAlias, linkPatchesCopy);
                 }
 
-                // Select the duplicated entities
-                auto selectionUndo = aznew SelectionCommand(duplicatedEntityIds, "Select Duplicated Entities");
+                // Select the duplicated entities/instances
+                auto selectionUndo = aznew SelectionCommand(duplicatedEntityAndInstanceIds, "Select Duplicated Entities/Instances");
                 selectionUndo->SetParent(undoBatch.GetUndoBatch());
                 ToolsApplicationRequestBus::Broadcast(&ToolsApplicationRequestBus::Events::RunRedoSeparately, selectionUndo);
             }
@@ -989,6 +1111,123 @@ namespace AzToolsFramework
             return AZ::Success();
         }
 
+        PrefabOperationResult PrefabPublicHandler::DetachPrefab(const AZ::EntityId& containerEntityId)
+        {
+            if (!containerEntityId.IsValid())
+            {
+                return AZ::Failure(AZStd::string("Cannot detach Prefab Instance with invalid container entity."));
+            }
+
+            if (IsLevelInstanceContainerEntity(containerEntityId))
+            {
+                return AZ::Failure(AZStd::string("Cannot detach level Prefab Instance."));
+            }
+
+            InstanceOptionalReference owningInstance = GetOwnerInstanceByEntityId(containerEntityId);
+            if (owningInstance->get().GetContainerEntityId() != containerEntityId)
+            {
+                return AZ::Failure(AZStd::string("Input entity should be its owning Instance's container entity."));
+            }
+
+            AZ_PROFILE_FUNCTION(AZ::Debug::ProfileCategory::AzToolsFramework);
+
+            {
+                AZ_PROFILE_SCOPE(AZ::Debug::ProfileCategory::AzToolsFramework, "Internal::DetachPrefab:UndoCapture");
+
+                ScopedUndoBatch undoBatch("Detach Prefab");
+
+                InstanceOptionalReference getParentInstanceResult = owningInstance->get().GetParentInstance();
+                AZ_Assert(getParentInstanceResult.has_value(), "Can't get parent Instance from Instance of given container entity.");
+
+                auto& parentInstance = getParentInstanceResult->get();
+                const auto parentTemplateId = parentInstance.GetTemplateId();
+
+                {
+                    auto instancePtr = parentInstance.DetachNestedInstance(owningInstance->get().GetInstanceAlias());
+                    AZ_Assert(instancePtr, "Can't detach selected Instance from its parent Instance.");
+
+                    RemoveLink(instancePtr, parentTemplateId, undoBatch.GetUndoBatch());
+
+                    Prefab::PrefabDom instanceDomBefore;
+                    m_instanceToTemplateInterface->GenerateDomForInstance(instanceDomBefore, parentInstance);
+
+                    AZStd::unordered_map<AZ::EntityId, AZStd::string> oldEntityAliases;
+                    oldEntityAliases.emplace(containerEntityId, instancePtr->GetEntityAlias(containerEntityId)->get());
+
+                    auto containerEntityPtr = instancePtr->DetachContainerEntity();
+                    auto& containerEntity = *containerEntityPtr.release();
+                    auto editorPrefabComponent = containerEntity.FindComponent<EditorPrefabComponent>();
+                    containerEntity.Deactivate();
+                    const bool editorPrefabComponentRemoved = containerEntity.RemoveComponent(editorPrefabComponent);
+                    AZ_Assert(editorPrefabComponentRemoved, "Remove EditorPrefabComponent failed.");
+                    delete editorPrefabComponent;
+                    containerEntity.Activate();
+
+                    const bool containerEntityAdded = parentInstance.AddEntity(containerEntity);
+                    AZ_Assert(containerEntityAdded, "Add target Instance's container entity to its parent Instance failed.");
+
+                    EntityIdList entityIds;
+                    entityIds.emplace_back(containerEntity.GetId());
+
+                    instancePtr->GetEntities(
+                        [&](AZStd::unique_ptr<AZ::Entity>& entityPtr)
+                    {
+                        oldEntityAliases.emplace(entityPtr->GetId(), instancePtr->GetEntityAlias(entityPtr->GetId())->get());
+                        return true;
+                    });
+
+                    instancePtr->DetachEntities(
+                        [&](AZStd::unique_ptr<AZ::Entity> entityPtr)
+                    {
+                        auto& entity = *entityPtr.release();
+                        const bool entityAdded = parentInstance.AddEntity(entity);
+                        AZ_Assert(entityAdded, "Add target Instance's entity to its parent Instance failed.");
+
+                        entityIds.emplace_back(entity.GetId());
+                    });
+
+                    Prefab::PrefabDom instanceDomAfter;
+                    m_instanceToTemplateInterface->GenerateDomForInstance(instanceDomAfter, parentInstance);
+
+                    PrefabUndoInstance* command = aznew PrefabUndoInstance("Instance detachment");
+                    command->Capture(instanceDomBefore, instanceDomAfter, parentTemplateId);
+                    command->SetParent(undoBatch.GetUndoBatch());
+                    {
+                        AZ_PROFILE_SCOPE(AZ::Debug::ProfileCategory::AzToolsFramework, "Internal::DetachPrefab:RunRedo");
+                        command->RunRedo();
+                    }
+
+                    const auto instanceTemplateId = instancePtr->GetTemplateId();
+                    auto parentContainerEntityId = parentInstance.GetContainerEntityId();
+                    instancePtr->GetNestedInstances(
+                        [&](AZStd::unique_ptr<Instance>& nestedInstancePtr)
+                    {
+                        //get previous link patch
+                        auto linkRef = m_prefabSystemComponentInterface->FindLink(nestedInstancePtr->GetLinkId());
+                        PrefabDomValueReference linkPatches = linkRef->get().GetLinkPatches();
+                        AZ_Assert(
+                            linkPatches.has_value(), "Unable to get patches on link with id '%llu' during prefab creation.",
+                            nestedInstancePtr->GetLinkId());
+
+                        PrefabDom linkPatchesCopy;
+                        linkPatchesCopy.CopyFrom(linkPatches->get(), linkPatchesCopy.GetAllocator());
+
+                        RemoveLink(nestedInstancePtr, instanceTemplateId, undoBatch.GetUndoBatch());
+
+                        UpdateLinkPatchesWithNewEntityAliases(linkPatchesCopy, oldEntityAliases, parentInstance);
+                        
+                        CreateLink(*nestedInstancePtr, parentTemplateId, undoBatch.GetUndoBatch(),
+                            AZStd::move(linkPatchesCopy), true);
+                    });
+                }
+
+                AzToolsFramework::ToolsApplicationRequestBus::Broadcast(
+                    &AzToolsFramework::ToolsApplicationRequestBus::Events::ClearDirtyEntities);
+            }
+
+            return AZ::Success();
+        }
+
         void PrefabPublicHandler::GenerateContainerEntityTransform(const EntityList& topLevelEntities,
             AZ::Vector3& translation, AZ::Quaternion& rotation)
         {
@@ -1240,8 +1479,159 @@ namespace AzToolsFramework
             return true;
         }
 
+        void PrefabPublicHandler::DuplicateNestedEntitiesInInstance(Instance& commonOwningInstance,
+            const AZStd::vector<AZ::Entity*>& entities, PrefabDom& domToAddDuplicatedEntitiesUnder,
+            EntityIdList& duplicatedEntityIds)
+        {
+            if (entities.empty())
+            {
+                return;
+            }
+
+            AZStd::unordered_map<EntityAlias, EntityAlias> oldAliasToNewAliasMap;
+            AZStd::unordered_map<EntityAlias, QString> aliasToEntityDomMap;
+
+            for (AZ::Entity* entity : entities)
+            {
+                EntityAliasOptionalReference oldAliasRef = commonOwningInstance.GetEntityAlias(entity->GetId());
+                AZ_Assert(oldAliasRef.has_value(), "No alias found for Entity in the DOM");
+                EntityAlias oldAlias = oldAliasRef.value();
+
+                // Give this the outer allocator so that the memory reference will be valid when
+                // it gets used for AddMember
+                PrefabDom entityDomBefore(&domToAddDuplicatedEntitiesUnder.GetAllocator());
+                m_instanceToTemplateInterface->GenerateDomForEntity(entityDomBefore, *entity);
+
+                // Keep track of the old alias <-> new alias mapping for this duplicated entity
+                // so we can fixup references later
+                EntityAlias newEntityAlias = Instance::GenerateEntityAlias();
+                oldAliasToNewAliasMap.emplace(oldAlias, newEntityAlias);
+
+                rapidjson::StringBuffer buffer;
+                rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
+                entityDomBefore.Accept(writer);
+
+                // Store our duplicated Entity DOM with its new alias as a string
+                // so that we can fixup entity alias references before adding it
+                // to the Entities member of our instance DOM
+                QString entityDomString(buffer.GetString());
+                aliasToEntityDomMap.emplace(newEntityAlias, entityDomString);
+            }
+
+            auto entitiesIter = domToAddDuplicatedEntitiesUnder.FindMember(PrefabDomUtils::EntitiesName);
+            AZ_Assert(entitiesIter != domToAddDuplicatedEntitiesUnder.MemberEnd(), "Instance DOM missing the Entities member.");
+
+            // Now that all the duplicated Entity DOMs have been created, we need to iterate
+            // through them and replace any previous EntityAlias references with the new ones.
+            // These are more than just parent entity references for nested entities, this will
+            // also cover any EntityId references that were made in the components between them.
+            for (auto [newEntityAlias, newEntityDomString] : aliasToEntityDomMap)
+            {
+                // Replace all of the old alias references with the new ones
+                for (auto [oldAlias, newAlias] : oldAliasToNewAliasMap)
+                {
+                    ReplaceOldAliases(newEntityDomString, oldAlias, newAlias);
+                }
+
+                // Create the new Entity DOM from parsing the JSON string
+                PrefabDom entityDomAfter(&domToAddDuplicatedEntitiesUnder.GetAllocator());
+                entityDomAfter.Parse(newEntityDomString.toUtf8().constData());
+
+                // Add the new Entity DOM to the Entities member of the instance
+                rapidjson::Value aliasName(newEntityAlias.c_str(), newEntityAlias.length(), domToAddDuplicatedEntitiesUnder.GetAllocator());
+                entitiesIter->value.AddMember(AZStd::move(aliasName), entityDomAfter, domToAddDuplicatedEntitiesUnder.GetAllocator());
+            }
+
+            for (auto aliasMapIter : oldAliasToNewAliasMap)
+            {
+                EntityAlias newEntityAlias = aliasMapIter.second;
+
+                AliasPath absoluteEntityPath = commonOwningInstance.GetAbsoluteInstanceAliasPath();
+                absoluteEntityPath.Append(newEntityAlias);
+
+                AZ::EntityId newEntityId = InstanceEntityIdMapper::GenerateEntityIdForAliasPath(absoluteEntityPath);
+                duplicatedEntityIds.push_back(newEntityId);
+            }
+        }
+
+        void PrefabPublicHandler::DuplicateNestedInstancesInInstance(Instance& commonOwningInstance,
+            const AZStd::vector<Instance*>& instances, PrefabDom& domToAddDuplicatedInstancesUnder,
+            EntityIdList& duplicatedEntityIds, AZStd::unordered_map<InstanceAlias, Instance*>& newInstanceAliasToOldInstanceMap)
+        {
+            if (instances.empty())
+            {
+                return;
+            }
+
+            AZStd::unordered_map<InstanceAlias, InstanceAlias> oldInstanceAliasToNewInstanceAliasMap;
+            AZStd::unordered_map<InstanceAlias, QString> aliasToInstanceDomMap;
+
+            for (auto instance : instances)
+            {
+                PrefabDom nestedInstanceDomBefore;
+                m_instanceToTemplateInterface->GenerateDomForInstance(nestedInstanceDomBefore, *instance);
+
+                // Keep track of the old alias <-> new alias mapping for this duplicated instance
+                // so we can fixup references later
+                InstanceAlias oldAlias = instance->GetInstanceAlias();
+                InstanceAlias newInstanceAlias = Instance::GenerateInstanceAlias();
+                oldInstanceAliasToNewInstanceAliasMap.emplace(oldAlias, newInstanceAlias);
+
+                // Keep track of our new instance alias with the Instance it was duplicated from,
+                // so that after all instances are duplicated, we can go back and create links for them
+                newInstanceAliasToOldInstanceMap.emplace(newInstanceAlias, instance);
+
+                rapidjson::StringBuffer buffer;
+                rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
+                nestedInstanceDomBefore.Accept(writer);
+
+                // Store our duplicated Instance DOM with its new alias as a string
+                // so that we can fixup instance alias references before adding it
+                // to the Instances member of our instance DOM
+                QString instanceDomString(buffer.GetString());
+                aliasToInstanceDomMap.emplace(newInstanceAlias, instanceDomString);
+            }
+
+            auto instancesIter = domToAddDuplicatedInstancesUnder.FindMember(PrefabDomUtils::InstancesName);
+            AZ_Assert(instancesIter != domToAddDuplicatedInstancesUnder.MemberEnd(), "Instance DOM missing the Instances member.");
+
+            // Now that all the duplicated Instance DOMs have been created, we need to iterate
+            // through them and replace any previous InstanceAlias references with the new ones.
+            for (auto [newInstanceAlias, newInstanceDomString]: aliasToInstanceDomMap)
+            {
+                // Replace all of the old alias references with the new ones
+                for (auto [oldAlias, newAlias] : oldInstanceAliasToNewInstanceAliasMap)
+                {
+                    ReplaceOldAliases(newInstanceDomString, oldAlias, newAlias);
+                }
+
+                // Create the new Instance DOM from parsing the JSON string
+                PrefabDom nestedInstanceDomAfter(&domToAddDuplicatedInstancesUnder.GetAllocator());
+                nestedInstanceDomAfter.Parse(newInstanceDomString.toUtf8().constData());
+
+                // Add the new Instance DOM to the Instances member of the instance
+                rapidjson::Value aliasName(newInstanceAlias.c_str(), newInstanceAlias.length(), domToAddDuplicatedInstancesUnder.GetAllocator());
+                instancesIter->value.AddMember(AZStd::move(aliasName), nestedInstanceDomAfter, domToAddDuplicatedInstancesUnder.GetAllocator());
+            }
+
+            for (auto aliasMapIter : oldInstanceAliasToNewInstanceAliasMap)
+            {
+                InstanceAlias newInstanceAlias = aliasMapIter.second;
+
+                AliasPath absoluteInstancePath = commonOwningInstance.GetAbsoluteInstanceAliasPath();
+                absoluteInstancePath.Append(newInstanceAlias);
+
+                AZ::EntityId newEntityId = InstanceEntityIdMapper::GenerateEntityIdForAliasPath(absoluteInstancePath);
+                duplicatedEntityIds.push_back(newEntityId);
+            }
+        }
+
         void PrefabPublicHandler::ReplaceOldAliases(QString& stringToReplace, AZStd::string_view oldAlias, AZStd::string_view newAlias)
         {
+            // Replace all of the old alias references with the new ones
+            // We bookend the aliases with \" and also with a / as an extra precaution to prevent
+            // inadvertently replacing a matching string vs. where an actual EntityId is expected
+            // This will cover both cases where an alias could be used in a normal entity vs. an instance
             QString oldAliasQuotes = QString("\"%1\"").arg(oldAlias.data());
             QString newAliasQuotes = QString("\"%1\"").arg(newAlias.data());
 
@@ -1252,5 +1642,30 @@ namespace AzToolsFramework
 
             stringToReplace.replace(oldAliasPathRef, newAliasPathRef);
         }
+
+        void PrefabPublicHandler::UpdateLinkPatchesWithNewEntityAliases(
+            PrefabDom& linkPatch,
+            const AZStd::unordered_map<AZ::EntityId, AZStd::string>& oldEntityAliases,
+            Instance& newParent)
+        {
+            rapidjson::StringBuffer buffer;
+            rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
+            linkPatch.Accept(writer);
+            QString previousPatchString(buffer.GetString());
+
+            for (const auto& [entityId, oldEntityAlias] : oldEntityAliases)
+            {
+                EntityAliasOptionalReference newEntityAlias = newParent.GetEntityAlias(entityId);
+                AZ_Assert(
+                    newEntityAlias.has_value(),
+                    "Could not fetch entity alias for entity with id '%llu' during prefab creation.",
+                    static_cast<AZ::u64>(entityId));
+
+                ReplaceOldAliases(previousPatchString, oldEntityAlias, newEntityAlias->get());
+            }
+
+            linkPatch.Parse(previousPatchString.toUtf8().constData());
+        }
+
     } // namespace Prefab
 } // namespace AzToolsFramework

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabPublicHandler.h

@@ -64,6 +64,8 @@ namespace AzToolsFramework
             PrefabOperationResult DeleteEntitiesAndAllDescendantsInInstance(const EntityIdList& entityIds) override;
             PrefabOperationResult DuplicateEntitiesInInstance(const EntityIdList& entityIds) override;
 
+            PrefabOperationResult DetachPrefab(const AZ::EntityId& containerEntityId) override;
+
         private:
             PrefabOperationResult DeleteFromInstance(const EntityIdList& entityIds, bool deleteDescendants);
             bool RetrieveAndSortPrefabEntitiesAndInstances(const EntityList& inputEntities, Instance& commonRootEntityOwningInstance,
@@ -71,6 +73,33 @@ namespace AzToolsFramework
 
             InstanceOptionalReference GetOwnerInstanceByEntityId(AZ::EntityId entityId) const;
             bool EntitiesBelongToSameInstance(const EntityIdList& entityIds) const;
+
+            /**
+             * Duplicate a list of entities owned by a common owning instance by directly
+             * copying/modifying their entries in the instance DOM
+             *
+             * \param commonOwningInstance The common owning instance of all the entities being duplicated.
+             * \param entities The list of Entities that will be duplicated.
+             * \param domToAddDuplicatedEntitiesUnder The DOM of the common owning instance where the duplicated
+             *      entity DOM values will be added to.
+             * \param duplicatedEntityIds A list of EntityIds corresponding to the entities that were duplicated.
+             */
+            void DuplicateNestedEntitiesInInstance(Instance& commonOwningInstance,
+                const AZStd::vector<AZ::Entity*>& entities, PrefabDom& domToAddDuplicatedEntitiesUnder,
+                EntityIdList& duplicatedEntityIds);
+            /**
+             * Duplicate a list of instances owned by a common owning instance by directly
+             * copying/modifying their entries in the instance DOM
+             *
+             * \param commonOwningInstance The common owning instance of all the instances being duplicated.
+             * \param entities The list of Instances that will be duplicated.
+             * \param domToAddDuplicatedInstancesUnder The DOM of the common owning instance where the duplicated
+             *      instance DOM values will be added to.
+             * \param duplicatedEntityIds A list of EntityIds corresponding to the instances that were duplicated.
+             */
+            void DuplicateNestedInstancesInInstance(Instance& commonOwningInstance,
+                const AZStd::vector<Instance*>& instances, PrefabDom& domToAddDuplicatedInstancesUnder,
+                EntityIdList& duplicatedEntityIds, AZStd::unordered_map<InstanceAlias, Instance*>& newInstanceAliasToOldInstanceMap);
             
             /**
              * Applies the correct transform changes to the container entity based on the parent and child entities provided, and returns an appropriate patch.
@@ -88,8 +117,8 @@ namespace AzToolsFramework
             /**
              * Creates a link between the templates of an instance and its parent.
              * 
-             * \param sourceInstance The instance that corresponds to the source template of the link.
-             * \param targetInstance The id of the target template.
+             * \param sourceInstance The instance that corresponds to the source template of the link (child).
+             * \param targetInstance The id of the target template (parent).
              * \param undoBatch The undo batch to set as parent for this create link action.
              * \param patch The patch to store in the newly created link dom.
              * \param isUndoRedoSupportNeeded The flag indicating whether the link should be created with undo/redo support or not.
@@ -132,7 +161,18 @@ namespace AzToolsFramework
             bool IsCyclicalDependencyFound(
                 InstanceOptionalConstReference instance, const AZStd::unordered_set<AZ::IO::Path>& templateSourcePaths);
 
-            void ReplaceOldAliases(QString& stringToReplace, AZStd::string_view oldAlias, AZStd::string_view newAlias);
+            static void Internal_HandleContainerOverride(
+                UndoSystem::URSequencePoint* undoBatch, AZ::EntityId entityId, const PrefabDom& patch, const LinkId linkId);
+            static void Internal_HandleEntityChange(
+                UndoSystem::URSequencePoint* undoBatch, AZ::EntityId entityId, PrefabDom& beforeState, PrefabDom& afterState);
+            void Internal_HandleInstanceChange(UndoSystem::URSequencePoint* undoBatch, AZ::Entity* entity, AZ::EntityId beforeParentId, AZ::EntityId afterParentId);
+
+            void UpdateLinkPatchesWithNewEntityAliases(
+                PrefabDom& linkPatch,
+                const AZStd::unordered_map<AZ::EntityId, AZStd::string>& oldEntityAliases,
+                Instance& newParent);
+
+            static void ReplaceOldAliases(QString& stringToReplace, AZStd::string_view oldAlias, AZStd::string_view newAlias);
 
             static Instance* GetParentInstance(Instance* instance);
             static Instance* GetAncestorOfInstanceThatIsChildOfRoot(const Instance* ancestor, Instance* descendant);

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabPublicInterface.h

@@ -150,6 +150,17 @@ namespace AzToolsFramework
               * @return An outcome object; on failure, it comes with an error message detailing the cause of the error.
               */
             virtual PrefabOperationResult DuplicateEntitiesInInstance(const EntityIdList& entityIds) = 0;
+
+            /**
+              * If the entity id is a container entity id, detaches the prefab instance corresponding to it. This includes converting
+              * the container entity into a regular entity and putting it under the parent prefab, removing the link between this
+              * instance and the parent, removing links between this instance and it's nested instances, adding entities directly 
+              * owned by this instance under the parent instance.
+              * Bails if the entity is not a container entity or belongs to the level prefab instance.
+              * @param containerEntityId The container entity id of the instance to detach.
+              * @return An outcome object; on failure, it comes with an error message detailing the cause of the error.
+              */
+            virtual PrefabOperationResult DetachPrefab(const AZ::EntityId& containerEntityId) = 0;
         };
 
     } // namespace Prefab

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabSystemComponent.cpp

@@ -652,7 +652,8 @@ namespace AzToolsFramework
             if (instancesValue->get().FindMember(rapidjson::StringRef(instanceAlias.c_str())) == instancesValue->get().MemberEnd())
             {
                 instancesValue->get().AddMember(
-                    rapidjson::StringRef(instanceAlias.c_str()), PrefabDomValue(), targetTemplateDom.GetAllocator());
+                    rapidjson::Value(instanceAlias.c_str(), targetTemplateDom.GetAllocator()), PrefabDomValue(),
+                    targetTemplateDom.GetAllocator());
             }
 
             Template& sourceTemplate = sourceTemplateRef->get();
@@ -705,14 +706,14 @@ namespace AzToolsFramework
                 "Prefab - PrefabSystemComponent::RemoveLink - "
                 "Failed to remove Link with Id '%llu' for Instance '%s' of source Template with Id '%llu' "
                 "from TemplateToLinkIdsMap.",
-                linkId, link.GetSourceTemplateId(), link.GetInstanceName().c_str());
+                linkId, link.GetInstanceName().c_str(), link.GetSourceTemplateId());
 
             result = RemoveLinkFromTargetTemplate(linkId, link);
             AZ_Assert(result,
                 "Prefab - PrefabSystemComponent::RemoveLink - "
                 "Failed to remove Link with Id '%llu' for Instance '%s' of source Template with Id '%llu' "
                 "from target Template with Id '%llu'.",
-                linkId, link.GetSourceTemplateId(), link.GetInstanceName().c_str(), link.GetTargetTemplateId());
+                linkId, link.GetInstanceName().c_str(), link.GetSourceTemplateId(), link.GetTargetTemplateId());
 
             m_linkIdMap.erase(linkId);
 

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabUndoCache.cpp

@@ -73,14 +73,16 @@ namespace AzToolsFramework
             }
 
             PrefabDom oldData;
-            Retrieve(entityId, oldData);
+            AZ::EntityId oldParentId;
+            Retrieve(entityId, oldData, oldParentId);
 
             UpdateCache(entityId);
 
             PrefabDom newData;
-            Retrieve(entityId, newData);
+            AZ::EntityId newParentId;
+            Retrieve(entityId, newData, newParentId);
 
-            if (newData != oldData)
+            if (newData != oldData || oldParentId != newParentId)
             {
                 // display a useful message
                 AZ::Entity* entity = nullptr;
@@ -106,7 +108,7 @@ namespace AzToolsFramework
             // Clear out newly generated data and
             // replace with original data to ensure debug mode has the same data as profile/release
             // in the event of the consistency check failing.
-            m_entitySavedStates[entityId] = AZStd::move(oldData);
+            m_entitySavedStates[entityId] = {AZStd::move(oldData), oldParentId};
 
 #endif // ENABLE_UNDOCACHE_CONSISTENCY_CHECKS
         }
@@ -140,10 +142,13 @@ namespace AzToolsFramework
                 return;
             }
 
+            AZ::EntityId parentId;
+            AZ::TransformBus::EventResult(parentId, entityId, &AZ::TransformBus::Events::GetParentId);
+
             // Capture it
             PrefabDom entityDom;
             m_instanceToTemplateInterface->GenerateDomForEntity(entityDom, *entity);
-            m_entitySavedStates.emplace(AZStd::make_pair(entityId, AZStd::move(entityDom)));
+            m_entitySavedStates[entityId] = {AZStd::move(entityDom), parentId};
 
             AZLOG("Prefab Undo", "Correctly updated cache for entity of id %llu (%s)", static_cast<AZ::u64>(entityId), entity->GetName().c_str());
 
@@ -155,7 +160,7 @@ namespace AzToolsFramework
             m_entitySavedStates.erase(entityId);
         }
 
-        bool PrefabUndoCache::Retrieve(const AZ::EntityId& entityId, PrefabDom& outDom)
+        bool PrefabUndoCache::Retrieve(const AZ::EntityId& entityId, PrefabDom& outDom, AZ::EntityId& parentId)
         {
             auto it = m_entitySavedStates.find(entityId);
 
@@ -164,14 +169,15 @@ namespace AzToolsFramework
                 return false;
             }
 
-            outDom = AZStd::move(m_entitySavedStates[entityId]);
+            outDom = AZStd::move(m_entitySavedStates[entityId].dom);
+            parentId = m_entitySavedStates[entityId].parentId;
             m_entitySavedStates.erase(entityId);
             return true;
         }
 
-        void PrefabUndoCache::Store(const AZ::EntityId& entityId, PrefabDom&& dom)
+        void PrefabUndoCache::Store(const AZ::EntityId& entityId, PrefabDom&& dom, const AZ::EntityId& parentId)
         {
-            m_entitySavedStates.emplace(AZStd::make_pair(entityId, AZStd::move(dom)));
+            m_entitySavedStates[entityId] = {AZStd::move(dom), parentId};
         }
 
         void PrefabUndoCache::Clear()

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabUndoCache.h

@@ -46,14 +46,19 @@ namespace AzToolsFramework
             void Validate(const AZ::EntityId& entityId) override;
 
             // Retrieve the last known state for an entity
-            bool Retrieve(const AZ::EntityId& entityId, PrefabDom& outDom);
+            bool Retrieve(const AZ::EntityId& entityId, PrefabDom& outDom, AZ::EntityId& parentId);
 
             // Store dom as the cached state of entityId
-            void Store(const AZ::EntityId& entityId, PrefabDom&& dom);
+            void Store(const AZ::EntityId& entityId, PrefabDom&& dom, const AZ::EntityId& parentId);
 
         private:
-            typedef AZStd::unordered_map<AZ::EntityId, PrefabDom> EntityDomMap;
-            EntityDomMap m_entitySavedStates;
+            struct PrefabUndoCacheItem
+            {
+                PrefabDom dom;
+                AZ::EntityId parentId;
+            };
+            typedef AZStd::unordered_map<AZ::EntityId, PrefabUndoCacheItem> EntityCache;
+            EntityCache m_entitySavedStates;
 
             InstanceEntityMapperInterface* m_instanceEntityMapperInterface = nullptr;
             InstanceToTemplateInterface* m_instanceToTemplateInterface = nullptr;

Code/Framework/AzToolsFramework/AzToolsFramework/ToolsComponents/EditorNonUniformScaleComponentMode.cpp

@@ -37,13 +37,13 @@ namespace AzToolsFramework
                 axisLength, AzFramework::ViewportColors::XAxisColor, AzFramework::ViewportColors::YAxisColor,
                 AzFramework::ViewportColors::ZAxisColor);
 
-            auto mouseDownCallback = [this](const LinearManipulator::Action& action) {
+            auto mouseDownCallback = [this]([[maybe_unused]] const LinearManipulator::Action& action)
+            {
                 AZ::Vector3 nonUniformScale = AZ::Vector3::CreateOne();
-
                 AZ::NonUniformScaleRequestBus::EventResult(
                     nonUniformScale, m_entityComponentIdPair.GetEntityId(), &AZ::NonUniformScaleRequests::GetScale);
 
-                m_initialScale = nonUniformScale + action.m_start.m_scaleSnapOffset;
+                m_initialScale = nonUniformScale;
 
                 AZ::NonUniformScaleRequestBus::Event(
                     m_entityComponentIdPair.GetEntityId(), &AZ::NonUniformScaleRequests::SetScale, m_initialScale);
@@ -51,29 +51,37 @@ namespace AzToolsFramework
 
             m_manipulators->InstallAxisLeftMouseDownCallback(mouseDownCallback);
 
-            m_manipulators->InstallAxisMouseMoveCallback([this](const LinearManipulator::Action& action) {
-                const AZ::Vector3 scaleMultiplier =
-                    (AZ::Vector3::CreateOne() + ((action.LocalScaleOffset() * action.m_start.m_sign) / m_initialScale));
+            m_manipulators->InstallAxisMouseMoveCallback(
+                [this](const LinearManipulator::Action& action)
+                {
+                    const AZ::Vector3 scaleMultiplier =
+                        (AZ::Vector3::CreateOne() + ((action.LocalScaleOffset() * action.m_start.m_sign) / m_initialScale));
 
-                AZ::NonUniformScaleRequestBus::Event(
-                    m_entityComponentIdPair.GetEntityId(), &AZ::NonUniformScaleRequests::SetScale,
-                    (scaleMultiplier * m_initialScale).GetClamp(AZ::Vector3(AZ::MinTransformScale), AZ::Vector3(AZ::MaxTransformScale)));
-            });
+                    AZ::NonUniformScaleRequestBus::Event(
+                        m_entityComponentIdPair.GetEntityId(), &AZ::NonUniformScaleRequests::SetScale,
+                        (scaleMultiplier * m_initialScale)
+                            .GetClamp(AZ::Vector3(AZ::MinTransformScale), AZ::Vector3(AZ::MaxTransformScale)));
+                });
 
             m_manipulators->InstallUniformLeftMouseDownCallback(mouseDownCallback);
 
-            m_manipulators->InstallUniformMouseMoveCallback([this](const LinearManipulator::Action& action) {
-                const auto sumVectorElements = [](const AZ::Vector3& vec) { return vec.GetX() + vec.GetY() + vec.GetZ(); };
+            m_manipulators->InstallUniformMouseMoveCallback(
+                [this](const LinearManipulator::Action& action)
+                {
+                    const auto sumVectorElements = [](const AZ::Vector3& vec)
+                    {
+                        return vec.GetX() + vec.GetY() + vec.GetZ();
+                    };
 
-                const float minScaleMultiplier = AZ::MinTransformScale / m_initialScale.GetMinElement();
-                const float maxScaleMultiplier = AZ::MaxTransformScale / m_initialScale.GetMaxElement();
-                const float scaleMultiplier = AZ::GetClamp(
-                    1.0f + sumVectorElements(action.m_start.m_sign * action.LocalScaleOffset() / m_initialScale), minScaleMultiplier,
-                    maxScaleMultiplier);
+                    const float minScaleMultiplier = AZ::MinTransformScale / m_initialScale.GetMinElement();
+                    const float maxScaleMultiplier = AZ::MaxTransformScale / m_initialScale.GetMaxElement();
+                    const float scaleMultiplier = AZ::GetClamp(
+                        1.0f + sumVectorElements(action.m_start.m_sign * action.LocalScaleOffset() / m_initialScale), minScaleMultiplier,
+                        maxScaleMultiplier);
 
-                AZ::NonUniformScaleRequestBus::Event(
-                    m_entityComponentIdPair.GetEntityId(), &AZ::NonUniformScaleRequests::SetScale, scaleMultiplier * m_initialScale);
-            });
+                    AZ::NonUniformScaleRequestBus::Event(
+                        m_entityComponentIdPair.GetEntityId(), &AZ::NonUniformScaleRequests::SetScale, scaleMultiplier * m_initialScale);
+                });
         }
 
         NonUniformScaleComponentMode::~NonUniformScaleComponentMode()

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Prefab/PrefabIntegrationManager.cpp

@@ -237,6 +237,24 @@ namespace AzToolsFramework
             {
                 deleteAction->setDisabled(true);
             }
+
+            // Detach Prefab
+            if (selectedEntities.size() == 1)
+            {
+                AZ::EntityId selectedEntity = selectedEntities[0];
+
+                if (s_prefabPublicInterface->IsInstanceContainerEntity(selectedEntity) &&
+                    !s_prefabPublicInterface->IsLevelInstanceContainerEntity(selectedEntity))
+                {
+                    QAction* detachPrefabAction = menu->addAction(QObject::tr("Detach Prefab..."));
+                    QObject::connect(
+                        detachPrefabAction, &QAction::triggered, detachPrefabAction,
+                        [this, selectedEntity]
+                        {
+                            ContextMenu_DetachPrefab(selectedEntity);
+                        });
+                }
+            }
         }
 
         void PrefabIntegrationManager::HandleSourceFileType(AZStd::string_view sourceFilePath, AZ::EntityId parentId, AZ::Vector3 position) const
@@ -392,6 +410,17 @@ namespace AzToolsFramework
             }
         }
 
+        void PrefabIntegrationManager::ContextMenu_DetachPrefab(AZ::EntityId containerEntity)
+        {
+            PrefabOperationResult detachPrefabResult =
+                s_prefabPublicInterface->DetachPrefab(containerEntity);
+
+            if (!detachPrefabResult.IsSuccess())
+            {
+                WarnUserOfError("Detach Prefab error", detachPrefabResult.GetError());
+            }
+        }
+
         void PrefabIntegrationManager::GenerateSuggestedFilenameFromEntities(const EntityIdList& entityIds, AZStd::string& outName)
         {
             AZ_PROFILE_FUNCTION(AZ::Debug::ProfileCategory::AzToolsFramework);

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Prefab/PrefabIntegrationManager.h

@@ -93,6 +93,7 @@ namespace AzToolsFramework
             static void ContextMenu_EditPrefab(AZ::EntityId containerEntity);
             static void ContextMenu_SavePrefab(AZ::EntityId containerEntity);
             static void ContextMenu_DeleteSelected();
+            static void ContextMenu_DetachPrefab(AZ::EntityId containerEntity);
 
             // Prompt and resolve dialogs
             static bool QueryUserForPrefabSaveLocation(

Code/Framework/AzToolsFramework/AzToolsFramework/UI/PropertyEditor/EntityPropertyEditor.cpp

@@ -969,7 +969,8 @@ namespace AzToolsFramework
         {
             // Build up components to display
             SharedComponentArray sharedComponentArray;
-            BuildSharedComponentArray(sharedComponentArray, selectionEntityTypeInfo != SelectionEntityTypeInfo::OnlyStandardEntities);
+            BuildSharedComponentArray(sharedComponentArray,
+                !(selectionEntityTypeInfo == SelectionEntityTypeInfo::OnlyStandardEntities || selectionEntityTypeInfo == SelectionEntityTypeInfo::OnlyPrefabEntities));
 
             if (sharedComponentArray.size() == 0)
             {

Code/Framework/AzToolsFramework/AzToolsFramework/ViewportSelection/EditorSelectionUtil.cpp

@@ -124,4 +124,15 @@ namespace AzToolsFramework
         
         return cameraState;
     }
+
+    float GetScreenDisplayScaling(const int viewportId)
+    {
+        float scaling = 1.0f;
+        ViewportInteraction::ViewportInteractionRequestBus::EventResult(
+            scaling, viewportId,
+            &ViewportInteraction::ViewportInteractionRequestBus::Events::DeviceScalingFactor);
+
+        return scaling;
+    }
+
 } // namespace AzToolsFramework

Code/Framework/AzToolsFramework/AzToolsFramework/ViewportSelection/EditorSelectionUtil.h

@@ -60,6 +60,9 @@ namespace AzToolsFramework
     /// Wrapper for EBus call to return the CameraState for a given viewport.
     AzFramework::CameraState GetCameraState(int viewportId);
 
+    /// Wrapper for EBus call to return the DPI scaling for a given viewport.
+    float GetScreenDisplayScaling(const int viewportId);
+
     /// A utility to return the center of several points.
     /// Take several positions and store the min and max of each in
     /// turn - when all points have been added return the center/midpoint.

Code/Framework/AzToolsFramework/AzToolsFramework/ViewportSelection/EditorTransformComponentSelection.cpp

@@ -423,15 +423,14 @@ namespace AzToolsFramework
         }
     }
 
-    static void InitializeTranslationLookup(
-        EntityIdManipulators& entityIdManipulators, const AZ::Vector3& snapOffset)
+    static void InitializeTranslationLookup(EntityIdManipulators& entityIdManipulators)
     {
         AZ_PROFILE_FUNCTION(AZ::Debug::ProfileCategory::AzToolsFramework);
 
         for (auto& entityIdLookup : entityIdManipulators.m_lookups)
         {
             entityIdLookup.second.m_initial =
-                AZ::Transform::CreateTranslation(GetWorldTranslation(entityIdLookup.first) + snapOffset);
+                AZ::Transform::CreateTranslation(GetWorldTranslation(entityIdLookup.first));
         }
     }
 
@@ -820,7 +819,7 @@ namespace AzToolsFramework
             // moving with ctrl - setting override
             pivotOverrideFrame.m_translationOverride =
                 entityIdManipulators.m_manipulators->GetLocalTransform().GetTranslation();
-            InitializeTranslationLookup(entityIdManipulators, -action.LocalPositionOffset());
+            InitializeTranslationLookup(entityIdManipulators);
         }
         else
         {
@@ -1277,12 +1276,12 @@ namespace AzToolsFramework
 
         // linear
         translationManipulators->InstallLinearManipulatorMouseDownCallback(
-            [this, manipulatorEntityIds](const LinearManipulator::Action& action) mutable
+            [this, manipulatorEntityIds]([[maybe_unused]] const LinearManipulator::Action& action) mutable
         {
             // important to sort entityIds based on hierarchy order when updating transforms
             BuildSortedEntityIdVectorFromEntityIdMap(m_entityIdManipulators.m_lookups, manipulatorEntityIds->m_entityIds);
 
-            InitializeTranslationLookup(m_entityIdManipulators, action.m_start.m_positionSnapOffset);
+            InitializeTranslationLookup(m_entityIdManipulators);
 
             m_axisPreview.m_translation = m_entityIdManipulators.m_manipulators->GetLocalTransform().GetTranslation();
             m_axisPreview.m_orientation = QuaternionFromTransformNoScaling(
@@ -1302,19 +1301,19 @@ namespace AzToolsFramework
         });
 
         translationManipulators->InstallLinearManipulatorMouseUpCallback(
-            [this](const LinearManipulator::Action& /*action*/) mutable
+            [this]([[maybe_unused]] const LinearManipulator::Action& action) mutable
         {
             EndRecordManipulatorCommand();
         });
 
         // planar
         translationManipulators->InstallPlanarManipulatorMouseDownCallback(
-            [this, manipulatorEntityIds](const PlanarManipulator::Action& action)
+            [this, manipulatorEntityIds]([[maybe_unused]] const PlanarManipulator::Action& action)
         {
             // important to sort entityIds based on hierarchy order when updating transforms
             BuildSortedEntityIdVectorFromEntityIdMap(m_entityIdManipulators.m_lookups, manipulatorEntityIds->m_entityIds);
 
-            InitializeTranslationLookup(m_entityIdManipulators, action.m_start.m_snapOffset);
+            InitializeTranslationLookup(m_entityIdManipulators);
 
             m_axisPreview.m_translation = m_entityIdManipulators.m_manipulators->GetLocalTransform().GetTranslation();
             m_axisPreview.m_orientation = QuaternionFromTransformNoScaling(
@@ -1340,11 +1339,11 @@ namespace AzToolsFramework
 
         // surface
         translationManipulators->InstallSurfaceManipulatorMouseDownCallback(
-            [this, manipulatorEntityIds](const SurfaceManipulator::Action& action)
+            [this, manipulatorEntityIds]([[maybe_unused]] const SurfaceManipulator::Action& action)
         {
             BuildSortedEntityIdVectorFromEntityIdMap(m_entityIdManipulators.m_lookups, manipulatorEntityIds->m_entityIds);
 
-            InitializeTranslationLookup(m_entityIdManipulators, action.m_start.m_snapOffset);
+            InitializeTranslationLookup(m_entityIdManipulators);
 
             m_axisPreview.m_translation = m_entityIdManipulators.m_manipulators->GetLocalTransform().GetTranslation();
             m_axisPreview.m_orientation = QuaternionFromTransformNoScaling(
@@ -2471,7 +2470,17 @@ namespace AzToolsFramework
                 break;
             }
         });
-
+        
+        AddAction(
+            m_actions, { QKeySequence(Qt::Key_U) },
+            /*ID_VIEWPORTUI_VISIBLE=*/50040, "Toggle ViewportUI", "Hide/Unhide Viewport UI",
+           [this]()
+        {
+                SetViewportUiClusterVisible(m_transformModeClusterId, !m_viewportUiVisible);
+                SetViewportUiClusterVisible(m_spaceCluster.m_spaceClusterId, !m_viewportUiVisible);
+                m_viewportUiVisible = !m_viewportUiVisible;
+        });
+       
         EditorMenuRequestBus::Broadcast(&EditorMenuRequests::RestoreEditMenuToDefault);
     }
 
@@ -3316,26 +3325,16 @@ namespace AzToolsFramework
     }
 
     static void DrawManipulatorGrid(
-        AzFramework::DebugDisplayRequests& debugDisplay, const EntityIdManipulators& entityIdManipulators,
-        const float gridSize, const float localSnapping)
+        AzFramework::DebugDisplayRequests& debugDisplay, const EntityIdManipulators& entityIdManipulators, const float gridSize)
     {
         const AZ::Matrix3x3 orientation =
             AZ::Matrix3x3::CreateFromTransform(entityIdManipulators.m_manipulators->GetLocalTransform());
 
-        const AZ::Vector3 unsnappedTranslation =
+        const AZ::Vector3 translation =
             entityIdManipulators.m_manipulators->GetLocalTransform().GetTranslation();
 
-        // calculate the offset to snap by to align the manipulator to the grid
-        // note: only perform this if we are not snapping in local space
-        const AZ::Vector3 snappedOffset = !localSnapping
-            ? CalculateSnappedOffset(unsnappedTranslation, orientation.GetBasisX(), gridSize) +
-              CalculateSnappedOffset(unsnappedTranslation, orientation.GetBasisY(), gridSize)
-            : AZ::Vector3::CreateZero();
-
-        const AZ::Vector3 snappedTranslation = unsnappedTranslation + snappedOffset;
-
         DrawSnappingGrid(
-            debugDisplay, AZ::Transform::CreateFromMatrix3x3AndTranslation(orientation, snappedTranslation),
+            debugDisplay, AZ::Transform::CreateFromMatrix3x3AndTranslation(orientation, translation),
             gridSize);
     }
 
@@ -3474,7 +3473,7 @@ namespace AzToolsFramework
                 const GridSnapParameters gridSnapParams = GridSnapSettings(viewportInfo.m_viewportId);
                 if (gridSnapParams.m_gridSnap && m_entityIdManipulators.m_manipulators)
                 {
-                    DrawManipulatorGrid(debugDisplay, m_entityIdManipulators, gridSnapParams.m_gridSize, modifiers.Alt());
+                    DrawManipulatorGrid(debugDisplay, m_entityIdManipulators, gridSnapParams.m_gridSize);
                 }
             }
         }
@@ -3563,9 +3562,10 @@ namespace AzToolsFramework
         debugDisplay.SetLineWidth(1.0f);
 
         const float labelOffset = cl_viewportGizmoAxisLabelOffset;
-        const auto labelXScreenPosition = (gizmoStart + (gizmoAxisX * labelOffset)) * editorCameraState.m_viewportSize;
-        const auto labelYScreenPosition = (gizmoStart + (gizmoAxisY * labelOffset)) * editorCameraState.m_viewportSize;
-        const auto labelZScreenPosition = (gizmoStart + (gizmoAxisZ * labelOffset)) * editorCameraState.m_viewportSize;
+        const float screenScale = GetScreenDisplayScaling(viewportId);
+        const auto labelXScreenPosition = (gizmoStart + (gizmoAxisX * labelOffset)) * editorCameraState.m_viewportSize * screenScale;
+        const auto labelYScreenPosition = (gizmoStart + (gizmoAxisY * labelOffset)) * editorCameraState.m_viewportSize * screenScale;
+        const auto labelZScreenPosition = (gizmoStart + (gizmoAxisZ * labelOffset)) * editorCameraState.m_viewportSize * screenScale;
 
         // draw the label of of each axis for the gizmo
         const float labelSize = cl_viewportGizmoAxisLabelSize;

Code/Framework/AzToolsFramework/AzToolsFramework/ViewportSelection/EditorTransformComponentSelection.h

@@ -306,6 +306,7 @@ namespace AzToolsFramework
         AzFramework::ClickDetector m_clickDetector; //!< Detect different types of mouse click.
         AzFramework::CursorState m_cursorState; //!< Track the mouse position and delta movement each frame.
         SpaceCluster m_spaceCluster; //!< Related viewport ui state for controlling the current reference space.
+        bool m_viewportUiVisible = true; //!< Used to hide/show the viewport ui elements.
     };
 
     //! The ETCS (EntityTransformComponentSelection) namespace contains functions and data used exclusively by

Code/Framework/AzToolsFramework/Tests/Viewport/ViewportScreenTests.cpp

@@ -14,6 +14,7 @@
 #include <AzCore/Math/Matrix3x3.h>
 #include <AzCore/Math/Matrix4x4.h>
 #include <AzCore/Math/Transform.h>
+#include <AzCore/Math/VectorConversions.h>
 #include <AzCore/UnitTest/TestTypes.h>
 #include <AzFramework/Viewport/CameraState.h>
 #include <AzFramework/Viewport/ViewportScreen.h>
@@ -23,6 +24,15 @@
 
 namespace UnitTest
 {
+     // transform a point from normalized device coordinates to world space, and then from world space back to normalized device coordinates
+    AZ::Vector2 ScreenNDCToWorldToScreenNDC(
+        const AZ::Vector2& ndcPoint, const AzFramework::CameraState& cameraState)
+    {
+        const auto worldResult = AzFramework::ScreenNDCToWorld(ndcPoint, InverseCameraView(cameraState), InverseCameraProjection(cameraState));
+        const auto ndcResult = AzFramework::WorldToScreenNDC(worldResult, CameraView(cameraState), CameraProjection(cameraState));
+        return AZ::Vector3ToVector2(ndcResult);
+    }
+
     // transform a point from screen space to world space, and then from world space back to screen space
     AzFramework::ScreenPoint ScreenToWorldToScreen(
         const AzFramework::ScreenPoint& screenPoint, const AzFramework::CameraState& cameraState)
@@ -30,7 +40,8 @@ namespace UnitTest
         const auto worldResult = AzFramework::ScreenToWorld(screenPoint, cameraState);
         return AzFramework::WorldToScreen(worldResult, cameraState);
     }
-
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // ScreenPoint tests
     TEST(ViewportScreen, WorldToScreenAndScreenToWorldReturnsTheSameValueIdentityCameraOffsetFromOrigin)
     {
         using AzFramework::ScreenPoint;
@@ -38,8 +49,6 @@ namespace UnitTest
         const auto screenDimensions = AZ::Vector2(800.0f, 600.0f);
         const auto cameraPosition = AZ::Vector3::CreateAxisY(-10.0f);
 
-        // note: nearClip is 0.1 - the world space value returned will be aligned to the near clip
-        // plane of the camera so use that to confirm the mapping to/from is correct
         const auto cameraState = AzFramework::CreateIdentityDefaultCamera(cameraPosition, screenDimensions);
         {
             const auto expectedScreenPoint = ScreenPoint{600, 450};
@@ -81,6 +90,8 @@ namespace UnitTest
         EXPECT_EQ(resultScreenPoint, expectedScreenPoint);
     }
 
+    // note: nearClip is 0.1 - the world space value returned will be aligned to the near clip
+    // plane of the camera so use that to confirm the mapping to/from is correct
     TEST(ViewportScreen, ScreenToWorldReturnsPositionOnNearClipPlaneInWorldSpace)
     {
         using AzFramework::ScreenPoint;
@@ -94,7 +105,75 @@ namespace UnitTest
         const auto worldResult = AzFramework::ScreenToWorld(ScreenPoint{400, 300}, cameraState);
         EXPECT_THAT(worldResult, IsClose(AZ::Vector3(10.1f, 0.0f, 0.0f)));
     }
+    
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // NDC tests
+    TEST(ViewportScreen, WorldToScreenNDCAndScreenNDCToWorldReturnsTheSameValueIdentityCameraOffsetFromOrigin)
+    {
+        using NdcPoint = AZ::Vector2;
+        
+        const auto screenDimensions = AZ::Vector2(800.0f, 600.0f);
+        const auto cameraPosition = AZ::Vector3::CreateAxisY(-10.0f);
 
+        const auto cameraState = AzFramework::CreateIdentityDefaultCamera(cameraPosition, screenDimensions);
+        {
+            const auto expectedNdcPoint = NdcPoint{0.75f, 0.75f};
+            const auto resultNdcPoint = ScreenNDCToWorldToScreenNDC(expectedNdcPoint, cameraState);
+            EXPECT_THAT(resultNdcPoint, IsClose(expectedNdcPoint));
+        }
+
+        {
+            const auto expectedNdcPoint = NdcPoint{0.5f, 0.5f};
+            const auto resultNdcPoint = ScreenNDCToWorldToScreenNDC(expectedNdcPoint, cameraState);
+            EXPECT_THAT(resultNdcPoint, IsClose(expectedNdcPoint));
+        }
+
+        {
+            const auto expectedNdcPoint = NdcPoint{0.0f, 0.0f};
+            const auto resultNdcPoint = ScreenNDCToWorldToScreenNDC(expectedNdcPoint, cameraState);
+            EXPECT_THAT(resultNdcPoint, IsClose(expectedNdcPoint));
+        }
+
+        {
+            const auto expectedNdcPoint = NdcPoint{1.0f, 1.0f};
+            const auto resultNdcPoint = ScreenNDCToWorldToScreenNDC(expectedNdcPoint, cameraState);
+            EXPECT_THAT(resultNdcPoint, IsClose(expectedNdcPoint));
+        }
+    }
+
+    TEST(ViewportScreen, WorldToScreenNDCAndScreenNDCToWorldReturnsTheSameValueOrientatedCamera)
+    {
+        using NdcPoint = AZ::Vector2;
+
+        const auto screenDimensions = AZ::Vector2(800.0f, 600.0f);
+        const auto cameraTransform =
+            AZ::Transform::CreateRotationX(AZ::DegToRad(45.0f)) * AZ::Transform::CreateRotationZ(AZ::DegToRad(90.0f));
+
+        const auto cameraState = AzFramework::CreateDefaultCamera(cameraTransform, screenDimensions);
+
+        const auto expectedNdcPoint = NdcPoint{0.25f, 0.5f};
+        const auto resultNdcPoint = ScreenNDCToWorldToScreenNDC(expectedNdcPoint, cameraState);
+        EXPECT_THAT(resultNdcPoint, IsClose(expectedNdcPoint));
+    }
+
+    // note: nearClip is 0.1 - the world space value returned will be aligned to the near clip
+    // plane of the camera so use that to confirm the mapping to/from is correct
+    TEST(ViewportScreen, ScreenNDCToWorldReturnsPositionOnNearClipPlaneInWorldSpace)
+    {
+        using NdcPoint = AZ::Vector2;
+
+        const auto screenDimensions = AZ::Vector2(800.0f, 600.0f);
+        const auto cameraTransform = AZ::Transform::CreateTranslation(AZ::Vector3(10.0f, 0.0f, 0.0f)) *
+            AZ::Transform::CreateRotationZ(AZ::DegToRad(-90.0f));
+
+        const auto cameraState = AzFramework::CreateDefaultCamera(cameraTransform, screenDimensions);
+
+        const auto worldResult = AzFramework::ScreenNDCToWorld(NdcPoint{0.5f, 0.5f}, InverseCameraView(cameraState), InverseCameraProjection(cameraState));
+        EXPECT_THAT(worldResult, IsClose(AZ::Vector3(10.1f, 0.0f, 0.0f)));
+    }
+
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // ScreenVector tests
     TEST(ViewportScreen, SubstractingScreenPointGivesScreenVector)
     {
         using AzFramework::ScreenPoint;
@@ -220,6 +299,8 @@ namespace UnitTest
         EXPECT_NEAR(AzFramework::ScreenVectorLength(ScreenVector(12, 15)), 19.20937f, 0.001f);
     }
 
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // Other tests
     TEST(ViewportScreen, CanGetCameraTransformFromCameraViewAndBack)
     {
         const auto screenDimensions = AZ::Vector2(1024.0f, 768.0f);

Code/Framework/Tests/Spawnable/SpawnableEntitiesManagerTests.cpp

@@ -11,9 +11,11 @@
 */
 
 #include <AzCore/UnitTest/TestTypes.h>
+#include <AzCore/UserSettings/UserSettingsComponent.h>
 #include <AzFramework/Application/Application.h>
 #include <AzFramework/Spawnable/SpawnableAssetHandler.h>
 #include <AzFramework/Spawnable/SpawnableEntitiesManager.h>
+#include <AzFramework/Components/TransformComponent.h>
 #include <AzTest/AzTest.h>
 
 namespace UnitTest
@@ -40,6 +42,10 @@ namespace UnitTest
             m_application = new TestApplication();
             AZ::ComponentApplication::Descriptor descriptor;
             m_application->Start(descriptor);
+            // Without this, the user settings component would attempt to save on finalize/shutdown. Since the file is
+            // shared across the whole engine, if multiple tests are run in parallel, the saving could cause a crash
+            // in the unit tests.
+            AZ::UserSettingsComponentRequestBus::Broadcast(&AZ::UserSettingsComponentRequests::DisableSaveOnFinalize);
             
             m_spawnable = aznew AzFramework::Spawnable(
                 AZ::Data::AssetId::CreateString("{EB2E8A2B-F253-4A90-BBF4-55F2EED786B8}:0"), AZ::Data::AssetData::AssetStatus::Ready);
@@ -81,6 +87,42 @@ namespace UnitTest
             }
         }
 
+        void CreateRecursiveHierarchy()
+        {
+            AzFramework::Spawnable::EntityList& entities = m_spawnable->GetEntities();
+            size_t numElements = entities.size();
+            AZ::EntityId parent;
+            for (size_t i=0; i<numElements; ++i)
+            {
+                AZStd::unique_ptr<AZ::Entity>& entity = entities[i];
+                auto component = entity->CreateComponent<AzFramework::TransformComponent>();
+                if (i > 0)
+                {
+                    component->SetParent(parent);
+                }
+                parent = entity->GetId();     
+            }
+        }
+
+        void CreateSingleParent()
+        {
+            AzFramework::Spawnable::EntityList& entities = m_spawnable->GetEntities();
+            size_t numElements = entities.size();
+            if (numElements > 0)
+            {
+                AZ::EntityId parent = entities[0]->GetId();
+                for (size_t i = 0; i < numElements; ++i)
+                {
+                    AZStd::unique_ptr<AZ::Entity>& entity = entities[i];
+                    auto component = entity->CreateComponent<AzFramework::TransformComponent>();
+                    if (i > 0)
+                    {
+                        component->SetParent(parent);
+                    }
+                }
+            }
+        }
+
     protected:
         AZ::Data::Asset<AzFramework::Spawnable>* m_spawnableAsset { nullptr };
         AzFramework::SpawnableEntitiesManager* m_manager { nullptr };
@@ -104,17 +146,50 @@ namespace UnitTest
             {
                 spawnedEntitiesCount += entities.size();
             };
-        m_manager->SpawnAllEntities(*m_ticket, AzFramework::SpawnablePriority_Default, {}, AZStd::move(callback));
+        AzFramework::SpawnAllEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(callback);
+        m_manager->SpawnAllEntities(*m_ticket, AZStd::move(optionalArgs));
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
 
         EXPECT_EQ(NumEntities, spawnedEntitiesCount);
     }
 
+    TEST_F(SpawnableEntitiesManagerTest, SpawnAllEntities_SetParentOnSpawnedEntities_LineageIsPreserved)
+    {
+        static constexpr size_t NumEntities = 4;
+        FillSpawnable(NumEntities);
+        CreateRecursiveHierarchy();
+
+        auto callback = [](AzFramework::EntitySpawnTicket::Id, AzFramework::SpawnableConstEntityContainerView entities)
+        {
+            AZ::EntityId parentId;
+            bool isFirst = true;
+            for (const AZ::Entity* entity : entities)
+            {
+                if (!isFirst)
+                {
+                    auto transform = entity->GetTransform();
+                    ASSERT_NE(nullptr, transform);
+                    EXPECT_EQ(parentId, transform->GetParentId());
+                }
+                else
+                {
+                    isFirst = false;
+                }
+                parentId = entity->GetId();
+            }
+        };
+        AzFramework::SpawnAllEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(callback);
+        m_manager->SpawnAllEntities(*m_ticket, AZStd::move(optionalArgs));
+        m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
+    }
+
     TEST_F(SpawnableEntitiesManagerTest, SpawnAllEntities_DeleteTicketBeforeCall_NoCrash)
     {
         {
             AzFramework::EntitySpawnTicket ticket(*m_spawnableAsset);
-            m_manager->SpawnAllEntities(ticket, AzFramework::SpawnablePriority_Default);
+            m_manager->SpawnAllEntities(ticket);
         }
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
     }
@@ -124,11 +199,175 @@ namespace UnitTest
     // SpawnEntities
     //
 
+    TEST_F(SpawnableEntitiesManagerTest, SpawnEntities_Call_AllEntitiesSpawned)
+    {
+        static constexpr size_t NumEntities = 4;
+        FillSpawnable(NumEntities);
+
+        AZStd::vector<size_t> indices = { 0, 2, 3, 1 };
+
+        size_t spawnedEntitiesCount = 0;
+        auto callback = [&spawnedEntitiesCount](AzFramework::EntitySpawnTicket::Id, AzFramework::SpawnableConstEntityContainerView entities)
+        {
+            spawnedEntitiesCount += entities.size();
+        };
+        AzFramework::SpawnEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(callback);
+        m_manager->SpawnEntities(*m_ticket, AZStd::move(indices), AZStd::move(optionalArgs));
+        m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
+
+        EXPECT_EQ(NumEntities, spawnedEntitiesCount);
+    }
+
+    TEST_F(SpawnableEntitiesManagerTest, SpawnEntities_SpawnTheSameEntity_AllEntitiesSpawned)
+    {
+        static constexpr size_t NumEntities = 1;
+        FillSpawnable(NumEntities);
+
+        AZStd::vector<size_t> indices = { 0, 0 };
+
+        size_t spawnedEntitiesCount = 0;
+        auto callback =
+            [&spawnedEntitiesCount](AzFramework::EntitySpawnTicket::Id, AzFramework::SpawnableConstEntityContainerView entities)
+        {
+            spawnedEntitiesCount += entities.size();
+        };
+        AzFramework::SpawnEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(callback);
+        m_manager->SpawnEntities(*m_ticket, AZStd::move(indices), AZStd::move(optionalArgs));
+        m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
+
+        EXPECT_EQ(NumEntities * 2, spawnedEntitiesCount);
+    }
+
+    TEST_F(SpawnableEntitiesManagerTest, SpawnEntities_MultipleSpawns_AllEntitiesSpawned)
+    {
+        static constexpr size_t NumEntities = 4;
+        FillSpawnable(NumEntities);
+
+        AZStd::vector<size_t> indices = { 0, 2, 3, 1 };
+
+        size_t spawnedEntitiesCount = 0;
+        auto callback =
+            [&spawnedEntitiesCount](AzFramework::EntitySpawnTicket::Id, AzFramework::SpawnableConstEntityContainerView entities)
+        {
+            spawnedEntitiesCount += entities.size();
+        };
+        AzFramework::SpawnEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(callback);
+        m_manager->SpawnEntities(*m_ticket, indices, optionalArgs);
+        m_manager->SpawnEntities(*m_ticket, AZStd::move(indices), AZStd::move(optionalArgs));
+        m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
+
+        EXPECT_EQ(NumEntities * 2, spawnedEntitiesCount);
+    }
+
+    TEST_F(SpawnableEntitiesManagerTest, SpawnEntities_ReferencesAreRemappedForNewBatch_AllPointToLatestParent)
+    {
+        static constexpr size_t NumEntities = 4;
+        FillSpawnable(NumEntities);
+        CreateSingleParent();
+
+        AZStd::vector<size_t> indices = { 0, 1, 2, 3 };
+        AZStd::vector<AZ::EntityId> parents;
+
+        auto callback = [&parents](AzFramework::EntitySpawnTicket::Id, AzFramework::SpawnableConstEntityContainerView entities)
+        {
+            AZ::EntityId parent = (*entities.begin())->GetId();
+            parents.push_back(parent);
+            auto it = entities.begin();
+            ++it; // Skip the first as that is the parent.
+            for (; it != entities.end(); ++it)
+            {
+                AZ::TransformInterface* transform = (*it)->GetTransform();
+                ASSERT_NE(nullptr, transform);
+                ASSERT_EQ(parent, transform->GetParentId());
+            }
+        };
+        AzFramework::SpawnEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(callback);
+        optionalArgs.m_referencePreviouslySpawnedEntities = false;
+        m_manager->SpawnEntities(*m_ticket, indices, optionalArgs);
+        m_manager->SpawnEntities(*m_ticket, AZStd::move(indices), AZStd::move(optionalArgs));
+        m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
+
+        EXPECT_NE(parents[0], parents[1]);
+    }
+
+    TEST_F(SpawnableEntitiesManagerTest, SpawnEntities_ReferencesAreRemappedForContinuedBatch_AllPointToLatestParent)
+    {
+        static constexpr size_t NumEntities = 4;
+        FillSpawnable(NumEntities);
+        CreateSingleParent();
+
+        AZStd::vector<size_t> indices = { 0, 1, 2, 3 };
+        AZStd::vector<AZ::EntityId> parents;
+
+        auto callback =
+            [&parents](AzFramework::EntitySpawnTicket::Id, AzFramework::SpawnableConstEntityContainerView entities)
+        {
+            AZ::EntityId parent = (*entities.begin())->GetId();
+            parents.push_back(parent);
+            auto it = entities.begin();
+            ++it; // Skip the first as that is the parent.
+            for (; it!=entities.end(); ++it)
+            {
+                AZ::TransformInterface* transform = (*it)->GetTransform();
+                ASSERT_NE(nullptr, transform);
+                ASSERT_EQ(parent, transform->GetParentId());
+            }
+        };
+        AzFramework::SpawnEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(callback);
+        optionalArgs.m_referencePreviouslySpawnedEntities = true;
+        m_manager->SpawnEntities(*m_ticket, indices, optionalArgs);
+        m_manager->SpawnEntities(*m_ticket, AZStd::move(indices), AZStd::move(optionalArgs));
+        m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
+
+        EXPECT_NE(parents[0], parents[1]);
+    }
+
+    TEST_F(SpawnableEntitiesManagerTest, SpawnEntities_ReferencesAreRemappedAcrossBatches_AllPointToLatestParent)
+    {
+        FillSpawnable(4);
+        CreateSingleParent();
+
+        // Spawn a regular batch but with two parents and store the id of the last entity. This will the parent for the next batch.
+        AZ::EntityId parent;
+        auto getParent = [&parent](AzFramework::EntitySpawnTicket::Id, AzFramework::SpawnableConstEntityContainerView entities)
+        {
+            ASSERT_NE(entities.begin(), entities.end());
+            parent = (*AZStd::prev(entities.end()))->GetId();
+        };
+        
+        AzFramework::SpawnEntitiesOptionalArgs optionalArgsFirstBatch;
+        optionalArgsFirstBatch.m_completionCallback = AZStd::move(getParent);
+        optionalArgsFirstBatch.m_referencePreviouslySpawnedEntities = true;
+        m_manager->SpawnEntities(*m_ticket, {0, 1, 2, 3, 0}, AZStd::move(optionalArgsFirstBatch));
+
+        // Next, spawn all the entities that have a reference to the parent that was just stored.
+        auto parentCheck = [&parent](AzFramework::EntitySpawnTicket::Id, AzFramework::SpawnableConstEntityContainerView entities)
+        {
+            for (auto& it : entities)
+            {
+                AZ::TransformInterface* transform = it->GetTransform();
+                ASSERT_NE(nullptr, transform);
+                ASSERT_EQ(parent, transform->GetParentId());
+            }
+        };
+        AzFramework::SpawnEntitiesOptionalArgs optionalArgsSecondBatch;
+        optionalArgsSecondBatch.m_completionCallback = AZStd::move(parentCheck);
+        optionalArgsSecondBatch.m_referencePreviouslySpawnedEntities = true;
+        m_manager->SpawnEntities(*m_ticket, {1, 2, 3}, AZStd::move(optionalArgsSecondBatch));
+
+        m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
+    }
+
     TEST_F(SpawnableEntitiesManagerTest, SpawnEntities_DeleteTicketBeforeCall_NoCrash)
     {
         {
             AzFramework::EntitySpawnTicket ticket(*m_spawnableAsset);
-            m_manager->SpawnEntities(ticket, AzFramework::SpawnablePriority_Default, {});
+            m_manager->SpawnEntities(ticket, {/* Deliberate empty list of indices. */});
         }
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
     }
@@ -142,7 +381,7 @@ namespace UnitTest
     {
         {
             AzFramework::EntitySpawnTicket ticket(*m_spawnableAsset);
-            m_manager->DespawnAllEntities(ticket, AzFramework::SpawnablePriority_Default);
+            m_manager->DespawnAllEntities(ticket);
         }
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
     }
@@ -156,7 +395,7 @@ namespace UnitTest
     {
         {
             AzFramework::EntitySpawnTicket ticket(*m_spawnableAsset);
-            m_manager->ReloadSpawnable(ticket, AzFramework::SpawnablePriority_Default, *m_spawnableAsset);
+            m_manager->ReloadSpawnable(ticket, *m_spawnableAsset);
         }
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
     }
@@ -183,8 +422,8 @@ namespace UnitTest
                 spawnedEntitiesCount += entities.size();
             };
 
-        m_manager->SpawnAllEntities(*m_ticket, AzFramework::SpawnablePriority_Default);
-        m_manager->ListEntities(*m_ticket, AzFramework::SpawnablePriority_Default, AZStd::move(callback));
+        m_manager->SpawnAllEntities(*m_ticket);
+        m_manager->ListEntities(*m_ticket, AZStd::move(callback));
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
 
         EXPECT_TRUE(allValidEntityIds);
@@ -197,7 +436,7 @@ namespace UnitTest
 
         {
             AzFramework::EntitySpawnTicket ticket(*m_spawnableAsset);
-            m_manager->ListEntities(ticket, AzFramework::SpawnablePriority_Default, AZStd::move(callback));
+            m_manager->ListEntities(ticket, AZStd::move(callback));
         }
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
     }
@@ -228,8 +467,8 @@ namespace UnitTest
                 }
             };
 
-        m_manager->SpawnAllEntities(*m_ticket, AzFramework::SpawnablePriority_Default);
-        m_manager->ListIndicesAndEntities(*m_ticket, AzFramework::SpawnablePriority_Default, AZStd::move(callback));
+        m_manager->SpawnAllEntities(*m_ticket);
+        m_manager->ListIndicesAndEntities(*m_ticket, AZStd::move(callback));
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
 
         EXPECT_TRUE(allValidEntityIds);
@@ -242,7 +481,7 @@ namespace UnitTest
 
         {
             AzFramework::EntitySpawnTicket ticket(*m_spawnableAsset);
-            m_manager->ListIndicesAndEntities(ticket, AzFramework::SpawnablePriority_Default, AZStd::move(callback));
+            m_manager->ListIndicesAndEntities(ticket, AZStd::move(callback));
         }
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
     }
@@ -258,7 +497,7 @@ namespace UnitTest
 
         {
             AzFramework::EntitySpawnTicket ticket(*m_spawnableAsset);
-            m_manager->ClaimEntities(ticket, AzFramework::SpawnablePriority_Default, AZStd::move(callback));
+            m_manager->ClaimEntities(ticket, AZStd::move(callback));
         }
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
     }
@@ -274,7 +513,7 @@ namespace UnitTest
 
         {
             AzFramework::EntitySpawnTicket ticket(*m_spawnableAsset);
-            m_manager->Barrier(ticket, AzFramework::SpawnablePriority_Default, AZStd::move(callback));
+            m_manager->Barrier(ticket, AZStd::move(callback));
         }
         m_manager->ProcessQueue(AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
     }
@@ -305,8 +544,16 @@ namespace UnitTest
                 defaultPriorityCallId = callCounter++;
             };
 
-        m_manager->SpawnAllEntities(*m_ticket, AzFramework::SpawnablePriority_Default, {}, AZStd::move(defaultCallback));
-        m_manager->SpawnAllEntities(highPriorityTicket, AzFramework::SpawnablePriority_High, {}, AZStd::move(highCallback));
+        AzFramework::SpawnAllEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(defaultCallback);
+        optionalArgs.m_priority = AzFramework::SpawnablePriority_Default;
+        m_manager->SpawnAllEntities(*m_ticket, AZStd::move(optionalArgs));
+
+        AzFramework::SpawnAllEntitiesOptionalArgs highPriortyOptionalArgs;
+        highPriortyOptionalArgs.m_completionCallback = AZStd::move(highCallback);
+        highPriortyOptionalArgs.m_priority = AzFramework::SpawnablePriority_High;
+        m_manager->SpawnAllEntities(highPriorityTicket, AZStd::move(highPriortyOptionalArgs));
+
         m_manager->ProcessQueue(
             AzFramework::SpawnableEntitiesManager::CommandQueuePriority::High |
             AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
@@ -333,8 +580,16 @@ namespace UnitTest
                 defaultPriorityCallId = callCounter++;
             };
 
-        m_manager->SpawnAllEntities(*m_ticket, AzFramework::SpawnablePriority_Default, {}, AZStd::move(defaultCallback));
-        m_manager->SpawnAllEntities(*m_ticket, AzFramework::SpawnablePriority_High, {}, AZStd::move(highCallback));
+        AzFramework::SpawnAllEntitiesOptionalArgs optionalArgs;
+        optionalArgs.m_completionCallback = AZStd::move(defaultCallback);
+        optionalArgs.m_priority = AzFramework::SpawnablePriority_Default;
+        m_manager->SpawnAllEntities(*m_ticket, AZStd::move(optionalArgs));
+
+        AzFramework::SpawnAllEntitiesOptionalArgs highPriortyOptionalArgs;
+        highPriortyOptionalArgs.m_completionCallback = AZStd::move(highCallback);
+        highPriortyOptionalArgs.m_priority = AzFramework::SpawnablePriority_High;
+        m_manager->SpawnAllEntities(*m_ticket, AZStd::move(highPriortyOptionalArgs));
+
         m_manager->ProcessQueue(
             AzFramework::SpawnableEntitiesManager::CommandQueuePriority::High |
             AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);