Cleaning up NetworkTime and reworking how we approach network interpolation

Signed-off-by: puvvadar <puvvadar@amazon.com>

Gems/Multiplayer/Code/Include/Multiplayer/Components/NetBindComponent.h

@@ -35,7 +35,7 @@ namespace Multiplayer
     using EntityMigrationStartEvent = AZ::Event<ClientInputId>;
     using EntityMigrationEndEvent = AZ::Event<>;
     using EntityServerMigrationEvent = AZ::Event<const ConstNetworkEntityHandle&, HostId, AzNetworking::ConnectionId>;
-    using EntityPreRenderEvent = AZ::Event<float, float>;
+    using EntityPreRenderEvent = AZ::Event<float>;
     using EntityCorrectionEvent = AZ::Event<>;
 
     //! @class NetBindComponent
@@ -118,7 +118,7 @@ namespace Multiplayer
         void NotifyMigrationStart(ClientInputId migratedInputId);
         void NotifyMigrationEnd();
         void NotifyServerMigration(HostId hostId, AzNetworking::ConnectionId connectionId);
-        void NotifyPreRender(float deltaTime, float blendFactor);
+        void NotifyPreRender(float deltaTime);
         void NotifyCorrection();
 
         void AddEntityStopEventHandler(EntityStopEvent::Handler& eventHandler);

Gems/Multiplayer/Code/Include/Multiplayer/Components/NetworkTransformComponent.h

@@ -29,24 +29,9 @@ namespace Multiplayer
         void OnDeactivate(Multiplayer::EntityIsMigrating entityIsMigrating) override;
 
     private:
-        void OnPreRender(float deltaTime, float blendFactor);
+        void OnPreRender(float deltaTime);
         void OnCorrection();
 
-        void OnRotationChangedEvent(const AZ::Quaternion& rotation);
-        void OnTranslationChangedEvent(const AZ::Vector3& translation);
-        void OnScaleChangedEvent(float scale);
-        void OnResetCountChangedEvent();
-
-        void UpdateTargetHostFrameId();
-
-        AZ::Transform m_previousTransform = AZ::Transform::CreateIdentity();
-        AZ::Transform m_targetTransform = AZ::Transform::CreateIdentity();
-
-        AZ::Event<AZ::Quaternion>::Handler m_rotationEventHandler;
-        AZ::Event<AZ::Vector3>::Handler m_translationEventHandler;
-        AZ::Event<float>::Handler m_scaleEventHandler;
-        AZ::Event<uint8_t>::Handler m_resetCountEventHandler;
-
         EntityPreRenderEvent::Handler m_entityPreRenderEventHandler;
         EntityCorrectionEvent::Handler m_entityCorrectionEventHandler;
 

Gems/Multiplayer/Code/Source/AutoGen/AutoComponent_Header.jinja

@@ -7,21 +7,21 @@
 {% macro DeclareNetworkPropertyGetter(Property) %}
 {% set PropertyName = UpperFirst(Property.attrib['Name']) %}
 {%     if Property.attrib['Container'] == 'Array' %}
-{% if Property.attrib['IsRewindable']|booleanTrue %}
+{%          if Property.attrib['IsRewindable']|booleanTrue %}
 const RewindableArray<{{ Property.attrib['Type'] }}, {{ Property.attrib['Count'] }}>& Get{{ PropertyName }}Array() const;
-{% else %}
+{%          else %}
 const AZStd::array<{{ Property.attrib['Type'] }}, {{ Property.attrib['Count'] }}>& Get{{ PropertyName }}Array() const;
-{% endif %}
+{%          endif %}
 const {{ Property.attrib['Type'] }}& Get{{ PropertyName }}(int32_t index) const;
 {%          if Property.attrib['GenerateEventBindings']|booleanTrue %}
 void {{ PropertyName }}AddEvent(AZ::Event<int32_t, {{ Property.attrib['Type'] }}>::Handler& handler);
 {%          endif %}
 {%     elif Property.attrib['Container'] == 'Vector' %}
-{% if Property.attrib['IsRewindable']|booleanTrue %}
+{%          if Property.attrib['IsRewindable']|booleanTrue %}
 const RewindableFixedVector<{{ Property.attrib['Type'] }}, {{ Property.attrib['Count'] }}>& Get{{ PropertyName }}Vector() const;
-{% else %}
+{%          else %}
 const AZStd::fixed_vector<{{ Property.attrib['Type'] }}, {{ Property.attrib['Count'] }}>& Get{{ PropertyName }}Vector() const;
-{% endif %}
+{%          endif %}
 const {{ Property.attrib['Type'] }}& Get{{ PropertyName }}(int32_t index) const;
 const {{ Property.attrib['Type'] }}& {{ PropertyName }}GetBack() const;
 uint32_t {{ PropertyName }}GetSize() const;
@@ -31,6 +31,9 @@ void {{ PropertyName }}SizeChangedAddEvent(AZ::Event<uint32_t>::Handler& handler
 {%          endif %}
 {%     else %}
 const {{ Property.attrib['Type'] }}& Get{{ PropertyName }}() const;
+{%          if Property.attrib['IsRewindable']|booleanTrue %}
+const {{ Property.attrib['Type'] }}& Get{{ PropertyName }}Previous() const;
+{%          endif %}
 {%          if Property.attrib['GenerateEventBindings']|booleanTrue %}
 void {{ PropertyName }}AddEvent(AZ::Event<{{ Property.attrib['Type'] }}>::Handler& handler);
 {%          endif %}

Gems/Multiplayer/Code/Source/AutoGen/AutoComponent_Source.jinja

@@ -3,11 +3,11 @@
 {% macro LowerFirst(text) %}{{ text[0] | lower}}{{ text[1:] }}{% endmacro %}
 {% macro DefineNetworkPropertyGet(ClassName, Property, Prefix = '') %}
 {%     if Property.attrib['Container'] == 'Array' %}
-{% if Property.attrib['IsRewindable']|booleanTrue %}
+{%          if Property.attrib['IsRewindable']|booleanTrue %}
 const RewindableArray<{{ Property.attrib['Type'] }}, {{ Property.attrib['Count'] }}>& {{ ClassName }}::Get{{ UpperFirst(Property.attrib['Name']) }}Array() const
-{% else %}
+{%          else %}
 const AZStd::array<{{ Property.attrib['Type'] }}, {{ Property.attrib['Count'] }}>& {{ ClassName }}::Get{{ UpperFirst(Property.attrib['Name']) }}Array() const
-{% endif %}
+{%          endif %}
 {
     return {{ Prefix }}m_{{ LowerFirst(Property.attrib['Name']) }};
 }
@@ -25,11 +25,11 @@ void {{ ClassName }}::{{ UpperFirst(Property.attrib['Name']) }}AddEvent(AZ::Even
 
 {%          endif %}
 {%     elif Property.attrib['Container'] == 'Vector' %}
-{% if Property.attrib['IsRewindable']|booleanTrue %}
+{%          if Property.attrib['IsRewindable']|booleanTrue %}
 const RewindableFixedVector<{{ Property.attrib['Type'] }}, {{ Property.attrib['Count'] }}>& {{ ClassName }}::Get{{ UpperFirst(Property.attrib['Name']) }}Vector() const
-{% else %}
+{%          else %}
 const AZStd::fixed_vector<{{ Property.attrib['Type'] }}, {{ Property.attrib['Count'] }}>& {{ ClassName }}::Get{{ UpperFirst(Property.attrib['Name']) }}Vector() const
-{% endif %}
+{%          endif %}
 {
     return {{ Prefix }}m_{{ LowerFirst(Property.attrib['Name']) }};
 }
@@ -68,7 +68,12 @@ const {{ Property.attrib['Type'] }}& {{ ClassName }}::Get{{ UpperFirst(Property.
 {
     return {{ Prefix }}m_{{ LowerFirst(Property.attrib['Name']) }};
 }
-
+{%          if Property.attrib['IsRewindable']|booleanTrue %}
+const {{ Property.attrib['Type'] }}& {{ ClassName }}::Get{{ UpperFirst(Property.attrib['Name']) }}Previous() const
+{
+    return {{ Prefix }}m_{{ LowerFirst(Property.attrib['Name']) }}.GetPrevious();
+}
+{%          endif %}
 {%          if Property.attrib['GenerateEventBindings']|booleanTrue %}
 void {{ ClassName }}::{{ UpperFirst(Property.attrib['Name']) }}AddEvent(AZ::Event<{{ Property.attrib['Type'] }}>::Handler& handler)
 {

Gems/Multiplayer/Code/Source/AutoGen/NetworkTransformComponent.AutoComponent.xml

@@ -12,9 +12,9 @@
 
     <Include File="Multiplayer/MultiplayerTypes.h"/>
 
-    <NetworkProperty Type="AZ::Quaternion" Name="rotation" Init="AZ::Quaternion::CreateIdentity()" ReplicateFrom="Authority" ReplicateTo="Client" IsRewindable="true" IsPredictable="true" IsPublic="true" Container="Object" ExposeToEditor="false" ExposeToScript="false" GenerateEventBindings="true" />
+    <NetworkProperty Type="AZ::Quaternion" Name="rotation" Init="AZ::Quaternion::CreateIdentity()" ReplicateFrom="Authority" ReplicateTo="Client" IsRewindable="true" IsPredictable="true" IsPublic="true" Container="Object" ExposeToEditor="false" ExposeToScript="false" GenerateEventBindings="false" />
     <NetworkProperty Type="AZ::Vector3" Name="translation" Init="AZ::Vector3::CreateZero()" ReplicateFrom="Authority" ReplicateTo="Client" IsRewindable="true" IsPredictable="true" IsPublic="true" Container="Object" ExposeToEditor="false" ExposeToScript="false" GenerateEventBindings="true" />
-    <NetworkProperty Type="float" Name="scale" Init="1.0f" ReplicateFrom="Authority" ReplicateTo="Client" IsRewindable="true" IsPredictable="true" IsPublic="true" Container="Object" ExposeToEditor="false" ExposeToScript="false" GenerateEventBindings="true" />
+    <NetworkProperty Type="float" Name="scale" Init="1.0f" ReplicateFrom="Authority" ReplicateTo="Client" IsRewindable="true" IsPredictable="true" IsPublic="true" Container="Object" ExposeToEditor="false" ExposeToScript="false" GenerateEventBindings="false" />
     <NetworkProperty Type="uint8_t"     Name="resetCount" Init="0" ReplicateFrom="Authority" ReplicateTo="Client" IsRewindable="false" IsPredictable="true" IsPublic="true" Container="Object" ExposeToEditor="false" ExposeToScript="false" GenerateEventBindings="true" />
     <NetworkProperty Type="NetEntityId" Name="parentEntityId" Init="InvalidNetEntityId" ReplicateFrom="Authority" ReplicateTo="Client" IsRewindable="true" IsPredictable="true" IsPublic="true" Container="Object" ExposeToEditor="false" ExposeToScript="false" GenerateEventBindings="true" />
     <NetworkProperty Type="int32_t"     Name="parentAttachmentBoneId" Init="-1" ReplicateFrom="Authority" ReplicateTo="Client" IsRewindable="true" IsPredictable="true" IsPublic="true" Container="Object" ExposeToEditor="false" ExposeToScript="false" GenerateEventBindings="true" />

Gems/Multiplayer/Code/Source/Components/NetBindComponent.cpp

@@ -403,9 +403,9 @@ namespace Multiplayer
         m_entityServerMigrationEvent.Signal(m_netEntityHandle, hostId, connectionId);
     }
 
-    void NetBindComponent::NotifyPreRender(float deltaTime, float blendFactor)
+    void NetBindComponent::NotifyPreRender(float deltaTime)
     {
-        m_entityPreRenderEvent.Signal(deltaTime, blendFactor);
+        m_entityPreRenderEvent.Signal(deltaTime);
     }
 
     void NetBindComponent::NotifyCorrection()

Gems/Multiplayer/Code/Source/Components/NetworkTransformComponent.cpp

@@ -26,11 +26,7 @@ namespace Multiplayer
     }
 
     NetworkTransformComponent::NetworkTransformComponent()
-        : m_rotationEventHandler([this](const AZ::Quaternion& rotation) { OnRotationChangedEvent(rotation); })
-        , m_translationEventHandler([this](const AZ::Vector3& translation) { OnTranslationChangedEvent(translation); })
-        , m_scaleEventHandler([this](float scale) { OnScaleChangedEvent(scale); })
-        , m_resetCountEventHandler([this](const uint8_t&) { OnResetCountChangedEvent(); })
-        , m_entityPreRenderEventHandler([this](float deltaTime, float blendFactor) { OnPreRender(deltaTime, blendFactor); })
+        : m_entityPreRenderEventHandler([this](float deltaTime) { OnPreRender(deltaTime); })
         , m_entityCorrectionEventHandler([this]() { OnCorrection(); })
     {
         ;
@@ -43,15 +39,8 @@ namespace Multiplayer
 
     void NetworkTransformComponent::OnActivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
     {
-        RotationAddEvent(m_rotationEventHandler);
-        TranslationAddEvent(m_translationEventHandler);
-        ScaleAddEvent(m_scaleEventHandler);
-        ResetCountAddEvent(m_resetCountEventHandler);
         GetNetBindComponent()->AddEntityPreRenderEventHandler(m_entityPreRenderEventHandler);
         GetNetBindComponent()->AddEntityCorrectionEventHandler(m_entityCorrectionEventHandler);
-
-        // When coming into relevance, reset all blending factors so we don't interpolate to our start position
-        OnResetCountChangedEvent();
     }
 
     void NetworkTransformComponent::OnDeactivate([[maybe_unused]] Multiplayer::EntityIsMigrating entityIsMigrating)
@@ -59,59 +48,31 @@ namespace Multiplayer
         ;
     }
 
-    void NetworkTransformComponent::OnRotationChangedEvent(const AZ::Quaternion& rotation)
-    {
-        m_previousTransform.SetRotation(m_targetTransform.GetRotation());
-        m_targetTransform.SetRotation(rotation);
-        UpdateTargetHostFrameId();
-    }
-
-    void NetworkTransformComponent::OnTranslationChangedEvent(const AZ::Vector3& translation)
-    {
-        m_previousTransform.SetTranslation(m_targetTransform.GetTranslation());
-        m_targetTransform.SetTranslation(translation);
-        UpdateTargetHostFrameId();
-    }
-
-    void NetworkTransformComponent::OnScaleChangedEvent(float scale)
-    {
-        m_previousTransform.SetUniformScale(m_targetTransform.GetUniformScale());
-        m_targetTransform.SetUniformScale(scale);
-        UpdateTargetHostFrameId();
-    }
-
-    void NetworkTransformComponent::OnResetCountChangedEvent()
-    {
-        m_targetTransform.SetRotation(GetRotation());
-        m_targetTransform.SetTranslation(GetTranslation());
-        m_targetTransform.SetUniformScale(GetScale());
-        m_previousTransform = m_targetTransform;
-    }
-
-    void NetworkTransformComponent::UpdateTargetHostFrameId()
-    {
-        HostFrameId currentHostFrameId = Multiplayer::GetNetworkTime()->GetHostFrameId();
-        if (currentHostFrameId > m_targetHostFrameId)
-        {
-            m_targetHostFrameId = currentHostFrameId;
-        }
-    }
-
-    void NetworkTransformComponent::OnPreRender([[maybe_unused]] float deltaTime, float blendFactor)
+    void NetworkTransformComponent::OnPreRender([[maybe_unused]] float deltaTime)
     {
         if (!HasController())
         {
             AZ::Transform blendTransform;
-            if (Multiplayer::GetNetworkTime() && Multiplayer::GetNetworkTime()->GetHostFrameId() > m_targetHostFrameId)
+            blendTransform.SetRotation(GetRotation());
+            blendTransform.SetTranslation(GetTranslation());
+            blendTransform.SetUniformScale(GetScale());
+
+            const float blendFactor = GetNetworkTime()->GetHostBlendFactor();
+            if (!!AZ::IsClose(blendFactor, 1.0f))
             {
-                m_previousTransform = m_targetTransform;
-                blendTransform = m_targetTransform;
-            }
-            else
-            {
-                blendTransform.SetRotation(m_previousTransform.GetRotation().Slerp(m_targetTransform.GetRotation(), blendFactor));
-                blendTransform.SetTranslation(m_previousTransform.GetTranslation().Lerp(m_targetTransform.GetTranslation(), blendFactor));
-                blendTransform.SetUniformScale(AZ::Lerp(m_previousTransform.GetUniformScale(), m_targetTransform.GetUniformScale(), blendFactor));
+                AZ::Transform blendTransformPrevious;
+                blendTransformPrevious.SetRotation(GetRotationPrevious());
+                blendTransformPrevious.SetTranslation(GetTranslationPrevious());
+                blendTransformPrevious.SetUniformScale(GetScalePrevious());
+
+                if (!blendTransform.IsClose(blendTransformPrevious))
+                {
+                    blendTransform.SetRotation(blendTransformPrevious.GetRotation().Slerp(blendTransform.GetRotation(), blendFactor));
+                    blendTransform.SetTranslation(
+                        blendTransformPrevious.GetTranslation().Lerp(blendTransform.GetTranslation(), blendFactor));
+                    blendTransform.SetUniformScale(
+                        AZ::Lerp(blendTransformPrevious.GetUniformScale(), blendTransform.GetUniformScale(), blendFactor));
+                }
             }
 
             if (!GetTransformComponent()->GetWorldTM().IsClose(blendTransform))
@@ -124,12 +85,15 @@ namespace Multiplayer
     void NetworkTransformComponent::OnCorrection()
     {
         // Snap to latest
-        OnResetCountChangedEvent();
+        AZ::Transform targetTransform;
+        targetTransform.SetRotation(GetRotation());
+        targetTransform.SetTranslation(GetTranslation());
+        targetTransform.SetUniformScale(GetScale());
 
         // Hard set the entities transform
-        if (!GetTransformComponent()->GetWorldTM().IsClose(m_targetTransform))
+        if (!GetTransformComponent()->GetWorldTM().IsClose(targetTransform))
         {
-            GetTransformComponent()->SetWorldTM(m_targetTransform);
+            GetTransformComponent()->SetWorldTM(targetTransform);
         }
     }
 

Gems/Multiplayer/Code/Source/MultiplayerSystemComponent.cpp

@@ -922,7 +922,7 @@ namespace Multiplayer
 
             for (NetBindComponent* netBindComponent : gatheredEntities)
             {
-                netBindComponent->NotifyPreRender(deltaTime, m_renderBlendFactor);
+                netBindComponent->NotifyPreRender(deltaTime);
             }
         }
         else
@@ -934,7 +934,7 @@ namespace Multiplayer
                 NetBindComponent* netBindComponent = entity->FindComponent<NetBindComponent>();
                 if (netBindComponent != nullptr)
                 {
-                    netBindComponent->NotifyPreRender(deltaTime, m_renderBlendFactor);
+                    netBindComponent->NotifyPreRender(deltaTime);
                 }
             }
         }

Gems/Multiplayer/Code/Source/NetworkTime/NetworkTime.cpp

@@ -110,8 +110,15 @@ namespace Multiplayer
 
                     if (networkTransform != nullptr)
                     {
-                        // We're not presently factoring in interpolated position here
-                        const AZ::Vector3 rewindCenter = networkTransform->GetTranslation(); // Get the rewound position
+                        // Get the rewound position for target host frame ID plus the one preceding it for potential lerp
+                        AZ::Vector3 rewindCenter = networkTransform->GetTranslation();
+                        const AZ::Vector3 rewindCenterPrevious = networkTransform->GetTranslationPrevious();
+                        const float blendFactor = GetNetworkTime()->GetHostBlendFactor();
+                        if (!AZ::IsClose(blendFactor, 1.0f) && !rewindCenter.IsClose(rewindCenterPrevious))
+                        {
+                            // If we have a blend factor, lerp the translation for accuracy
+                            rewindCenter = rewindCenterPrevious.Lerp(rewindCenter, blendFactor);
+                        }
                         const AZ::Vector3 rewindOffset = rewindCenter - currentCenter; // Compute offset between rewound and current positions
                         const AZ::Aabb rewoundAabb = currentBounds.GetTranslated(rewindOffset); // Apply offset to the entity aabb