[LYN-3099] Fixed some issues with vegetation planting on surfaces (#1554)

* [LYN-3099] Fix vegetation raycasts to use bounded ray queries instead of FLT_MAX.
Raycasts with a distance of FLT_MAX sometimes overflowed deep in IntersectSegmentTriangleCCW, so it's better to have strict start/end positional queries.  We have specific starts and ends anyways, so it's a safer approach anyways.
This also adds support for Non-Uniform Scale for meshes, since it was clearly not working correctly in vegetation when testing various scaled meshes.

* Addressed PR feedback

Gems/Vegetation/Code/Source/Components/MeshBlockerComponent.cpp

@@ -129,9 +129,16 @@ namespace Vegetation
         }
     }
 
+    MeshBlockerComponent::MeshBlockerComponent()
+        : AreaComponentBase()
+        , m_nonUniformScaleChangedHandler([this]([[maybe_unused]] const AZ::Vector3& scale) { this->OnCompositionChanged(); })
+    {
+    }
+
     MeshBlockerComponent::MeshBlockerComponent(const MeshBlockerConfig& configuration)
         : AreaComponentBase(configuration)
         , m_configuration(configuration)
+        , m_nonUniformScaleChangedHandler([this]([[maybe_unused]] const AZ::Vector3& scale) { this->OnCompositionChanged(); })
     {
     }
 
@@ -139,6 +146,9 @@ namespace Vegetation
     {
         AZ::Render::MeshComponentNotificationBus::Handler::BusConnect(GetEntityId());
 
+        AZ::NonUniformScaleRequestBus::Event(
+            GetEntityId(), &AZ::NonUniformScaleRequests::RegisterScaleChangedEvent, m_nonUniformScaleChangedHandler);
+
         UpdateMeshData();
         m_refresh = false;
 
@@ -153,6 +163,7 @@ namespace Vegetation
     {
         AreaComponentBase::Deactivate(); //must deactivate base first to ensure AreaRequestBus disconnect waits for other threads
 
+        m_nonUniformScaleChangedHandler.Disconnect();
         SurfaceData::SurfaceDataSystemNotificationBus::Handler::BusDisconnect();
 
         m_refresh = false;
@@ -260,9 +271,10 @@ namespace Vegetation
 
         AZ::Vector3 outPosition;
         AZ::Vector3 outNormal;
-        const AZ::Vector3 rayOrigin(point.m_position.GetX(), point.m_position.GetY(), m_meshBoundsForIntersection.GetMax().GetZ());
-        const AZ::Vector3 rayDirection = -AZ::Vector3::CreateAxisZ();
-        bool intersected = SurfaceData::GetMeshRayIntersection(*mesh, m_meshWorldTM, m_meshWorldTMInverse, rayOrigin, rayDirection, outPosition, outNormal) &&
+        const AZ::Vector3 rayStart(point.m_position.GetX(), point.m_position.GetY(), m_meshBoundsForIntersection.GetMax().GetZ());
+        const AZ::Vector3 rayEnd(point.m_position.GetX(), point.m_position.GetY(), m_meshBoundsForIntersection.GetMin().GetZ());
+        bool intersected = SurfaceData::GetMeshRayIntersection(
+            *mesh, m_meshWorldTM, m_meshWorldTMInverse, m_meshNonUniformScale, rayStart, rayEnd, outPosition, outNormal) &&
             m_meshBoundsForIntersection.Contains(outPosition);
         m_cachedRayHits[point.m_handle] = intersected;
         return intersected;
@@ -377,10 +389,10 @@ namespace Vegetation
                 m_meshBoundsForIntersection.GetMin().GetZ() + m_meshBoundsForIntersection.GetExtents().GetZ() * m_configuration.m_meshHeightPercentMax);
 
             AZ::Vector3 cornerMin = m_meshBoundsForIntersection.GetMin();
-            cornerMin.SetZ(heights.first);
+            cornerMin.SetZ(heights.first - s_rayAABBHeightPadding);
 
             AZ::Vector3 cornerMax = m_meshBoundsForIntersection.GetMax();
-            cornerMax.SetZ(heights.second);
+            cornerMax.SetZ(heights.second + s_rayAABBHeightPadding);
 
             m_meshBoundsForIntersection.Set(cornerMin, cornerMax);
         }
@@ -392,6 +404,9 @@ namespace Vegetation
         AZ::TransformBus::EventResult(m_meshWorldTM, GetEntityId(), &AZ::TransformBus::Events::GetWorldTM);
         m_meshWorldTMInverse = m_meshWorldTM.GetInverse();
 
+        m_meshNonUniformScale = AZ::Vector3::CreateOne();
+        AZ::NonUniformScaleRequestBus::EventResult(m_meshNonUniformScale, GetEntityId(), &AZ::NonUniformScaleRequests::GetScale);
+
         AreaComponentBase::OnCompositionChanged();
     }
 

Gems/Vegetation/Code/Source/Components/MeshBlockerComponent.h

@@ -9,6 +9,7 @@
 
 #include <AzCore/Asset/AssetCommon.h>
 #include <AzCore/Component/Component.h>
+#include <AzCore/Component/NonUniformScaleBus.h>
 #include <AzCore/Component/TickBus.h>
 #include <Vegetation/Ebuses/AreaRequestBus.h>
 #include <Vegetation/Ebuses/MeshBlockerRequestBus.h>
@@ -62,7 +63,7 @@ namespace Vegetation
         static void Reflect(AZ::ReflectContext* context);
 
         MeshBlockerComponent(const MeshBlockerConfig& configuration);
-        MeshBlockerComponent() = default;
+        MeshBlockerComponent();
         ~MeshBlockerComponent() = default;
 
         //////////////////////////////////////////////////////////////////////////
@@ -122,6 +123,8 @@ namespace Vegetation
         MeshBlockerConfig m_configuration;
         AZStd::atomic_bool m_refresh{ false };
 
+        AZ::NonUniformScaleChangedEvent::Handler m_nonUniformScaleChangedHandler; ///< Responds to changes in non-uniform scale.
+
         // cached data
         mutable AZStd::recursive_mutex m_cacheMutex;
         AZ::Data::Asset<AZ::Data::AssetData> m_meshAssetData;
@@ -129,9 +132,12 @@ namespace Vegetation
         AZ::Transform m_meshWorldTMInverse = AZ::Transform::CreateIdentity();
         AZ::Aabb m_meshBounds = AZ::Aabb::CreateNull();
         AZ::Aabb m_meshBoundsForIntersection = AZ::Aabb::CreateNull();
+        AZ::Vector3 m_meshNonUniformScale = AZ::Vector3::CreateOne();
         bool m_meshVisible = false;
 
         using CachedRayHits = AZStd::unordered_map<ClaimHandle, bool>;
         CachedRayHits m_cachedRayHits;
+
+        static constexpr float s_rayAABBHeightPadding = 0.1f;
     };
 }