Level Coloration:

- FPrimitiveSceneProxy derived classes no longer need to implement custom logic to set their level color, as it is now fetched directly from the FPrimitiveSceneProxyDesc owner's level and pushed into the corresponding FPrimitiveSceneProxy when creating the proxies.
  - World Partition level streaming objects will push a deterministic random color based on the obejct's name in the level streaming objects.
  - Added Nanite support for level coloration debug view mode.

This will then serves as a base for existing and future coloring debug view modes, instead of doing custom debug views.

#rb Sebastien.Lussier

[CL 29951102 by jeanfrancois dube in ue5-main branch]

Engine/Plugins/Experimental/ImagePlate/Source/ImagePlate/Private/ImagePlateComponent.cpp

@@ -10,8 +10,6 @@
 #include "RayTracingInstance.h"
 #include "SceneManagement.h"
 #include "Engine/Engine.h"
-#include "Engine/LevelStreaming.h"
-#include "LevelUtils.h"
 #include "Materials/MaterialInstanceDynamic.h"
 #include "DynamicMeshBuilder.h"
 #include "Components/SceneCaptureComponent2D.h"
@@ -67,19 +65,6 @@ namespace
 			: FPrimitiveSceneProxy(InComponent)
 			, VertexFactory(GetScene().GetFeatureLevel(), "FImagePlateSceneProxy")
 		{
-			AActor* Owner = InComponent->GetOwner();
-			if (Owner)
-			{
-				// Level colorization
-				ULevel* Level = Owner->GetLevel();
-				ULevelStreaming* LevelStreaming = FLevelUtils::FindStreamingLevel( Level );
-				if ( LevelStreaming )
-				{
-					// Selection takes priority over level coloration.
-					SetLevelColor(LevelStreaming->LevelColor);
-				}
-			}
-
 			Material = InComponent->GetPlate().DynamicMaterial ? InComponent->GetPlate().DynamicMaterial : InComponent->GetPlate().Material;
 			if (Material)
 			{

Engine/Shaders/Private/Nanite/NaniteDebugViews.usf

@@ -33,6 +33,7 @@ float3 SelectionColor;
 #define DEBUG_VIEW_WIREFRAME 1
 #define DEBUG_VIEW_SHADER_COMPLEXITY 2
 #define DEBUG_VIEW_LIGHTMAP_DENSITY 3
+#define DEBUG_VIEW_LEVEL_COLOR 4
 uint DebugViewMode;
 
 #define SOBEL_WIREFRAME_FILTER_ONLY 0
@@ -282,6 +283,12 @@ void ExportDebugViewPS(
 				// Alpha channel needs to be 1 to have decals working where the framebuffer blend is setup to multiply with alpha
 				OutColor = float4(FinalComplexity.xyz, 1.0f);
 			}
+			else if (DebugViewMode == DEBUG_VIEW_LEVEL_COLOR)
+			{
+				const bool bIsSelected = IsInstanceSelected(InstanceData, VisibleCluster, TriIndex);
+				const float3 SolidColor = CondMask(bIsSelected, SelectionColor, PrimitiveData.LevelColor);
+				OutColor = float4(SolidColor, 1.0f);
+			}
 		#endif
 			else
 			{

Engine/Source/Runtime/Engine/Private/Components/BillboardComponent.cpp

@@ -11,8 +11,6 @@
 #include "SceneManagement.h"
 #include "Engine/Light.h"
 #include "Engine/Engine.h"
-#include "Engine/LevelStreaming.h"
-#include "LevelUtils.h"
 #include "TextureResource.h"
 
 #include UE_INLINE_GENERATED_CPP_BY_NAME(BillboardComponent)
@@ -103,14 +101,6 @@ public:
 #else // WITH_EDITORONLY_DATA
 			bIsActorLocked = false;
 #endif // WITH_EDITORONLY_DATA
-
-			// Level colorization
-			ULevel* Level = Owner->GetLevel();
-			if (ULevelStreaming* LevelStreaming = FLevelUtils::FindStreamingLevel(Level))
-			{
-				// Selection takes priority over level coloration.
-				SetLevelColor(LevelStreaming->LevelColor);
-			}
 		}
 
 		FColor NewPropertyColor;

Engine/Source/Runtime/Engine/Private/Components/MaterialBillboardComponent.cpp

@@ -9,8 +9,6 @@
 #include "SceneInterface.h"
 #include "SceneManagement.h"
 #include "Engine/Engine.h"
-#include "Engine/LevelStreaming.h"
-#include "LevelUtils.h"
 #include "PrimitiveSceneProxy.h"
 #include "StaticMeshResources.h"
 #include "PSOPrecache.h"
@@ -64,19 +62,6 @@ public:
 	, BaseColor(FColor::White)
 	, VertexFactory(GetScene().GetFeatureLevel(), "FMaterialSpriteSceneProxy")
 	{
-		AActor* Owner = InComponent->GetOwner();
-		if (Owner)
-		{
-			// Level colorization
-			ULevel* Level = Owner->GetLevel();
-			ULevelStreaming* LevelStreaming = FLevelUtils::FindStreamingLevel( Level );
-			if ( LevelStreaming )
-			{
-				// Selection takes priority over level coloration.
-				SetLevelColor(LevelStreaming->LevelColor);
-			}
-		}
-
 		for (int32 ElementIndex = 0; ElementIndex < Elements.Num(); ElementIndex++)
 		{
 			UMaterialInterface* Material = Elements[ElementIndex].Material;

Engine/Source/Runtime/Engine/Private/ModelRender.cpp

@@ -17,8 +17,6 @@
 #include "Materials/Material.h"
 #include "Materials/MaterialRenderProxy.h"
 #include "Engine/Engine.h"
-#include "Engine/LevelStreaming.h"
-#include "LevelUtils.h"
 #include "HModel.h"
 #include "Components/ModelComponent.h"
 #include "Engine/Brush.h"
@@ -264,18 +262,6 @@ public:
 
 		bGoodCandidateForCachedShadowmap = CacheShadowDepthsFromPrimitivesUsingWPO() || (!MaterialRelevance.bUsesWorldPositionOffset && !MaterialRelevance.bUsesDisplacement);
 
-		// Try to find a color for level coloration.
-		UObject* ModelOuter = InComponent->GetModel()->GetOuter();
-		ULevel* Level = Cast<ULevel>( ModelOuter );
-		if ( Level )
-		{
-			ULevelStreaming* LevelStreaming = FLevelUtils::FindStreamingLevel( Level );
-			if ( LevelStreaming )
-			{
-				SetLevelColor(LevelStreaming->LevelColor);
-			}
-		}
-
 		// Get a color for property coloration.
 		FColor NewPropertyColor;
 		GEngine->GetPropertyColorationColor( (UObject*)InComponent, NewPropertyColor );

Engine/Source/Runtime/Engine/Private/Particles/ParticleSystemRender.cpp

@@ -6533,7 +6533,6 @@ FParticleSystemSceneProxy::FParticleSystemSceneProxy(UParticleSystemComponent* C
 	, FirstFreeMeshBatch(0)
 {
 	SetWireframeColor(FLinearColor(3.0f, 0.0f, 0.0f));
-	SetLevelColor(FLinearColor(1.0f, 1.0f, 0.0f));
 	SetPropertyColor(FLinearColor(1.0f, 1.0f, 1.0f));
 
 	LODMethod = Component->LODMethod;

Engine/Source/Runtime/Engine/Private/PrimitiveSceneProxy.cpp

@@ -8,7 +8,9 @@
 #include "PrimitiveSceneProxyDesc.h"
 #include "PrimitiveViewRelevance.h"
 #include "UObject/Package.h"
+#include "LevelUtils.h"
 #include "Engine/Engine.h"
+#include "Engine/LevelStreaming.h"
 #include "EngineUtils.h"
 #include "Components/BrushComponent.h"
 #include "PrimitiveSceneInfo.h"
@@ -413,7 +415,6 @@ FPrimitiveSceneProxy::FPrimitiveSceneProxy(const UPrimitiveComponent* InComponen
 FPrimitiveSceneProxy::FPrimitiveSceneProxy(const FPrimitiveSceneProxyDesc& InProxyDesc, FName InResourceName) :
 #if !(UE_BUILD_SHIPPING || UE_BUILD_TEST)
 	WireframeColor(FLinearColor::White)
-,	LevelColor(FLinearColor::White)
 ,	PropertyColor(FLinearColor::White)
 ,	
 #endif
@@ -551,6 +552,13 @@ FPrimitiveSceneProxy::FPrimitiveSceneProxy(const FPrimitiveSceneProxyDesc& InPro
 		{
 			SetForceHidden(!Level->bIsVisible);
 		}
+
+#if !(UE_BUILD_SHIPPING || UE_BUILD_TEST)
+		if (ULevelStreaming* LevelStreaming = FLevelUtils::FindStreamingLevel(Level))
+		{
+			SetLevelColor(LevelStreaming->LevelColor);
+		}
+#endif
 	}
 
 #if STATS

Engine/Source/Runtime/Engine/Private/Rendering/NaniteResources.cpp

@@ -717,7 +717,6 @@ FSceneProxy::FSceneProxy(const FMaterialAudit& MaterialAudit, const FStaticMeshS
 
 	InstanceWPODisableDistance = ProxyDesc.WorldPositionOffsetDisableDistance;
 
-	SetLevelColor(FLinearColor::White);
 	SetPropertyColor(FLinearColor::White);
 	SetWireframeColor(ProxyDesc.GetWireframeColor());
 

Engine/Source/Runtime/Engine/Private/SkeletalMesh.cpp

@@ -5608,9 +5608,6 @@ void USkeletalMeshSocket::Serialize(FArchive& Ar)
 /*-----------------------------------------------------------------------------
 FSkeletalMeshSceneProxy
 -----------------------------------------------------------------------------*/
-#include "Engine/LevelStreaming.h"
-#include "LevelUtils.h"
-
 #include UE_INLINE_GENERATED_CPP_BY_NAME(SkeletalMesh)
 
 const FQuat SphylBasis(FVector(1.0f / FMath::Sqrt(2.0f), 0.0f, 1.0f / FMath::Sqrt(2.0f)), UE_PI);
@@ -5768,17 +5765,6 @@ FSkeletalMeshSceneProxy::FSkeletalMeshSceneProxy(const USkinnedMeshComponent* Co
 
 	bCastDynamicShadow = bCastDynamicShadow && bAnySectionCastsShadow;
 
-	// Try to find a color for level coloration.
-	if( Owner )
-	{
-		ULevel* Level = Owner->GetLevel();
-		ULevelStreaming* LevelStreaming = FLevelUtils::FindStreamingLevel( Level );
-		if ( LevelStreaming )
-		{
-			SetLevelColor(LevelStreaming->LevelColor);
-		}
-	}
-
 	// Get a color for property coloration
 	FColor NewPropertyColor;
 	if (GEngine->GetPropertyColorationColor((UObject*)Component, NewPropertyColor))

Engine/Source/Runtime/Engine/Private/StaticMeshRender.cpp

@@ -24,8 +24,6 @@
 #include "StaticMeshSceneProxy.h"
 #include "PhysicalMaterials/PhysicalMaterialMask.h"
 
-#include "Engine/LevelStreaming.h"
-#include "LevelUtils.h"
 #include "DistanceFieldAtlas.h"
 #include "MeshCardRepresentation.h"
 #include "Components/BrushComponent.h"
@@ -295,7 +293,6 @@ FStaticMeshSceneProxy::FStaticMeshSceneProxy(const FStaticMeshSceneProxyDesc& In
 	ClampedMinLOD = FMath::Clamp(EffectiveMinLOD, FirstAvailableLOD, RenderData->LODResources.Num() - 1);
 
 	SetWireframeColor(InProxyDesc.GetWireframeColor());
-	SetLevelColor(FLinearColor(1,1,1));
 	SetPropertyColor(FLinearColor(1,1,1));
 
 	// Copy the pointer to the volume data, async building of the data may modify the one on FStaticMeshLODResources while we are rendering
@@ -378,17 +375,6 @@ FStaticMeshSceneProxy::FStaticMeshSceneProxy(const FStaticMeshSceneProxyDesc& In
 #if STATICMESH_ENABLE_DEBUG_RENDERING
 	if( GIsEditor )
 	{
-		// Try to find a color for level coloration.
-		ULevel* Level = InProxyDesc.GetComponentLevel();
-		if (Level)
-		{
-			ULevelStreaming* LevelStreaming = FLevelUtils::FindStreamingLevel( Level );
-			if ( LevelStreaming )
-			{
-				SetLevelColor(LevelStreaming->LevelColor);
-			}
-		}
-
 		// Get a color for property coloration.
 		FColor TempPropertyColor;
 		if (GEngine->GetPropertyColorationColor( InProxyDesc.GetObjectForPropertyColoration(), TempPropertyColor ))

Engine/Source/Runtime/Engine/Private/WorldPartition/WorldPartitionLevelStreamingDynamic.cpp

@@ -186,6 +186,8 @@ void UWorldPartitionLevelStreamingDynamic::CreateRuntimeLevel()
 
 	// Attach ourself to Level cleanup to do our own cleanup
 	OnCleanupLevelDelegateHandle = RuntimeLevel->OnCleanupLevel.AddUObject(this, &UWorldPartitionLevelStreamingDynamic::OnCleanupLevel);
+
+	LevelColor = FLinearColor::MakeRandomSeededColor(GetTypeHash(GetName()));
 }
 
 /**

Engine/Source/Runtime/Engine/Public/PrimitiveSceneProxyDesc.h

@@ -215,6 +215,7 @@ struct FPrimitiveSceneProxyDesc
 	bool IsOwnerEditorOnly() const { return bIsOwnerEditorOnly; }
 
 #if WITH_EDITOR
+	FLinearColor GetLevelColor() const { return GetLevel() ? GetLevel()->LevelColor : FLinearColor::White; }
 	bool IsHiddenEd() const { return bIsHiddenEd; }
 	uint64 GetHiddenEditorViews() const { return HiddenEditorViews; }
 	bool IsOwnedByFoliage() const { return bIsOwnedByFoliage; }	

Engine/Source/Runtime/Landscape/Private/LandscapeRender.cpp

@@ -22,8 +22,6 @@ LandscapeRender.cpp: New terrain rendering
 #include "ShaderParameterUtils.h"
 #include "LandscapeEdit.h"
 #include "Engine/Level.h"
-#include "Engine/LevelStreaming.h"
-#include "LevelUtils.h"
 #include "Materials/MaterialExpressionTextureSample.h"
 #include "LandscapeMaterialInstanceConstant.h"
 #include "Engine/ShadowMapTexture2D.h"
@@ -1234,8 +1232,6 @@ FLandscapeComponentSceneProxy::FLandscapeComponentSceneProxy(ULandscapeComponent
 	LODIndexToMaterialIndex = InComponent->LODIndexToMaterialIndex;
 	check(LODIndexToMaterialIndex.Num() == MaxLOD + 1);
 
-	SetLevelColor(FLinearColor(1.f, 1.f, 1.f));
-			
 	HeightmapSubsectionOffsetU = 0;
 	HeightmapSubsectionOffsetV = 0;
 	if (HeightmapTexture)
@@ -1419,22 +1415,6 @@ FLandscapeComponentSceneProxy::FLandscapeComponentSceneProxy(ULandscapeComponent
 
 	Algo::Transform(AvailableMaterialInterfaces, MaterialRelevances, [FeatureLevel](UMaterialInterface* InMaterialInterface) { check(InMaterialInterface != nullptr); return InMaterialInterface->GetRelevance_Concurrent(FeatureLevel); });
 
-#if !(UE_BUILD_SHIPPING || UE_BUILD_TEST) || (UE_BUILD_SHIPPING && WITH_EDITOR)
-	if (GIsEditor)
-	{
-		// Try to find a color for level coloration.
-		if (Proxy)
-		{
-			ULevel* Level = Proxy->GetLevel();
-			ULevelStreaming* LevelStreaming = FLevelUtils::FindStreamingLevel(Level);
-			if (LevelStreaming)
-			{
-				SetLevelColor(LevelStreaming->LevelColor);
-			}
-		}
-	}
-#endif
-	
 	const int8 SubsectionSizeLog2 = static_cast<int8>(FMath::CeilLogTwo(InComponent->SubsectionSizeQuads + 1));
 	SharedBuffersKey = (SubsectionSizeLog2 & 0xf) | ((NumSubsections & 0xf) << 4) |	(XYOffsetmapTexture == nullptr ? 0 : 1 << 31);
 

Engine/Source/Runtime/Renderer/Private/BasePassRendering.cpp

@@ -1330,6 +1330,10 @@ void FDeferredShadingSceneRenderer::RenderBasePassInternal(
 	{
 		NaniteDebugViewMode = Nanite::EDebugViewMode::LightmapDensity;
 	}
+	else if (ViewFamily.EngineShowFlags.LevelColoration)
+	{
+		NaniteDebugViewMode = Nanite::EDebugViewMode::LevelColor;
+	}
 	else if (ViewFamily.UseDebugViewPS())
 	{
 	    switch (ViewFamily.GetDebugViewShaderMode())

Engine/Source/Runtime/Renderer/Private/Nanite/NaniteVisualize.h

@@ -36,6 +36,7 @@ enum class EDebugViewMode : uint8
 	Wireframe = 1,
 	ShaderComplexity = 2,
 	LightmapDensity = 3,
+	LevelColor = 4,
 };
 
 void RenderDebugViewMode(