vault backup: 2024-11-14 12:59:18

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--- a/03-UnrealEngine/Rendering/RenderingPipeline/Materials&MeshDraw/DynamicMeshDraw.md
+++ b/03-UnrealEngine/Rendering/RenderingPipeline/Materials&MeshDraw/DynamicMeshDraw.md
@@ -0,0 +1,8 @@
+---
+title: 未命名
+date: 2022-09-04 19:50:57
+excerpt: 
+tags: 
+rating: ⭐
+---
+可以使用DrawDynamicMeshPass()，实现在插件中使用MeshDraw绘制Pass。
--- a/03-UnrealEngine/Rendering/RenderingPipeline/Materials&MeshDraw/MeshDraw.md
+++ b/03-UnrealEngine/Rendering/RenderingPipeline/Materials&MeshDraw/MeshDraw.md
@@ -0,0 +1,258 @@
+---
+title: Untitled
+date: 2024-09-25 14:59:32
+excerpt: 
+tags: 
+rating: ⭐
+---
+# 前言
+可以使用DrawDynamicMeshPass()，实现在插件中使用MeshDraw绘制Pass。
+
+参考文章：
+- ***UE5，为HairStrands添加自定义深度与模板***:https://zhuanlan.zhihu.com/p/689578355
+
+# MeshDraw
+推荐学习：
+- CustomDepth
+- RenderBasePassInternal()
+- RenderAnisotropyPass()
+
+Shader推荐：
+- DepthOnlyVertexShader.usf
+- DepthOnlyPixelShader.usf
+
+# NaniteMeshDraw
+`Engine\Source\Runtime\Renderer\Private\Nanite\`NaniteMaterials.h & NaniteMaterials.cpp
+
+PS.使用的Shader必须是`FNaniteGlobalShader`的子类。
+
+## BasePass
+### DrawBasePass()
+该函数在FDeferredShadingSceneRenderer::RenderBasePassInternal()中调用。
+
+DrawNaniteMaterialPass() => SubmitNaniteIndirectMaterial()
+## PSO
+-  RDG 04 Graphics Pipeline State Initializer https://zhuanlan.zhihu.com/p/582020846 
+
+- FGraphicsPipelineStateInitializer
+	- FRHIDepthStencilState*           DepthStencilState
+	- FRHIBlendState*                       BlendState
+	- FRHIRasterizerState*                RasterizerState
+	- EPrimitiveType                           PrimitiveType
+	- FBoundShaderStateInput         BoundShaderState.VertexDeclarationRHI
+	- FBoundShaderStateInput         BoundShaderState.VertexShaderRHI
+	- FBoundShaderStateInput         BoundShaderState.PixelShaderRHI
+	- ……
+
+// 应用
+SetGraphicsPipelineState(RHICmdList, GraphicsPSOInit,0);
+
+## FMeshPassProcessorRenderState
+- FMeshPassProcessorRenderState
+	- FRHIBlendState*                         BlendState
+	- FRHIDepthStencilState*             DepthStencilState
+	- FExclusiveDepthStencil::Type    DepthStencilAccess
+	- FRHIUniformBuffer*                    ViewUniformBuffer
+	- FRHIUniformBuffer*                    InstancedViewUniformBuffer
+	- FRHIUniformBuffer*                    PassUniformBuffer
+	- FRHIUniformBuffer*                    NaniteUniformBuffer
+	- uint32                                          StencilRef = 0;
+
+### FRHIBlendState
+使用***FBlendStateInitializerRHI()*** 进行初始化。
+它定义了8个渲染对象，一般我们只用第一组，它的七个参数分别是：
+- Color
+	- Color Write Mask
+	- Color Blend 混合类型
+	- Color Src 混合因子
+	- Color Dest 混合因子
+- Alpha
+	- Alpha Blend 混合类型
+	- Alpha Src 混合因子
+	- Alpha Dest 混合因子
+
+```c++
+FRHIBlendState* CopyBlendState = TStaticBlendState<CW_RGB, BO_Add, BF_SourceAlpha, BF_InverseSourceAlpha, BO_Add, BF_Zero, BF_One>::GetRHI();
+```
+
+颜色写入蒙版：
+```c++
+enum EColorWriteMask
+{
+	CW_RED   = 0x01,
+	CW_GREEN = 0x02,
+	CW_BLUE  = 0x04,
+	CW_ALPHA = 0x08,
+
+	CW_NONE  = 0,
+	CW_RGB   = CW_RED | CW_GREEN | CW_BLUE,
+	CW_RGBA  = CW_RED | CW_GREEN | CW_BLUE | CW_ALPHA,
+	CW_RG    = CW_RED | CW_GREEN,
+	CW_BA    = CW_BLUE | CW_ALPHA,
+
+	EColorWriteMask_NumBits = 4,
+};
+```
+
+#### 混合运算
+混合运算符对于颜色混合方程和Alpha混合方程效果是一样的，这里就只用颜色混合方程来做讲解。
+
+| BlendOperation       | 颜色混合方程                                                                             |
+| -------------------- | ---------------------------------------------------------------------------------- |
+| BO_Add               | $$C=C_{src} \otimes F_{src} + C_{dst} \otimes F_{dst}Csrc⊗Fsrc+Cdst⊗Fdst$$     |
+| BO_Subtract          | $$C = C_{src} \otimes F_{src} - C_{dst} \otimes F_{dst}C=Csrc⊗Fsrc−Cdst⊗Fdst$$ |
+| BO_ReverseSubtract   | $$C = C_{dst} \otimes F_{dst} - C_{src} \otimes F_{src}C=Cdst⊗Fdst−Csrc⊗Fsrc$$ |
+| BO_Min               | $$C = Min(C_{src} , C_{dst} )C=Min(Csrc,Cdst)$$                                  |
+| BO_Max               | $$C = Max(C_{src} , C_{dst} )C=Max(Csrc,Cdst)$$                                  |
+| BO_Min和BO_Max忽略了混合因子 |                                                                                    |
+
+#### 混合因子
+
+| BlendFactor                   | 颜色混合因子                                                           | Alpha混合因子                |
+| ----------------------------- | ---------------------------------------------------------------- | ------------------------ |
+| BF_Zero                       | $$F = (0,0,0)F=(0,0,0)$$                                         | $$F=0F=0$$               |
+| BF_One                        | $$F=(1,1,1)F=(1,1,1)$$                                           | $$F=1F=1$$               |
+| BF_SourceColor                | $$F=(r_{src},g_{src},b_{src})F=(rsrc,gsrc,bsrc)$$             | –                        |
+| BF_InverseSourceColor         | $$F=(1-r_{src},1-g_{src},1-b_{src})F=(1−rsrc,1−gsrc,1−bsrc)$$ | –                        |
+| BF_SourceAlpha                | $$F=(a_{src},a_{src},a_{src})F=(asrc,asrc,asrc)$$             | $$F=a_{src}F=asrc$$     |
+| BF_InverseSourceAlpha         | $$F=(1-a_{src},1-a_{src},1-a_{src})F=(1−asrc,1−asrc,1−asrc)$$ | $$F=1-a_{src}F=1−asrc$$ |
+| BF_DestAlpha                  | $$F=(a_{dst},a_{dst},a_{dst})F=(adst,adst,adst)$$             | $$F=a_{dst}F=adst$$     |
+| BF_InverseDestAlpha           | $$F=(1-a_{dst},1-a_{dst},1-a_{dst})F=(1−adst,1−adst,1−adst)$$ | $$F=1-a_{dst}F=1−adst$$ |
+| BF_DestColor                  | $$F=(r_{dst},g_{dst},b_{dst})F=(rdst,gdst,bdst)$$             | –                        |
+| BF_InverseDestColor           | $$F=(1-r_{dst},1-g_{dst},1-b_{dst})F=(1−rdst,1−gdst,1−bdst)$$ | –                        |
+| BF_ConstantBlendFactor        | F=(r,g,b)F=(r,g,b)                                               | F=aF=a                   |
+| BF_InverseConstantBlendFactor | F=(1-r,1-g,1-b)F=(1−r,1−g,1−b)                                   | F=1-aF=1−a               |
+| BF_Source1Color               | 未知                                                               | 未知                       |
+| BF_InverseSource1Color        | 未知                                                               | 未知                       |
+| BF_Source1Alpha               | 未知                                                               | 未知                       |
+| BF_InverseSource1Alpha        | 未知                                                               | 未知                       |
+
+最后四个选项没有在DirectX中找到对应的选项，没有继续探究，前面的应该足够一般使用了。
+### FRHIDepthStencilState
+```c++
+TStaticDepthStencilState<
+		bEnableDepthWrite,          // 是否启用深度写入
+		DepthTest,                  // 深度测试比较函数
+		bEnableFrontFaceStencil,    // (正面)启用模板
+		FrontFaceStencilTest,       // (正面)模板测试操作
+		FrontFaceStencilFailStencilOp, //(正面)模板测试失败时如何更新模板缓冲区
+		FrontFaceDepthFailStencilOp,  //(正面)深度测试失败时如何更新模板缓冲区
+		FrontFacePassStencilOp,     //(正面)通过模板测试时如何更新模板缓冲区
+		bEnableBackFaceStencil,     // (背面)启用模板
+		BackFaceStencilTest,        // (背面)模板失败操作
+		BackFaceStencilFailStencilOp, //(背面)模板测试失败时如何更新模板缓冲区
+		BackFaceDepthFailStencilOp, //(背面)深度测试失败时如何更新模板缓冲区
+		BackFacePassStencilOp,      //(背面)通过模板测试时如何更新模板红冲去
+		StencilReadMask,            // 模板读取Mask
+		StencilWriteMask            // 模板写入Mask
+		>
+```
+
+```c++
+//一般使用这个
+TStaticDepthStencilState<true, CF_DepthNearOrEqual>::GetRHI();
+//CustomStencil中使用的
+TStaticDepthStencilState<true, CF_DepthNearOrEqual, true, CF_Always, SO_Keep, SO_Keep, SO_Replace, false, CF_Always, SO_Keep, SO_Keep, SO_Keep, 255, 255>::GetRHI()
+```
+
+#### DepthTest
+深度测试比较函数。
+```c++
+enum ECompareFunction
+{
+	CF_Less,
+	CF_LessEqual,
+	CF_Greater,
+	CF_GreaterEqual,
+	CF_Equal,
+	CF_NotEqual,
+	CF_Never, // 总是返回false
+	CF_Always, // 总是返回true
+
+	ECompareFunction_Num,
+	ECompareFunction_NumBits = 3,
+
+	// Utility enumerations
+	CF_DepthNearOrEqual		= (((int32)ERHIZBuffer::IsInverted != 0) ? CF_GreaterEqual : CF_LessEqual),
+	CF_DepthNear			= (((int32)ERHIZBuffer::IsInverted != 0) ? CF_Greater : CF_Less),
+	CF_DepthFartherOrEqual	= (((int32)ERHIZBuffer::IsInverted != 0) ? CF_LessEqual : CF_GreaterEqual),
+	CF_DepthFarther			= (((int32)ERHIZBuffer::IsInverted != 0) ? CF_Less : CF_Greater),
+};
+```
+
+```c++
+enum EStencilOp  
+{  
+    SO_Keep,  
+    SO_Zero,  
+    SO_Replace,  
+    SO_SaturatedIncrement,  
+    SO_SaturatedDecrement,  
+    SO_Invert,  
+    SO_Increment,  
+    SO_Decrement,  
+  
+    EStencilOp_Num,  
+    EStencilOp_NumBits = 3,  
+};
+```
+
+### CustomStencil
+#### InitCustomDepthStencilContext()
+根据当前平台是否支持使用ComputeShader直接输出结果（bComputeExport）、以及是否写入Stencil缓存，以此来创建不同的资源。最终输出FCustomDepthContext。
+```c++
+struct FCustomDepthContext  
+{  
+    FRDGTextureRef InputDepth = nullptr;  
+    FRDGTextureSRVRef InputStencilSRV = nullptr;  
+    FRDGTextureRef DepthTarget = nullptr;  
+    FRDGTextureRef StencilTarget = nullptr;  
+    bool bComputeExport = true;  
+};
+```
+
+#### EmitCustomDepthStencilTargets()
+根据bComputeExport，分别使用RDG的ComputeShader与PixelShader输出DepthStencil。 
+- CS使用FComputeShaderUtils::AddPass()
+- PS使用NaniteExportGBuffer.usf的**EmitCustomDepthStencilPS()**，FPixelShaderUtils::AddFullscreenPass()
+
+以**FEmitCustomDepthStencilPS**(NaniteExportGBuffer.usf)为例，额外输入的Nanite相关变量：
+- FSceneUniformParameters Scene
+- StructuredBuffer`<`FPackedView`>` InViews
+- ByteAddressBuffer VisibleClustersSWHW？
+- FIntVector4, PageConstants
+- Texture2D`<`UlongType`>`, VisBuffer64
+- ByteAddressBuffer MaterialSlotTable
+
+#### FinalizeCustomDepthStencil()
+替换输出的Depth&Stencil。
+
+# FViewInfo
+FViewInfo& ViewInfo
+- WriteView.bSceneHasSkyMaterial |= bSceneHasSkyMaterial;
+- WriteView.bHasSingleLayerWaterMaterial |= bHasSingleLayerWaterMaterial;
+- WriteView.bHasCustomDepthPrimitives |= bHasCustomDepthPrimitives;
+- WriteView.bHasDistortionPrimitives |= bHasDistortionPrimitives;
+- WriteView.bUsesCustomDepth |= bUsesCustomDepth;  
+- WriteView.bUsesCustomStencil |= bUsesCustomStencil;
+
+- FRelevancePacket::Finalize()
+
+相关性：
+- 相关性定义
+	- FStaticMeshBatchRelevance
+	- FMaterialRelevance
+- View相关计算
+	- FViewInfo::Init()
+	- FRelevancePacket
+	- FRelevancePacket::Finalize()
+
+# 相关宏定义
+- SCOPE_CYCLE_COUNTER(STAT_BasePassDrawTime);：
+	- DECLARE_CYCLE_STAT_EXTERN(TEXT("Base pass drawing"),STAT_BasePassDrawTime,STATGROUP_SceneRendering, RENDERCORE_API);
+	- DEFINE_STAT(STAT_BasePassDrawTime);
+- DEFINE_GPU_STAT(NaniteBasePass);
+	- DECLARE_GPU_STAT_NAMED_EXTERN(NaniteBasePass, TEXT("Nanite BasePass"));
+- GET_STATID(STAT_CLP_BasePass)
+	- FRDGParallelCommandListSet ParallelCommandListSet(InPass, RHICmdList, GET_STATID(STAT_CLP_BasePass), View, FParallelCommandListBindings(PassParameters));
+	- DECLARE_CYCLE_STAT(TEXT("BasePass"), STAT_CLP_BasePass, STATGROUP_ParallelCommandListMarkers);
--- a/03-UnrealEngine/Rendering/RenderingPipeline/Materials&MeshDraw/UE5.5
+++ b/03-UnrealEngine/Rendering/RenderingPipeline/Materials&MeshDraw/UE5.5
@@ -0,0 +1,91 @@
+---
+title: Untitled
+date: 2024-11-14 12:19:36
+excerpt: 
+tags: 
+rating: ⭐
+---
+# 前言
+探索思路：
+- [ ] SceneProxy收集机制的改变。
+- [ ] GetDynamicMeshElements的调用方式。
+- [ ] 在SendRenderDynamicData_Concurrent中添加（模仿USkeletalMeshComponent::SendRenderDynamicData_Concurrent()与FDebugSkelMeshSceneProxy）
+
+# GetDynamicMeshElements
+看得出主要在FDynamicMeshElementContext::GatherDynamicMeshElementsForPrimitive()中调用Primitive->Proxy->GetDynamicMeshElements()。
+
+```c++
+UE::Tasks::FTask FDynamicMeshElementContext::LaunchAsyncTask(FDynamicPrimitiveIndexQueue* PrimitiveIndexQueue, UE::Tasks::ETaskPriority TaskPriority)
+{
+	return Pipe.Launch(UE_SOURCE_LOCATION, [this, PrimitiveIndexQueue]
+	{
+		FOptionalTaskTagScope Scope(ETaskTag::EParallelRenderingThread);
+		FDynamicPrimitiveIndex PrimitiveIndex;
+
+		while (PrimitiveIndexQueue->Pop(PrimitiveIndex))
+		{
+			GatherDynamicMeshElementsForPrimitive(Primitives[PrimitiveIndex.Index], PrimitiveIndex.ViewMask);
+		}
+
+#if WITH_EDITOR
+		while (PrimitiveIndexQueue->PopEditor(PrimitiveIndex))
+		{
+			GatherDynamicMeshElementsForEditorPrimitive(Primitives[PrimitiveIndex.Index], PrimitiveIndex.ViewMask);
+		}
+#endif
+	}, TaskPriority);
+}
+
+void FDynamicMeshElementContext::GatherDynamicMeshElementsForPrimitive(FPrimitiveSceneInfo* Primitive, uint8 ViewMask)
+{
+	SCOPED_NAMED_EVENT(DynamicPrimitive, FColor::Magenta);
+
+	TArray<int32, TInlineAllocator<4>> MeshBatchCountBefore;
+	MeshBatchCountBefore.SetNumUninitialized(Views.Num());
+	for (int32 ViewIndex = 0; ViewIndex < Views.Num(); ViewIndex++)
+	{
+		MeshBatchCountBefore[ViewIndex] = MeshCollector.GetMeshBatchCount(ViewIndex);
+	}
+
+	MeshCollector.SetPrimitive(Primitive->Proxy, Primitive->DefaultDynamicHitProxyId);
+
+	// If Custom Render Passes aren't in use, there will be only one group, which is the common case.
+	if (ViewFamilyGroups.Num() == 1 || Primitive->Proxy->SinglePassGDME())
+	{
+		Primitive->Proxy->GetDynamicMeshElements(FirstViewFamily.AllViews, FirstViewFamily, ViewMask, MeshCollector);
+	}
+	else
+	{
+		for (FViewFamilyGroup& Group : ViewFamilyGroups)
+		{
+			if (uint8 MaskedViewMask = ViewMask & Group.ViewSubsetMask)
+			{
+				Primitive->Proxy->GetDynamicMeshElements(FirstViewFamily.AllViews, *Group.Family, MaskedViewMask, MeshCollector);
+			}
+		}
+	}
+
+	for (int32 ViewIndex = 0; ViewIndex < Views.Num(); ViewIndex++)
+	{
+		FViewInfo& View = *Views[ViewIndex];
+
+		if (ViewMask & (1 << ViewIndex))
+		{
+			FDynamicPrimitive& DynamicPrimitive = DynamicPrimitives.Emplace_GetRef();
+			DynamicPrimitive.PrimitiveIndex = Primitive->GetIndex();
+			DynamicPrimitive.ViewIndex = ViewIndex;
+			DynamicPrimitive.StartElementIndex = MeshBatchCountBefore[ViewIndex];
+			DynamicPrimitive.EndElementIndex = MeshCollector.GetMeshBatchCount(ViewIndex);
+		}
+	}
+}
+```
+
+# SendRenderDynamicData_Concurrent
+
+## FDebugSkelMeshSceneProxy::GetDynamicMeshElements
+
+
+# 其他？
+
+MeshBuilderSurface.GetMesh(GetLocalToWorld(), MatProxySurface, SDPG_Foreground, false, false, ViewIndex, Collector);
--- a/03-UnrealEngine/Rendering/RenderingPipeline/Materials&MeshDraw/材质中PassSwitch节点实现方式.md
+++ b/03-UnrealEngine/Rendering/RenderingPipeline/Materials&MeshDraw/材质中PassSwitch节点实现方式.md
@@ -0,0 +1,154 @@
+---
+title: Untitled
+date: 2024-09-23 19:47:03
+excerpt: 
+tags: 
+rating: ⭐
+---
+# ShadowPassSwitch
+## Cpp
+MaterialExpressionShadowReplace.h
+
+MaterialExpressions.cpp
+```c++
+int32 UMaterialExpressionShadowReplace::Compile(class FMaterialCompiler* Compiler, int32 OutputIndex)
+{
+	if (!Default.GetTracedInput().Expression)
+	{
+		return Compiler->Errorf(TEXT("Missing input Default"));
+	}
+	else if (!Shadow.GetTracedInput().Expression)
+	{
+		return Compiler->Errorf(TEXT("Missing input Shadow"));
+	}
+	else
+	{
+		const int32 Arg1 = Default.Compile(Compiler);
+		const int32 Arg2 = Shadow.Compile(Compiler);
+		return Compiler->ShadowReplace(Arg1, Arg2);
+	}
+}
+```
+
+MaterialCompiler.h => **HLSLMaterialTranslator.cpp**
+```c++
+int32 FHLSLMaterialTranslator::ShadowReplace(int32 Default, int32 Shadow)  
+{  
+    return GenericSwitch(TEXT("GetShadowReplaceState()"), Shadow, Default);  
+}
+```
+
+```c++
+int32 FHLSLMaterialTranslator::GenericSwitch(const TCHAR* SwitchExpressionText, int32 IfTrue, int32 IfFalse)
+{
+	if (IfTrue == INDEX_NONE || IfFalse == INDEX_NONE)
+	{
+		return INDEX_NONE;
+	}
+
+	// exactly the same inputs on both sides - no need to generate anything extra
+	if (IfTrue == IfFalse)
+	{
+		return IfTrue;
+	}
+
+	FMaterialUniformExpression* IfTrueExpression = GetParameterUniformExpression(IfTrue);
+	FMaterialUniformExpression* IfFalseExpression = GetParameterUniformExpression(IfFalse);
+	if (IfTrueExpression &&
+		IfFalseExpression &&
+		IfTrueExpression->IsConstant() &&
+		IfFalseExpression->IsConstant())
+	{
+		FMaterialRenderContext DummyContext(nullptr, *Material, nullptr);
+		FLinearColor IfTrueValue;
+		FLinearColor IfFalseValue;
+		IfTrueExpression->GetNumberValue(DummyContext, IfTrueValue);
+		IfFalseExpression->GetNumberValue(DummyContext, IfFalseValue);
+		if (IfTrueValue == IfFalseValue)
+		{
+			// If both inputs are wired to == constant values, avoid adding the runtime switch
+			// This will avoid breaking various offline checks for constant values
+			return IfTrue;
+		}
+	}
+
+	// Both branches of '?:' need to be the same type
+	const EMaterialValueType ResultType = GetArithmeticResultType(IfTrue, IfFalse);
+	const FString IfTrueCode = CoerceParameter(IfTrue, ResultType);
+	const FString IfFalseCode = CoerceParameter(IfFalse, ResultType);
+	
+	if (IsLWCType(ResultType))
+	{
+		AddLWCFuncUsage(ELWCFunctionKind::Other);
+		return AddCodeChunk(ResultType, TEXT("LWCSelect(%s, %s, %s)"), SwitchExpressionText, *IfTrueCode, *IfFalseCode);
+	}
+	else
+	{
+		return AddCodeChunk(ResultType, TEXT("(%s ? (%s) : (%s))"), SwitchExpressionText, *IfTrueCode, *IfFalseCode);
+	}
+}
+```
+
+>可以看得出最终会编译成(%s ? (%s) : (%s))，也就是 GetShadowReplaceState() ? True的Shader ： False时的Shader。
+
+## Shader
+### Common.ush
+```c++
+// NOTE: The raytraced implementation of the ShadowPassSwitch node is kept in RayTracingShaderUtils.ush as it needs to access per ray information.  
+#if RAYHITGROUPSHADER == 0  
+// Experimental way to allow adjusting the OpacityMask for shadow map rendering of masked materials.  
+// This is exposed via the ShadowPassSwitch material node. This can also be accessed with a Custom  
+// material node. If this turns out to be very useful we can expose as MaterialFunction  
+// and potentially expose other queries as well (e.g. SkeletalMesh, HitProxy, ).  
+// @return 0:no, 1:yes  
+bool GetShadowReplaceState()  
+{  
+#if SHADOW_DEPTH_SHADER  
+    return true;  
+#else  
+    return false;  
+#endif  
+}  
+  
+float IsShadowDepthShader()  
+{  
+    return GetShadowReplaceState() ? 1.0f : 0.0f;  
+}  
+  
+#endif // RAYHITGROUPSHADER == 0
+```
+
+可以看得出主要通过**SHADOW_DEPTH_SHADER**宏进行判断，而渲染阴影的Shader ShadowDepthVertexShader.usf&ShadowDepthPixelShader.usf都定义该宏为1。
+
+### NaniteRasterizer.usf
+```c++
+// This must be defined before including Common.ush (see GetShadowReplaceState)  
+#define SHADOW_DEPTH_SHADER DEPTH_ONLY
+```
+在NaniteCullRaster.cpp中DEPTH_ONLY设置为1。
+
+### RayTracingShaderUtils.ush
+光追相关
+```c++
+#ifndef RAYHITGROUPSHADER  
+#error "This header should only be included in raytracing contexts"  
+#endif  
+  
+#ifndef PATH_TRACING // Path Tracing has a similar implemental with a slightly different set of flags  
+  
+#include "RayTracingCommon.ush"  
+  
+static int CurrentPayloadInputFlags = 0;  
+  
+bool GetShadowReplaceState()  
+{  
+    return (CurrentPayloadInputFlags & RAY_TRACING_PAYLOAD_INPUT_FLAG_SHADOW_RAY) != 0;  
+}  
+  
+float IsShadowDepthShader()  
+{  
+    return GetShadowReplaceState() ? 1.0f : 0.0f;  
+}  
+  
+#endif
+```