vault backup: 2024-02-06 21:26:28
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6
.obsidian/community-plugins.json
vendored
6
.obsidian/community-plugins.json
vendored
@ -29,10 +29,10 @@
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"obsidian-hover-editor",
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"obsidian-admonition",
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"workspaces-plus",
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"Enhanced-editing",
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"obsidian42-brat",
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"remotely-save",
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"table-editor-obsidian",
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"dataview",
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"obsidian-view-mode-by-frontmatter"
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"obsidian-view-mode-by-frontmatter",
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"Enhanced-editing",
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"table-editor-obsidian"
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]
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@ -126,6 +126,14 @@
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"lastUpdated": 1707140527615
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}
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}
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},
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"VertexBufferSRV": {
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"VertexBufferSRV": {
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"currentFile": {
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"count": 1,
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"lastUpdated": 1707223827335
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}
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}
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}
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}
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}
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@ -8,7 +8,6 @@ rating: ⭐
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# 前言
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原文地址:https://www.cnblogs.com/timlly/p/15092257.html
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# FShader
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```c++
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class FShader
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@ -894,3 +893,872 @@ IMPLEMENT_VERTEX_FACTORY_PARAMETER_TYPE(FLocalVertexFactory, SF_Vertex, FLocalVe
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// 实现FLocalVertexFactory.
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IMPLEMENT_VERTEX_FACTORY_TYPE_EX(FLocalVertexFactory,"/Engine/Private/LocalVertexFactory.ush",true,true,true,true,true,true,true);
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```
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下面进入CableComponent相关类型关于FLocalVertexFactory的使用：
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```c++
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// Engine\Plugins\Runtime\CableComponent\Source\CableComponent\Private\CableComponent.cpp
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class FCableSceneProxy final : public FPrimitiveSceneProxy
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{
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public:
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FCableSceneProxy(UCableComponent* Component)
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: FPrimitiveSceneProxy(Component)
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, Material(NULL)
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// 构造顶点工厂.
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, VertexFactory(GetScene().GetFeatureLevel(), "FCableSceneProxy")
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(......)
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{
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// 利用顶点工厂初始化缓冲区.
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VertexBuffers.InitWithDummyData(&VertexFactory, GetRequiredVertexCount());
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(......)
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}
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virtual ~FCableSceneProxy()
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{
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// 释放顶点工厂.
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VertexFactory.ReleaseResource();
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(......)
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}
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// 构建Cable网格.
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void BuildCableMesh(const TArray<FVector>& InPoints, TArray<FDynamicMeshVertex>& OutVertices, TArray<int32>& OutIndices)
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{
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(......)
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}
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// 设置动态数据(渲染线程调用)
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void SetDynamicData_RenderThread(FCableDynamicData* NewDynamicData)
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{
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// 释放旧数据.
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if(DynamicData)
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{
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delete DynamicData;
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DynamicData = NULL;
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}
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DynamicData = NewDynamicData;
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// 从Cable点构建顶点.
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TArray<FDynamicMeshVertex> Vertices;
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TArray<int32> Indices;
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BuildCableMesh(NewDynamicData->CablePoints, Vertices, Indices);
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// 填充顶点缓冲区数据.
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for (int i = 0; i < Vertices.Num(); i++)
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{
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const FDynamicMeshVertex& Vertex = Vertices[i];
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VertexBuffers.PositionVertexBuffer.VertexPosition(i) = Vertex.Position;
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VertexBuffers.StaticMeshVertexBuffer.SetVertexTangents(i, Vertex.TangentX.ToFVector(), Vertex.GetTangentY(), Vertex.TangentZ.ToFVector());
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VertexBuffers.StaticMeshVertexBuffer.SetVertexUV(i, 0, Vertex.TextureCoordinate[0]);
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VertexBuffers.ColorVertexBuffer.VertexColor(i) = Vertex.Color;
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}
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// 更新顶点缓冲区数据到RHI.
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{
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auto& VertexBuffer = VertexBuffers.PositionVertexBuffer;
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void* VertexBufferData = RHILockVertexBuffer(VertexBuffer.VertexBufferRHI, 0, VertexBuffer.GetNumVertices() * VertexBuffer.GetStride(), RLM_WriteOnly);
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FMemory::Memcpy(VertexBufferData, VertexBuffer.GetVertexData(), VertexBuffer.GetNumVertices() * VertexBuffer.GetStride());
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RHIUnlockVertexBuffer(VertexBuffer.VertexBufferRHI);
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}
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(......)
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}
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virtual void GetDynamicMeshElements(const TArray<const FSceneView*>& Views, const FSceneViewFamily& ViewFamily, uint32 VisibilityMap, FMeshElementCollector& Collector) const override
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{
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(......)
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for (int32 ViewIndex = 0; ViewIndex < Views.Num(); ViewIndex++)
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{
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if (VisibilityMap & (1 << ViewIndex))
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{
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const FSceneView* View = Views[ViewIndex];
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// 构造FMeshBatch实例.
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FMeshBatch& Mesh = Collector.AllocateMesh();
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// 将顶点工厂实例传给FMeshBatch实例.
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Mesh.VertexFactory = &VertexFactory;
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(......)
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Collector.AddMesh(ViewIndex, Mesh);
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}
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}
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}
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(......)
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private:
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// 材质
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UMaterialInterface* Material;
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// 顶点和索引缓冲.
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FStaticMeshVertexBuffers VertexBuffers;
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FCableIndexBuffer IndexBuffer;
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// 顶点工厂.
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FLocalVertexFactory VertexFactory;
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// 动态数据.
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FCableDynamicData* DynamicData;
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(......)
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};
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```
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主要步骤：
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1. 在构造函数中初始化LocalVertexFactory成员变量。
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2. SetDynamicData_RenderThread()
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1. 通过控制点构建CableMesh顶点数据。
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2. 填充顶点缓冲区数据。FStaticMeshVertexBuffers VertexBuffers
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1. PositionVertexBuffer.VertexPosition
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2. StaticMeshVertexBuffer.SetVertexTangents
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3. StaticMeshVertexBuffer.SetVertexUV
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4. ColorVertexBuffer.VertexColor
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3. 更新IndexBufferData到RHI。
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3. GetDynamicMeshElements()：将顶点工厂实例传给FMeshBatch实例
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1. FMeshBatch& Mesh = Collector.AllocateMesh();
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2. Mesh.VertexFactory = &VertexFactory;
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3. Collector.AddMesh(ViewIndex, Mesh);
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不过，无论是使用已有的还是自定义的顶点工厂，顶点工厂的顶点声明的顺序、类型、组件数量和插槽需要和HLSL层的FVertexFactoryInput保持一致。比如说FLocalVertexFactory::InitRHI的顶点声明顺序是位置、切线、颜色、纹理坐标、光照图，那么我们进入FLocalVertexFactory对应的HLSL文件（由IMPLEMENT_VERTEX_FACTORY_TYPE等宏指定）看看：
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```c++
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// Engine\Shaders\Private\LocalVertexFactory.ush
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// 局部顶点工厂对应的输入结构体.
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struct FVertexFactoryInput
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{
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// 位置
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float4 Position : ATTRIBUTE0;
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// 切线和颜色
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#if !MANUAL_VERTEX_FETCH
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#if METAL_PROFILE
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float3 TangentX : ATTRIBUTE1;
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// TangentZ.w contains sign of tangent basis determinant
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float4 TangentZ : ATTRIBUTE2;
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float4 Color : ATTRIBUTE3;
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#else
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half3 TangentX : ATTRIBUTE1;
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// TangentZ.w contains sign of tangent basis determinant
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half4 TangentZ : ATTRIBUTE2;
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half4 Color : ATTRIBUTE3;
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#endif
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#endif
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// 纹理坐标
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#if NUM_MATERIAL_TEXCOORDS_VERTEX
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#if !MANUAL_VERTEX_FETCH
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#if GPUSKIN_PASS_THROUGH
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// These must match GPUSkinVertexFactory.usf
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float2 TexCoords[NUM_MATERIAL_TEXCOORDS_VERTEX] : ATTRIBUTE4;
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#if NUM_MATERIAL_TEXCOORDS_VERTEX > 4
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#error Too many texture coordinate sets defined on GPUSkin vertex input. Max: 4.
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#endif
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#else
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#if NUM_MATERIAL_TEXCOORDS_VERTEX > 1
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float4 PackedTexCoords4[NUM_MATERIAL_TEXCOORDS_VERTEX/2] : ATTRIBUTE4;
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#endif
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#if NUM_MATERIAL_TEXCOORDS_VERTEX == 1
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float2 PackedTexCoords2 : ATTRIBUTE4;
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#elif NUM_MATERIAL_TEXCOORDS_VERTEX == 3
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float2 PackedTexCoords2 : ATTRIBUTE5;
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#elif NUM_MATERIAL_TEXCOORDS_VERTEX == 5
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float2 PackedTexCoords2 : ATTRIBUTE6;
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#elif NUM_MATERIAL_TEXCOORDS_VERTEX == 7
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float2 PackedTexCoords2 : ATTRIBUTE7;
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#endif
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#endif
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#endif
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#elif USE_PARTICLE_SUBUVS && !MANUAL_VERTEX_FETCH
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float2 TexCoords[1] : ATTRIBUTE4;
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#endif
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(......)
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};
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```
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因此可知，FVertexFactoryInput结构体的数据顺序和FLocalVertexFactory的顶点声明是一一对应的。
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# ShaderMap
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ShaderMap的作用是**存储编译后的shader代码**，分为FGlobalShaderMap、FMaterialShaderMap、FMeshMaterialShaderMap三种类型。
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- FGlobalShaderMap：FGlobalShaderMap保存并管理着所有编译好的FGlobalShader代码。（**没有材质和顶点工程的**）
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- FMaterialShaderMap：存储和管理着一组FMaterialShader实例的对象。（**额外关联一个材质和一个顶点工厂**）
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- 因此可以找到，每个FMaterial都有一个FMaterialShaderMap（游戏线程一个，渲染线程一个），如果要获取FMaterial的指定类型的Shader，就需要从该FMaterial的FMaterialShaderMap实例中获取，从而完成了它们之间的链接。
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- FMeshMaterialShaderMap：存储和管理FMeshMaterialShader。
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### 编译相关代码
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如果需要了解编译过程可以查看`RecompileShaders`命令。
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```c++
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// Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp
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// 引擎预初始化.
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int32 FEngineLoop::PreInitPreStartupScreen(const TCHAR* CmdLine)
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{
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(......)
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// 是否开启shader编译, 一般情况下都会开启.
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bool bEnableShaderCompile = !FParse::Param(FCommandLine::Get(), TEXT("NoShaderCompile"));
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(......)
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if (bEnableShaderCompile && !IsRunningDedicatedServer() && !bIsCook)
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{
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(......)
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// 编译GlobalShaderMap
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CompileGlobalShaderMap(false);
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(......)
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}
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(......)
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}
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// Engine\Source\Runtime\Engine\Private\ShaderCompiler\ShaderCompiler.cpp
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void CompileGlobalShaderMap(EShaderPlatform Platform, const ITargetPlatform* TargetPlatform, bool bRefreshShaderMap)
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{
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(......)
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// 如果对应平台的GlobalShaderMap未创建, 则创建之.
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if (!GGlobalShaderMap[Platform])
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{
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(......)
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// 创建对应平台的FGlobalShaderMap.
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GGlobalShaderMap[Platform] = new FGlobalShaderMap(Platform);
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// Cooked模式.
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if (FPlatformProperties::RequiresCookedData())
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{
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(......)
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}
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// Uncooked模式
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else
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{
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// FGlobalShaderMap的id.
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FGlobalShaderMapId ShaderMapId(Platform);
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const int32 ShaderFilenameNum = ShaderMapId.GetShaderFilenameToDependeciesMap().Num();
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const float ProgressStep = 25.0f / ShaderFilenameNum;
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TArray<uint32> AsyncDDCRequestHandles;
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AsyncDDCRequestHandles.SetNum(ShaderFilenameNum);
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int32 HandleIndex = 0;
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// 提交DDC请求.
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for (const auto& ShaderFilenameDependencies : ShaderMapId.GetShaderFilenameToDependeciesMap())
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{
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SlowTask.EnterProgressFrame(ProgressStep);
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const FString DataKey = GetGlobalShaderMapKeyString(ShaderMapId, Platform, TargetPlatform, ShaderFilenameDependencies.Value);
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AsyncDDCRequestHandles[HandleIndex] = GetDerivedDataCacheRef().GetAsynchronous(*DataKey, TEXT("GlobalShaderMap"_SV));
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++HandleIndex;
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}
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// 处理已经结束的DDC请求.
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TArray<uint8> CachedData;
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HandleIndex = 0;
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for (const auto& ShaderFilenameDependencies : ShaderMapId.GetShaderFilenameToDependeciesMap())
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{
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SlowTask.EnterProgressFrame(ProgressStep);
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CachedData.Reset();
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GetDerivedDataCacheRef().WaitAsynchronousCompletion(AsyncDDCRequestHandles[HandleIndex]);
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if (GetDerivedDataCacheRef().GetAsynchronousResults(AsyncDDCRequestHandles[HandleIndex], CachedData))
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{
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FMemoryReader MemoryReader(CachedData);
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GGlobalShaderMap[Platform]->AddSection(FGlobalShaderMapSection::CreateFromArchive(MemoryReader));
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}
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else
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{
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// 没有在DDC中找到, 忽略之.
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}
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++HandleIndex;
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}
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}
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// 如果有shader没有被加载, 编译之.
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VerifyGlobalShaders(Platform, bLoadedFromCacheFile);
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// 创建所有着色器.
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if (GCreateShadersOnLoad && Platform == GMaxRHIShaderPlatform)
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{
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GGlobalShaderMap[Platform]->BeginCreateAllShaders();
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}
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}
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}
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```
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# Shader调试
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修改`Engine\Config\ConsoleVariables.ini`配置
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- r.ShaderDevelopmentMode=1 获得关于着色器编译的详细日志和错误重试的机会。
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- r.DumpShaderDebugInfo=1 将编译的所有着色器的文件保存到磁盘ProjectName/Saved/ShaderDebugInfo的目录。包含源文件、预处理后的版本、一个批处理文件（用于使用编译器等效的命令行选项来编译预处理版本）。
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- r.DumpShaderDebugShortNames=1 保存的Shader路径将被精简。
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- r.Shaders.Optimize=0 禁用着色器优化，使得shader的调试信息被保留。
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- r.Shaders.KeepDebugInfo=1 保留调试信息，配合RenderDoc等截帧工具时特别有用。
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- r.Shaders.SkipCompression=1 忽略shader压缩，可以节省调试shader的时间。
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另外，如果修改了Shader的某些文件（如BasePassPixelShader.ush），不需要重启UE编辑器，可以在控制台输入`RecompileShaders`命令重新编译指定的shader文件。其中`RecompileShaders`的具体含义如下：
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||||
- RecompileShaders all 编译源码有修改的所有shader，包含global、material、meshmaterial。
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||||
- RecompileShaders changed 编译源码有修改的shader。
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- RecompileShaders global 编译源码有修改的global shader。
|
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- RecompileShaders material 编译源码有修改的material shader。
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- RecompileShaders material 编译指定名称的材质。
|
||||
- RecompileShaders 编译指定路径的shader源文件。
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||||
# 案例
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||||
新增加FVertexFactory子类的过程如下：
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```c++
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// FMyVertexFactory.h
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||||
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// 声明顶点工厂着色器参数.
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BEGIN_GLOBAL_SHADER_PARAMETER_STRUCT(FMyVertexFactoryParameters, )
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SHADER_PARAMETER(FVector4, Color)
|
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END_GLOBAL_SHADER_PARAMETER_STRUCT()
|
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|
||||
// 声明类型.
|
||||
typedef TUniformBufferRef<FMyVertexFactoryParameters> FMyVertexFactoryBufferRef;
|
||||
|
||||
// 索引缓冲.
|
||||
class FMyMeshIndexBuffer : public FIndexBuffer
|
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{
|
||||
public:
|
||||
FMyMeshIndexBuffer(int32 InNumQuadsPerSide) : NumQuadsPerSide(InNumQuadsPerSide) {}
|
||||
|
||||
void InitRHI() override
|
||||
{
|
||||
if (NumQuadsPerSide < 256)
|
||||
{
|
||||
IndexBufferRHI = CreateIndexBuffer<uint16>();
|
||||
}
|
||||
else
|
||||
{
|
||||
IndexBufferRHI = CreateIndexBuffer<uint32>();
|
||||
}
|
||||
}
|
||||
|
||||
int32 GetIndexCount() const { return NumIndices; };
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||||
|
||||
private:
|
||||
template <typename IndexType>
|
||||
FIndexBufferRHIRef CreateIndexBuffer()
|
||||
{
|
||||
TResourceArray<IndexType, INDEXBUFFER_ALIGNMENT> Indices;
|
||||
|
||||
// 分配顶点索引内存.
|
||||
Indices.Reserve(NumQuadsPerSide * NumQuadsPerSide * 6);
|
||||
|
||||
// 用Morton顺序构建索引缓冲, 以更好地重用顶点.
|
||||
for (int32 Morton = 0; Morton < NumQuadsPerSide * NumQuadsPerSide; Morton++)
|
||||
{
|
||||
int32 SquareX = FMath::ReverseMortonCode2(Morton);
|
||||
int32 SquareY = FMath::ReverseMortonCode2(Morton >> 1);
|
||||
|
||||
bool ForwardDiagonal = false;
|
||||
|
||||
if (SquareX % 2)
|
||||
{
|
||||
ForwardDiagonal = !ForwardDiagonal;
|
||||
}
|
||||
if (SquareY % 2)
|
||||
{
|
||||
ForwardDiagonal = !ForwardDiagonal;
|
||||
}
|
||||
|
||||
int32 Index0 = SquareX + SquareY * (NumQuadsPerSide + 1);
|
||||
int32 Index1 = Index0 + 1;
|
||||
int32 Index2 = Index0 + (NumQuadsPerSide + 1);
|
||||
int32 Index3 = Index2 + 1;
|
||||
|
||||
Indices.Add(Index3);
|
||||
Indices.Add(Index1);
|
||||
Indices.Add(ForwardDiagonal ? Index2 : Index0);
|
||||
Indices.Add(Index0);
|
||||
Indices.Add(Index2);
|
||||
Indices.Add(ForwardDiagonal ? Index1 : Index3);
|
||||
}
|
||||
|
||||
NumIndices = Indices.Num();
|
||||
const uint32 Size = Indices.GetResourceDataSize();
|
||||
const uint32 Stride = sizeof(IndexType);
|
||||
|
||||
// Create index buffer. Fill buffer with initial data upon creation
|
||||
FRHIResourceCreateInfo CreateInfo(&Indices);
|
||||
return RHICreateIndexBuffer(Stride, Size, BUF_Static, CreateInfo);
|
||||
}
|
||||
|
||||
int32 NumIndices = 0;
|
||||
const int32 NumQuadsPerSide = 0;
|
||||
};
|
||||
|
||||
// 顶点索引.
|
||||
class FMyMeshVertexBuffer : public FVertexBuffer
|
||||
{
|
||||
public:
|
||||
FMyMeshVertexBuffer(int32 InNumQuadsPerSide) : NumQuadsPerSide(InNumQuadsPerSide) {}
|
||||
|
||||
virtual void InitRHI() override
|
||||
{
|
||||
const uint32 NumVertsPerSide = NumQuadsPerSide + 1;
|
||||
|
||||
NumVerts = NumVertsPerSide * NumVertsPerSide;
|
||||
|
||||
FRHIResourceCreateInfo CreateInfo;
|
||||
void* BufferData = nullptr;
|
||||
VertexBufferRHI = RHICreateAndLockVertexBuffer(sizeof(FVector4) * NumVerts, BUF_Static, CreateInfo, BufferData);
|
||||
FVector4* DummyContents = (FVector4*)BufferData;
|
||||
|
||||
for (uint32 VertY = 0; VertY < NumVertsPerSide; VertY++)
|
||||
{
|
||||
FVector4 VertPos;
|
||||
VertPos.Y = (float)VertY / NumQuadsPerSide - 0.5f;
|
||||
|
||||
for (uint32 VertX = 0; VertX < NumVertsPerSide; VertX++)
|
||||
{
|
||||
VertPos.X = (float)VertX / NumQuadsPerSide - 0.5f;
|
||||
|
||||
DummyContents[NumVertsPerSide * VertY + VertX] = VertPos;
|
||||
}
|
||||
}
|
||||
|
||||
RHIUnlockVertexBuffer(VertexBufferRHI);
|
||||
}
|
||||
|
||||
int32 GetVertexCount() const { return NumVerts; }
|
||||
|
||||
private:
|
||||
int32 NumVerts = 0;
|
||||
const int32 NumQuadsPerSide = 0;
|
||||
};
|
||||
|
||||
// 顶点工厂.
|
||||
class FMyVertexFactory : public FVertexFactory
|
||||
{
|
||||
DECLARE_VERTEX_FACTORY_TYPE(FMyVertexFactory);
|
||||
|
||||
public:
|
||||
using Super = FVertexFactory;
|
||||
|
||||
FMyVertexFactory(ERHIFeatureLevel::Type InFeatureLevel);
|
||||
~FMyVertexFactory();
|
||||
|
||||
virtual void InitRHI() override;
|
||||
virtual void ReleaseRHI() override;
|
||||
|
||||
static bool ShouldCompilePermutation(const FVertexFactoryShaderPermutationParameters& Parameters);
|
||||
static void ModifyCompilationEnvironment(const FVertexFactoryShaderPermutationParameters& Parameters, FShaderCompilerEnvironment& OutEnvironment);
|
||||
static void ValidateCompiledResult(const FVertexFactoryType* Type, EShaderPlatform Platform, const FShaderParameterMap& ParameterMap, TArray<FString>& OutErrors);
|
||||
|
||||
inline const FUniformBufferRHIRef GetMyVertexFactoryUniformBuffer() const { return UniformBuffer; }
|
||||
|
||||
private:
|
||||
void SetupUniformData();
|
||||
|
||||
FMyMeshVertexBuffer* VertexBuffer = nullptr;
|
||||
FMyMeshIndexBuffer* IndexBuffer = nullptr;
|
||||
|
||||
FMyVertexFactoryBufferRef UniformBuffer;
|
||||
};
|
||||
|
||||
|
||||
// FMyVertexFactory.cpp
|
||||
#include "ShaderParameterUtils.h"
|
||||
|
||||
// 实现FMyVertexFactoryParameters, 注意在shader的名字是MyVF.
|
||||
IMPLEMENT_GLOBAL_SHADER_PARAMETER_STRUCT(FMyVertexFactoryParameters, "MyVF");
|
||||
|
||||
// 顶点工厂着色器参数.
|
||||
class FMyVertexFactoryShaderParameters : public FVertexFactoryShaderParameters
|
||||
{
|
||||
DECLARE_TYPE_LAYOUT(FMyVertexFactoryShaderParameters, NonVirtual);
|
||||
|
||||
public:
|
||||
|
||||
void Bind(const FShaderParameterMap& ParameterMap)
|
||||
{
|
||||
}
|
||||
|
||||
void GetElementShaderBindings(
|
||||
const class FSceneInterface* Scene,
|
||||
const class FSceneView* View,
|
||||
const class FMeshMaterialShader* Shader,
|
||||
const EVertexInputStreamType InputStreamType,
|
||||
ERHIFeatureLevel::Type FeatureLevel,
|
||||
const class FVertexFactory* InVertexFactory,
|
||||
const struct FMeshBatchElement& BatchElement,
|
||||
class FMeshDrawSingleShaderBindings& ShaderBindings,
|
||||
FVertexInputStreamArray& VertexStreams) const
|
||||
{
|
||||
// 强制转换成FMyVertexFactory.
|
||||
FMyVertexFactory* VertexFactory = (FMyVertexFactory*)InVertexFactory;
|
||||
|
||||
// 增加shader帮定到表格.
|
||||
ShaderBindings.Add(Shader->GetUniformBufferParameter<FMyVertexFactoryShaderParameters>(), VertexFactory->GetMyVertexFactoryUniformBuffer());
|
||||
|
||||
// 填充顶点流.
|
||||
if (VertexStreams.Num() > 0)
|
||||
{
|
||||
// 处理顶点流索引.
|
||||
for (int32 i = 0; i < 2; ++i)
|
||||
{
|
||||
FVertexInputStream* InstanceInputStream = VertexStreams.FindByPredicate([i](const FVertexInputStream& InStream) { return InStream.StreamIndex == i+1; });
|
||||
// 绑定顶点流索引.
|
||||
InstanceInputStream->VertexBuffer = InstanceDataBuffers->GetBuffer(i);
|
||||
}
|
||||
|
||||
// 处理偏移.
|
||||
if (InstanceOffsetValue > 0)
|
||||
{
|
||||
VertexFactory->OffsetInstanceStreams(InstanceOffsetValue, InputStreamType, VertexStreams);
|
||||
}
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
// ----------- 实现顶点工厂 -----------
|
||||
FMyVertexFactory::FMyVertexFactory(ERHIFeatureLevel::Type InFeatureLevel)
|
||||
{
|
||||
VertexBuffer = new FMyMeshVertexBuffer(16);
|
||||
IndexBuffer = new FMyMeshIndexBuffer(16);
|
||||
}
|
||||
|
||||
FMyVertexFactory::~FMyVertexFactory()
|
||||
{
|
||||
delete VertexBuffer;
|
||||
delete IndexBuffer;
|
||||
}
|
||||
|
||||
void FMyVertexFactory::InitRHI()
|
||||
{
|
||||
Super::InitRHI();
|
||||
|
||||
// 设置Uniform数据.
|
||||
SetupUniformData();
|
||||
|
||||
VertexBuffer->InitResource();
|
||||
IndexBuffer->InitResource();
|
||||
|
||||
// 顶点流: 位置
|
||||
FVertexStream PositionVertexStream;
|
||||
PositionVertexStream.VertexBuffer = VertexBuffer;
|
||||
PositionVertexStream.Stride = sizeof(FVector4);
|
||||
PositionVertexStream.Offset = 0;
|
||||
PositionVertexStream.VertexStreamUsage = EVertexStreamUsage::Default;
|
||||
|
||||
// 简单的实例化顶点流数据 其中VertexBuffer在绑定时设置.
|
||||
FVertexStream InstanceDataVertexStream;
|
||||
InstanceDataVertexStream.VertexBuffer = nullptr;
|
||||
InstanceDataVertexStream.Stride = sizeof(FVector4);
|
||||
InstanceDataVertexStream.Offset = 0;
|
||||
InstanceDataVertexStream.VertexStreamUsage = EVertexStreamUsage::Instancing;
|
||||
|
||||
FVertexElement VertexPositionElement(Streams.Add(PositionVertexStream), 0, VET_Float4, 0, PositionVertexStream.Stride, false);
|
||||
|
||||
// 顶点声明.
|
||||
FVertexDeclarationElementList Elements;
|
||||
Elements.Add(VertexPositionElement);
|
||||
|
||||
// 添加索引顶点流.
|
||||
for (int32 StreamIdx = 0; StreamIdx < NumAdditionalVertexStreams; ++StreamIdx)
|
||||
{
|
||||
FVertexElement InstanceElement(Streams.Add(InstanceDataVertexStream), 0, VET_Float4, 8 + StreamIdx, InstanceDataVertexStream.Stride, true);
|
||||
Elements.Add(InstanceElement);
|
||||
}
|
||||
|
||||
// 初始化声明.
|
||||
InitDeclaration(Elements);
|
||||
}
|
||||
|
||||
void FMyVertexFactory::ReleaseRHI()
|
||||
{
|
||||
UniformBuffer.SafeRelease();
|
||||
|
||||
if (VertexBuffer)
|
||||
{
|
||||
VertexBuffer->ReleaseResource();
|
||||
}
|
||||
|
||||
if (IndexBuffer)
|
||||
{
|
||||
IndexBuffer->ReleaseResource();
|
||||
}
|
||||
|
||||
Super::ReleaseRHI();
|
||||
}
|
||||
|
||||
void FMyVertexFactory::SetupUniformData()
|
||||
{
|
||||
FMyVertexFactoryParameters UniformParams;
|
||||
UniformParams.Color = FVector4(1,0,0,1);
|
||||
|
||||
UniformBuffer = FMyVertexFactoryBufferRef::CreateUniformBufferImmediate(UniformParams, UniformBuffer_MultiFrame);
|
||||
}
|
||||
|
||||
void FMyVertexFactory::ShouldCompilePermutation(const FVertexFactoryShaderPermutationParameters& Parameters)
|
||||
{
|
||||
return true;
|
||||
}
|
||||
|
||||
void FMyVertexFactory::ModifyCompilationEnvironment(const FVertexFactoryShaderPermutationParameters& Parameters, FShaderCompilerEnvironment& OutEnvironment)
|
||||
{
|
||||
OutEnvironment.SetDefine(TEXT("MY_MESH_FACTORY"), 1);
|
||||
}
|
||||
|
||||
void FMyVertexFactory::ValidateCompiledResult(const FVertexFactoryType* Type, EShaderPlatform Platform, const FShaderParameterMap& ParameterMap, TArray<FString>& OutErrors)
|
||||
{
|
||||
}
|
||||
```
|
||||
C++层的逻辑已经完成，但HLSL层也需要编写对应的代码：
|
||||
```c++
|
||||
#include "/Engine/Private/VertexFactoryCommon.ush"
|
||||
|
||||
// VS插值到PS的结构体。
|
||||
struct FVertexFactoryInterpolantsVSToPS
|
||||
{
|
||||
#if NUM_TEX_COORD_INTERPOLATORS
|
||||
float4 TexCoords[(NUM_TEX_COORD_INTERPOLATORS+1)/2] : TEXCOORD0;
|
||||
#endif
|
||||
|
||||
#if VF_USE_PRIMITIVE_SCENE_DATA
|
||||
nointerpolation uint PrimitiveId : PRIMITIVE_ID;
|
||||
#endif
|
||||
|
||||
#if INSTANCED_STEREO
|
||||
nointerpolation uint EyeIndex : PACKED_EYE_INDEX;
|
||||
#endif
|
||||
};
|
||||
|
||||
struct FVertexFactoryInput
|
||||
{
|
||||
float4 Position : ATTRIBUTE0;
|
||||
|
||||
float4 InstanceData0 : ATTRIBUTE8;
|
||||
float4 InstanceData1 : ATTRIBUTE9;
|
||||
|
||||
#if VF_USE_PRIMITIVE_SCENE_DATA
|
||||
uint PrimitiveId : ATTRIBUTE13;
|
||||
#endif
|
||||
};
|
||||
|
||||
struct FPositionOnlyVertexFactoryInput
|
||||
{
|
||||
float4 Position : ATTRIBUTE0;
|
||||
|
||||
float4 InstanceData0 : ATTRIBUTE8;
|
||||
float4 InstanceData1 : ATTRIBUTE9;
|
||||
|
||||
#if VF_USE_PRIMITIVE_SCENE_DATA
|
||||
uint PrimitiveId : ATTRIBUTE1;
|
||||
#endif
|
||||
};
|
||||
|
||||
struct FPositionAndNormalOnlyVertexFactoryInput
|
||||
{
|
||||
float4 Position : ATTRIBUTE0;
|
||||
float4 Normal : ATTRIBUTE2;
|
||||
|
||||
float4 InstanceData0 : ATTRIBUTE8;
|
||||
float4 InstanceData1 : ATTRIBUTE9;
|
||||
|
||||
#if VF_USE_PRIMITIVE_SCENE_DATA
|
||||
uint PrimitiveId : ATTRIBUTE1;
|
||||
#endif
|
||||
};
|
||||
|
||||
struct FVertexFactoryIntermediates
|
||||
{
|
||||
float3 OriginalWorldPos;
|
||||
|
||||
uint PrimitiveId;
|
||||
};
|
||||
|
||||
uint GetPrimitiveId(FVertexFactoryInterpolantsVSToPS Interpolants)
|
||||
{
|
||||
#if VF_USE_PRIMITIVE_SCENE_DATA
|
||||
return Interpolants.PrimitiveId;
|
||||
#else
|
||||
return 0;
|
||||
#endif
|
||||
}
|
||||
|
||||
void SetPrimitiveId(inout FVertexFactoryInterpolantsVSToPS Interpolants, uint PrimitiveId)
|
||||
{
|
||||
#if VF_USE_PRIMITIVE_SCENE_DATA
|
||||
Interpolants.PrimitiveId = PrimitiveId;
|
||||
#endif
|
||||
}
|
||||
|
||||
#if NUM_TEX_COORD_INTERPOLATORS
|
||||
float2 GetUV(FVertexFactoryInterpolantsVSToPS Interpolants, int UVIndex)
|
||||
{
|
||||
float4 UVVector = Interpolants.TexCoords[UVIndex / 2];
|
||||
return UVIndex % 2 ? UVVector.zw : UVVector.xy;
|
||||
}
|
||||
|
||||
void SetUV(inout FVertexFactoryInterpolantsVSToPS Interpolants, int UVIndex, float2 InValue)
|
||||
{
|
||||
FLATTEN
|
||||
if (UVIndex % 2)
|
||||
{
|
||||
Interpolants.TexCoords[UVIndex / 2].zw = InValue;
|
||||
}
|
||||
else
|
||||
{
|
||||
Interpolants.TexCoords[UVIndex / 2].xy = InValue;
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
FMaterialPixelParameters GetMaterialPixelParameters(FVertexFactoryInterpolantsVSToPS Interpolants, float4 SvPosition)
|
||||
{
|
||||
// GetMaterialPixelParameters is responsible for fully initializing the result
|
||||
FMaterialPixelParameters Result = MakeInitializedMaterialPixelParameters();
|
||||
|
||||
#if NUM_TEX_COORD_INTERPOLATORS
|
||||
UNROLL
|
||||
for (int CoordinateIndex = 0; CoordinateIndex < NUM_TEX_COORD_INTERPOLATORS; CoordinateIndex++)
|
||||
{
|
||||
Result.TexCoords[CoordinateIndex] = GetUV(Interpolants, CoordinateIndex);
|
||||
}
|
||||
#endif //NUM_MATERIAL_TEXCOORDS
|
||||
|
||||
Result.TwoSidedSign = 1;
|
||||
Result.PrimitiveId = GetPrimitiveId(Interpolants);
|
||||
|
||||
return Result;
|
||||
}
|
||||
|
||||
FMaterialVertexParameters GetMaterialVertexParameters(FVertexFactoryInput Input, FVertexFactoryIntermediates Intermediates, float3 WorldPosition, half3x3 TangentToLocal)
|
||||
{
|
||||
FMaterialVertexParameters Result = (FMaterialVertexParameters)0;
|
||||
|
||||
Result.WorldPosition = WorldPosition;
|
||||
Result.TangentToWorld = float3x3(1,0,0,0,1,0,0,0,1);
|
||||
Result.PreSkinnedPosition = Input.Position.xyz;
|
||||
Result.PreSkinnedNormal = float3(0,0,1);
|
||||
|
||||
#if NUM_MATERIAL_TEXCOORDS_VERTEX
|
||||
UNROLL
|
||||
for(int CoordinateIndex = 0; CoordinateIndex < NUM_MATERIAL_TEXCOORDS_VERTEX; CoordinateIndex++)
|
||||
{
|
||||
Result.TexCoords[CoordinateIndex] = Intermediates.MorphedWorldPosRaw.xy;
|
||||
}
|
||||
#endif //NUM_MATERIAL_TEXCOORDS_VERTEX
|
||||
|
||||
return Result;
|
||||
}
|
||||
|
||||
FVertexFactoryIntermediates GetVertexFactoryIntermediates(FVertexFactoryInput Input)
|
||||
{
|
||||
FVertexFactoryIntermediates Intermediates;
|
||||
|
||||
// Get the packed instance data
|
||||
float4 Data0 = Input.InstanceData0;
|
||||
float4 Data1 = Input.InstanceData1;
|
||||
|
||||
const float3 Translation = Data0.xyz;
|
||||
const float3 Scale = float3(Data1.zw, 1.0f);
|
||||
const uint PackedDataChannel = asuint(Data1.x);
|
||||
|
||||
// Lod level is in first 8 bits and ShouldMorph bit is in the 9th bit
|
||||
const float LODLevel = (float)(PackedDataChannel & 0xFF);
|
||||
const uint ShouldMorph = ((PackedDataChannel >> 8) & 0x1);
|
||||
|
||||
// Calculate the world pos
|
||||
Intermediates.OriginalWorldPos = float3(Input.Position.xy, 0.0f) * Scale + Translation;
|
||||
|
||||
#if VF_USE_PRIMITIVE_SCENE_DATA
|
||||
Intermediates.PrimitiveId = Input.PrimitiveId;
|
||||
#else
|
||||
Intermediates.PrimitiveId = 0;
|
||||
#endif
|
||||
|
||||
return Intermediates;
|
||||
}
|
||||
|
||||
half3x3 VertexFactoryGetTangentToLocal(FVertexFactoryInput Input, FVertexFactoryIntermediates Intermediates)
|
||||
{
|
||||
return half3x3(1,0,0,0,1,0,0,0,1);
|
||||
}
|
||||
|
||||
float4 VertexFactoryGetRasterizedWorldPosition(FVertexFactoryInput Input, FVertexFactoryIntermediates Intermediates, float4 InWorldPosition)
|
||||
{
|
||||
return InWorldPosition;
|
||||
}
|
||||
|
||||
float3 VertexFactoryGetPositionForVertexLighting(FVertexFactoryInput Input, FVertexFactoryIntermediates Intermediates, float3 TranslatedWorldPosition)
|
||||
{
|
||||
return TranslatedWorldPosition;
|
||||
}
|
||||
|
||||
FVertexFactoryInterpolantsVSToPS VertexFactoryGetInterpolantsVSToPS(FVertexFactoryInput Input, FVertexFactoryIntermediates Intermediates, FMaterialVertexParameters VertexParameters)
|
||||
{
|
||||
FVertexFactoryInterpolantsVSToPS Interpolants;
|
||||
|
||||
Interpolants = (FVertexFactoryInterpolantsVSToPS)0;
|
||||
|
||||
#if NUM_TEX_COORD_INTERPOLATORS
|
||||
float2 CustomizedUVs[NUM_TEX_COORD_INTERPOLATORS];
|
||||
GetMaterialCustomizedUVs(VertexParameters, CustomizedUVs);
|
||||
GetCustomInterpolators(VertexParameters, CustomizedUVs);
|
||||
|
||||
UNROLL
|
||||
for (int CoordinateIndex = 0; CoordinateIndex < NUM_TEX_COORD_INTERPOLATORS; CoordinateIndex++)
|
||||
{
|
||||
SetUV(Interpolants, CoordinateIndex, CustomizedUVs[CoordinateIndex]);
|
||||
}
|
||||
#endif
|
||||
|
||||
#if INSTANCED_STEREO
|
||||
Interpolants.EyeIndex = 0;
|
||||
#endif
|
||||
|
||||
SetPrimitiveId(Interpolants, Intermediates.PrimitiveId);
|
||||
|
||||
return Interpolants;
|
||||
}
|
||||
|
||||
float4 VertexFactoryGetWorldPosition(FPositionOnlyVertexFactoryInput Input)
|
||||
{
|
||||
return Input.Position;
|
||||
}
|
||||
|
||||
float4 VertexFactoryGetPreviousWorldPosition(FVertexFactoryInput Input, FVertexFactoryIntermediates Intermediates)
|
||||
{
|
||||
float4x4 PreviousLocalToWorldTranslated = GetPrimitiveData(Intermediates.PrimitiveId).PreviousLocalToWorld;
|
||||
PreviousLocalToWorldTranslated[3][0] += ResolvedView.PrevPreViewTranslation.x;
|
||||
PreviousLocalToWorldTranslated[3][1] += ResolvedView.PrevPreViewTranslation.y;
|
||||
PreviousLocalToWorldTranslated[3][2] += ResolvedView.PrevPreViewTranslation.z;
|
||||
|
||||
return mul(Input.Position, PreviousLocalToWorldTranslated);
|
||||
}
|
||||
|
||||
float4 VertexFactoryGetTranslatedPrimitiveVolumeBounds(FVertexFactoryInterpolantsVSToPS Interpolants)
|
||||
{
|
||||
float4 ObjectWorldPositionAndRadius = GetPrimitiveData(GetPrimitiveId(Interpolants)).ObjectWorldPositionAndRadius;
|
||||
return float4(ObjectWorldPositionAndRadius.xyz + ResolvedView.PreViewTranslation.xyz, ObjectWorldPositionAndRadius.w);
|
||||
}
|
||||
|
||||
uint VertexFactoryGetPrimitiveId(FVertexFactoryInterpolantsVSToPS Interpolants)
|
||||
{
|
||||
return GetPrimitiveId(Interpolants);
|
||||
}
|
||||
|
||||
float3 VertexFactoryGetWorldNormal(FPositionAndNormalOnlyVertexFactoryInput Input)
|
||||
{
|
||||
return Input.Normal.xyz;
|
||||
}
|
||||
|
||||
float3 VertexFactoryGetWorldNormal(FVertexFactoryInput Input, FVertexFactoryIntermediates Intermediates)
|
||||
{
|
||||
return float3(0.0f, 0.0f, 1.0f);
|
||||
}
|
||||
```
|
||||
|
||||
由此可见，如果新增加了FVertexFactory的自定义类型，需要在HLSL实现以下接口：
|
||||
- FVertexFactoryInput 定义输入到VS的数据布局，需要匹配c++侧的FVertexFactory的类型。
|
||||
- FVertexFactoryIntermediates 用于存储将在多个顶点工厂函数中使用的缓存中间数据，比如TangentToLocal。
|
||||
- FVertexFactoryInterpolantsVSToPS 从VS传递到PS的顶点工厂数据。
|
||||
- VertexFactoryGetWorldPosition 从顶点着色器调用来获得世界空间的顶点位置。
|
||||
- VertexFactoryGetInterpolantsVSToPS 转换FVertexFactoryInput到FVertexFactoryInterpolants，在硬件光栅化插值之前计算需要插值或传递到PS的数据。
|
||||
- GetMaterialPixelParameters 由PS调用，根据FVertexFactoryInterpolants计算并填充FMaterialPixelParameters结构体。
|
||||
@ -7,3 +7,5 @@ rating: ⭐
|
||||
---
|
||||
# 前言
|
||||
https://www.cnblogs.com/timlly/p/15109132.html
|
||||
|
||||
# UMaterial
|
||||
Loading…
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Reference in New Issue
Block a user