BlueRoseNote/03-UnrealEngine/Rendering/RenderFeature/ShaderWorldPlugin/ShaderWorld.md

---
title: Untitled
date: 2025-06-03 10:19:25
excerpt: 
tags: 
rating: ⭐
---
# 前言
1. ShaderWorldPCGInterop：
2. ShaderWorld：
3. ShaderWorldCore：

# ShaderWorld
- Class 
	- Actor
		- ShaderWorldActor.h:[[#AShaderWorldActor]]
		- SWorld.h:[[#ASWorld]]

## ASWorld
## AShaderWorldActor



## DrawMaterialToRenderTarget
USWorldSubsystem::DrawMaterialToRenderTarget
=>
SWShaderToolBox::DrawMaterial
=>
DrawMaterial_CS_RT

调用路径：
- AShaderWorldActor::RetrieveHeightAt（好像没有引用）：检索高度
- AShaderWorldActor::ComputeHeight_Segmented_MapForClipMap
	- AShaderWorldActor::ProcessSegmentedComputation() <- AShaderWorldActor::TerrainAndSpawnablesManagement() <- AShaderWorldActor::Tick()
- AShaderWorldActor::ComputeHeightMapForClipMap
	- AShaderWorldActor::UpdateClipMap() <- AShaderWorldActor::TerrainAndSpawnablesManagement() <- AShaderWorldActor::Tick()
- AShaderWorldActor::ComputeDataLayersForClipMap
	- AShaderWorldActor::UpdateClipMap() <- AShaderWorldActor::TerrainAndSpawnablesManagement() <- AShaderWorldActor::Tick()
- AShaderWorldActor::UpdateCollisionMeshData：更新碰撞模型数据。
	- AShaderWorldActor::CollisionGPU() <- AShaderWorldActor::CollisionManagement() <- AShaderWorldActor::Tick()
- FSpawnableMesh::UpdateSpawnableData
	- AShaderWorldActor::ProcessSegmentedComputation() <- AShaderWorldActor::TerrainAndSpawnablesManagement() <- AShaderWorldActor::Tick()


## Cache机制
AShaderWorldActor::ProcessSegmentedComputation() <- AShaderWorldActor::TerrainAndSpawnablesManagement() <- AShaderWorldActor::Tick()


# 其他Bug
CacheMatDyn？
MatDyn？

## SetTextureParameterValue相关逻辑排查
- AShaderWorldActor中的SetTextureParameterValue
	- ~~ExportCacheInBounds~~
	- ~~AssignHeightMapToDynamicMaterial~~
	- UpdateStaticDataFor
	- ComputeHeight_Segmented_MapForClipMap：似乎会设置
	- UpdateCollisionMeshData
	- [x] [[#InitializeReadBackDependencies]]
	- [x] InitiateMaterials


### UpdateCollisionMeshData
 Tick() -> CollisionManagement() -> CollisionGPU() -> UpdateCollisionMeshData()

### ComputeHeight_Segmented_MapForClipMap




### InitializeReadBackDependencies
BeginPlay() -> InitiateWorld() -> InitializeReadBackDependencies()

1. 初始化3个RT：ReadRequestLocation、ReadRequestLocationHeightmap、GeneratorDynamicForReadBack。
2. 会设置`TObjectPtr < UMaterialInstanceDynamic> GeneratorDynamicForReadBack`各种变量
```c++
GeneratorDynamicForReadBack->SetScalarParameterValue("HeightReadBack", 1.f);  
GeneratorDynamicForReadBack->SetTextureParameterValue("SpecificLocationsRT", ReadRequestLocation);  
GeneratorDynamicForReadBack->SetScalarParameterValue("NoMargin", 0.f);  
GeneratorDynamicForReadBack->SetScalarParameterValue("N", N);  
GeneratorDynamicForReadBack->SetScalarParameterValue("NormalMapSelect", 0.f);  
GeneratorDynamicForReadBack->SetScalarParameterValue("HeightMapToggle", 1.f);
```
3. 设置随机种子相关Shader Parameter。
### InitiateMaterials
作用：初始化`TArray<FClipMapMeshElement> Meshes;`的Material、`Producers`
调用顺序：BeginPlay() -> InitiateWorld() -> InitiateMaterials()

经过断点调试，会设置WorldSettings里的Material（地形Material）的HeightMap与NormalMap。