208 lines
		
	
	
		
			9.8 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			208 lines
		
	
	
		
			9.8 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# 参考文章
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- UE4:https://zhuanlan.zhihu.com/p/446587397
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- UE5.2 https://zhuanlan.zhihu.com/p/658700282
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- UE5.1 https://zhuanlan.zhihu.com/p/565837897
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# 备注
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添加的定义:
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- MATERIAL_SHADINGMODEL_TOONSTANDARD
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- SHADINGMODELID_TOONSTANDARD
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- PIXEL_INSPECTOR_SHADINGMODELID_TOONSTANDARD
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添加的功能:
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- Material
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	- 材质编辑器引脚
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	- 相关引脚控制
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	- ShaderModel
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- ViewMode - BufferVisualization
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	- ShaderModel可视化
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	- ToonBuffer可视化
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- PixelInspector
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# c++部分
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## 添加ShaderModel
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- EngineTypes.h 在EMaterialShadingModel中添加ShaderModel枚举
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## 材质宏添加数值
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ShaderMaterial.h给材质宏`MATERIAL_SHADINGMODEL_TOONSTANDARD`添加数值。
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```c++
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uint8 MATERIAL_SHADINGMODEL_TOONSTANDARD : 1;
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```
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之后再ShaderGenerationUtil.cpp的ApplyFetchEnvironment()与DetermineUsedMaterialSlots()添加对应代码。
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## 添加材质编辑器引脚
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- SceneTypes.h 在EMaterialProperty中添加2个引脚属性名称枚举。
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- Material.h 在UMaterial类中添加FScalarMaterialInput类型变量CustomData2与CustomData3。
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### MaterialExpressions.cpp
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- 给MakeMaterialAttributes节点增加对应引脚:
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    - 添加CustomData2与CustomData3声明。(位于MaterialExpressionMakeMaterialAttributes.h)
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    - 修改UMaterialExpressionMakeMaterialAttributes::Compile(),增加CustomData2与CustomData3的对应列。
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- 给BreakMaterialAttributes节点增加对应引脚:
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    - 修改UMaterialExpressionBreakMaterialAttributes::UMaterialExpressionBreakMaterialAttributes(),增加CustomData2与CustomData3的对应列。
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    - 修改UMaterialExpressionBreakMaterialAttributes::Serialize(),增加两列`Outputs[OutputIndex].SetMask(1, 1, 0, 0, 0); ++OutputIndex;`
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- 修改BuildPropertyToIOIndexMap(),增加CustomData2与CustomData3的对应列,并且将最后一行的index改成合适的数值。
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- 修改断言条件`static_assert(MP_MAX == 32`=>`static_assert(MP_MAX == 34`
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### MaterialShared.cpp
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- 修改FMaterialAttributeDefinitionMap::InitializeAttributeMap(),给CustomData2与CustomData3添加对应码,只需与之前的不重复即可。
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- 修改FMaterialAttributeDefinitionMap::GetAttributeOverrideForMaterial(),修改新添加的ShaderModel的引脚在材质编辑器中的显示名称。
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### MaterialShader.cpp
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- 修改GetShadingModelString(),给新增加的ShaderModel添加返回字符串。
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- 修改UpdateMaterialShaderCompilingStats(),给性能统计添加新增加的ShaderModel条件判断,`else if (ShadingModels.HasAnyShadingModel({ MSM_DefaultLit, MSM_Subsurface, MSM_PreintegratedSkin, MSM_ClearCoat, MSM_Cloth, MSM_SubsurfaceProfile, MSM_TwoSidedFoliage, MSM_SingleLayerWater, MSM_ThinTranslucent ,MSM_NPRShading}))`
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### Material.cpp
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- 修改UMaterial::PostLoad(),给新增加的引脚添加对应的两行代码,来对材质属性进行重新排序,`DoMaterialAttributeReorder(&CustomData2, UE4Ver, RenderObjVer);`
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- 修改UMaterial::GetExpressionInputForProperty(),给新增加的引脚添加对应的两行代码。
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- 修改UMaterial::CompilePropertyEx(),给新增加的引脚添加对应的两行代码。编译材质属性。
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- 修改static bool IsPropertyActive_Internal(),控制材质编辑器中引脚是否开启。给CustomData添加对应的代码。
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### HLSLMaterialTranslator.cpp
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控制材质节点编译(拼接)成完整的ShaderCode。
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- 修改FHLSLMaterialTranslator::FHLSLMaterialTranslator(),给SharedPixelProperties数组中引脚对应index赋值为true。
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- 修改FHLSLMaterialTranslator::GetMaterialEnvironment(),给新增加的ShaderModel添加宏。
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- 修改FHLSLMaterialTranslator::GetMaterialShaderCode()。给新增加的引脚添加对应的两行`LazyPrintf.PushParam(*GenerateFunctionCode(MP_CustomData1));`。该函数会读取`/Engine/Private/MaterialTemplate.ush`并对替换字符格式化。
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- 修改FHLSLMaterialTranslator::Translate(),为新增加的两个引脚增加两行:
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```c#
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Chunk[MP_CustomData2]		= Material->CompilePropertyAndSetMaterialProperty(MP_CustomData2	,this);//NPR Shading
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Chunk[MP_CustomData3]		= Material->CompilePropertyAndSetMaterialProperty(MP_CustomData3	,this);
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```
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### MaterialGraph.cpp
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材质界面代码。修改UMaterialGraph::RebuildGraph(),用来显示新添加的两个引脚:
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```c#
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MaterialInputs.Add( FMaterialInputInfo(FMaterialAttributeDefinitionMap::GetDisplayNameForMaterial(MP_CustomData2, Material), MP_CustomData2, FMaterialAttributeDefinitionMap::GetDisplayNameForMaterial(MP_CustomData2, Material)));
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MaterialInputs.Add( FMaterialInputInfo(FMaterialAttributeDefinitionMap::GetDisplayNameForMaterial(MP_CustomData3, Material), MP_CustomData3, FMaterialAttributeDefinitionMap::GetDisplayNameForMaterial(MP_CustomData3, Material)));
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```
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### 解决添加引脚后
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添加引脚后会出现`PropertyConnectedBitmask cannot contain entire EMaterialProperty enumeration.`的编译错误。需要将
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```c#
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uint32 PropertyConnectedBitmask;
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```
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=》
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```c#
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uint64 PropertyConnectedBitmask;
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```
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再将函数中的转换类型改成uint64即可。
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```c#
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ENGINE_API bool IsConnected(EMaterialProperty Property) { return ((PropertyConnectedBitmask >> (uint64)Property) & 0x1) != 0; }
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ENGINE_API void SetConnectedProperty(EMaterialProperty Property, bool bIsConnected) 
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{
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    PropertyConnectedBitmask = bIsConnected ? PropertyConnectedBitmask | (1i64 << (uint64)Property) : PropertyConnectedBitmask & ~(1i64 << (uint64)Property);
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}
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```
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## 控制引脚
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### Material.cpp(控制引脚开启)
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在IsPropertyActive_Internal()中修改:
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```c++
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case MP_CustomData0:  
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    Active = ShadingModels.HasAnyShadingModel({ MSM_ClearCoat, MSM_Hair, MSM_Cloth, MSM_Eye, MSM_SubsurfaceProfile, MSM_ToonStandard, MSM_PreintegratedSkin });  
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    break;  
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case MP_CustomData1:  
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    Active = ShadingModels.HasAnyShadingModel({ MSM_ClearCoat, MSM_Eye, MSM_ToonStandard, MSM_PreintegratedSkin });  
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    break;
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```
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### MaterialShared.cpp(修改引脚显示名称)
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在MaterialShared.cpp的GetAttributeOverrideForMaterial()中修改:
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```c++
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case MP_CustomData0:  
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    CustomPinNames.Add({ MSM_ClearCoat, "Clear Coat" });  
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    CustomPinNames.Add({ MSM_Hair, "Backlit" });  
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    CustomPinNames.Add({ MSM_Cloth, "Cloth" });  
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    CustomPinNames.Add({ MSM_Eye, "Iris Mask" });  
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    CustomPinNames.Add({ MSM_SubsurfaceProfile, "Curvature" });  
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    CustomPinNames.Add({ MSM_ToonStandard, "ToonDataA" });  
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    CustomPinNames.Add({ MSM_PreintegratedSkin, "ToonDataA" });  
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    return FText::FromString(GetPinNameFromShadingModelField(Material->GetShadingModels(), CustomPinNames, "Custom Data 0"));  
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case MP_CustomData1:  
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    CustomPinNames.Add({ MSM_ClearCoat, "Clear Coat Roughness" });  
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    CustomPinNames.Add({ MSM_Eye, "Iris Distance" });  
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    CustomPinNames.Add({ MSM_ToonStandard, "ToonDataB" });  
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    CustomPinNames.Add({ MSM_PreintegratedSkin, "ToonDataB" });  
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    return FText::FromString(GetPinNameFromShadingModelField(Material->GetShadingModels(), CustomPinNames, "Custom Data 1"));
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```
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### ShaderMaterialDerivedHelpers.cpp(CustomData数据传递)
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在CalculateDerivedMaterialParameters()中修改代码,让CustomData渲染到GBuffer上:
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```c++
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// Only some shader models actually need custom data.  
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Dst.WRITES_CUSTOMDATA_TO_GBUFFER = (Dst.USES_GBUFFER && (Mat.MATERIAL_SHADINGMODEL_SUBSURFACE || Mat.MATERIAL_SHADINGMODEL_PREINTEGRATED_SKIN || Mat.MATERIAL_SHADINGMODEL_SUBSURFACE_PROFILE || Mat.MATERIAL_SHADINGMODEL_CLEAR_COAT || Mat.MATERIAL_SHADINGMODEL_TWOSIDED_FOLIAGE || Mat.MATERIAL_SHADINGMODEL_HAIR || Mat.MATERIAL_SHADINGMODEL_CLOTH || Mat.MATERIAL_SHADINGMODEL_EYE));
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```
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## PixelInspectorResult
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在PixelInspectorResult.h中添加`PIXEL_INSPECTOR_SHADINGMODELID_TOONSTANDARD`宏定义。
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之后在PixelInspectorResult.cpp的DecodeShadingModel()函数中添加定义。
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### PixelInspectorDetailsCustomization(修改菜单显示屏蔽属性用)
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# Shader部分
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## MaterialTemplate.ush
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给新增加的引脚增加对应的格式化代码:
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```c#
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half GetMaterialCustomData2(FMaterialPixelParameters Parameters)
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{
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%s;
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}
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half GetMaterialCustomData3(FMaterialPixelParameters Parameters)
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{
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%s;
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}
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```
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## ShadingCommon.ush
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- 新增加的ShaderModel添加ID宏,`#define SHADINGMODELID_NPRSHADING			12`
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- 修改float3 GetShadingModelColor(uint ShadingModelID),给添加的ShaderModel设置一个显示颜色。
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## Definitions.ush(定义材质宏)
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位于`Engine\Shaders\Private\Definitions.ush`。
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## BasePassCommon.ush
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- ~~修改#define WRITES_CUSTOMDATA_TO_GBUFFER宏,在最后的条件判断中添加新增加的ShaderModel~~。**UE5.1将该逻辑转移到C++中**
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## DeferredShadingCommon.ush
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- 修改bool HasCustomGBufferData(int ShadingModelID),在条件判断中添加新增加的ShaderModel。
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## ShadingModelsMaterial.ush
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- 修改void SetGBufferForShadingModel(),该函数用于设置输出的GBuffer,给新增加的ShaderModel添加对应的代码段:
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```c#
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#ifdef MATERIAL_SHADINGMODEL_NPRSHADING
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else if(ShadingModel == SHADINGMODELID_NPRSHADING)
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{
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  GBuffer.CustomData.x=saturate(GetMaterialCustomData0(MaterialParameters));
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  GBuffer.CustomData.y=saturate(GetMaterialCustomData1(MaterialParameters));
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  GBuffer.CustomData.z=saturate(GetMaterialCustomData2(MaterialParameters));
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  GBuffer.CustomData.w=saturate(GetMaterialCustomData3(MaterialParameters));
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}
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#endif
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```
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## 光照实现
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- ShadingModel.ush,BxDF实现。
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- DeferredLightingCommon.ush,延迟光照实现。
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# 相关文件
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- UMaterialInterface、UMaterial、UMaterialInstance、FMaterial、FMaterialResource、FMateialRenderProxy、FMaterialInstanceResource、FDefaultMaterialInstance
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- MaterialShader.cpp
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- HLSLMaterialTranslator.cpp
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- MaterialHLSLEmitter:塞入ShaderModel宏
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- Material.cpp:开启引脚
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- MaterialAttributeDefinitionMap.cpp
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- ShaderMaterialDerivedHelpers.cpp
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- ShaderGenerationUtil.cpp
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- ShadingCommon.ush
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# Material编辑器相关代码
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- FMaterialInstanceBasePropertyOverrides
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- FMaterialInstanceParameterDetails
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https://zhuanlan.zhihu.com/p/565776677
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https://www.cnblogs.com/timlly/p/15109132.html |