486 lines
21 KiB
Markdown
486 lines
21 KiB
Markdown
---
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title: GBuffer&Material&BasePass
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date: 2023-12-08 17:34:58
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excerpt:
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tags:
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rating: ⭐
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---
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# # GBuffer
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目前UE5.3会调用
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- WriteGBufferInfoAutogen()
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- **EncodeGBufferToMRT()**
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动态生成BasePassPixelShader.usf中的**EncodeGBufferToMRT()** 的代码，并且会生成一个AutogenShaderHeaders.ush文件。其路径为：
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`Engine\Intermediate\ShaderAutogen\PCD3D_SM5`或者`Engine\Intermediate\ShaderAutogen\PCD3D_ES3_1`
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1. ***给FGBufferData添加结构体数据时需要在此添加额外代码逻辑***
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2. GBuffer精度在FetchLegacyGBufferInfo()设置。
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3. 是否往GBuffer中写入Velocity，主要靠这个宏**WRITES_VELOCITY_TO_GBUFFER**。具体决定其数值的逻辑位于**FShaderGlobalDefines FetchShaderGlobalDefines**。主要还是靠**r.VelocityOutputPass**进行开启。
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1. PS. MSAA以及VR绝对不会开启Velocity输出选项。还有就是**r.Velocity.ForceOutput**，但经过测试不开启r.VelocityOutputPass依然无法输出。以及FPrimitiveSceneProxy的bAlwaysHasVelocity与bHasWorldPositionOffsetVelocity。
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2. 其他相关FSR、TSR？
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4. 如何添加GBuffer
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1. https://zhuanlan.zhihu.com/p/568775542
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2. https://zhuanlan.zhihu.com/p/677772284
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## UE5 GBuffer内容：
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[[UE GBuffer存储数据]]
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```c#
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OutGBufferA(MRT1) = WorldNormal/PerObjectGBufferData (GBT_Float_16_16_16_16/GBT_Unorm_11_11_10/GBT_Unorm_8_8_8_8)
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OutGBufferB(MRT2) = Metallic/Specular/Roughness/EncodeShadingModelIdAndSelectiveOutputMask (GBT_Float_16_16_16_16/GBT_Unorm_8_8_8_8)
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OutGBufferC(MRT3) = BaseColor/GBufferAO (GBT_Unorm_8_8_8_8)
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OutGBufferD = GBuffer.CustomData (GBT_Unorm_8_8_8_8)
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OutGBufferE = GBuffer.PrecomputedShadowFactors (GBT_Unorm_8_8_8_8)
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TargetVelocity / OutGBufferF = velocity / tangent (默认不开启 带有深度<开启Lumen与距离场 或者 开启光线追踪> GBC_Raw_Float_16_16_16_16 不带深度 GBC_Raw_Float_16_16)
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TargetSeparatedMainDirLight = SingleLayerWater相关 (有SingleLayerWater才会开启 GBC_Raw_Float_11_11_10)
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// 0..1, 2 bits, use CastContactShadow(GBuffer) or HasDynamicIndirectShadowCasterRepresentation(GBuffer) to extract
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half PerObjectGBufferData;
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```
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GBuffer相关信息（精度、顺序）可以参考FetchLegacyGBufferInfo()。
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- 不存在Velocity与Tangent:
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- OutGBufferD(MRT4)
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- OutGBufferD(MRT5)
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- TargetSeparatedMainDirLight(MRT6)
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- 存在Velocity：
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- TargetVelocity(MRT4)
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- OutGBufferD(MRT5)
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- OutGBufferE(MRT6)
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- TargetSeparatedMainDirLight(MRT7)
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- 存在Tangent：
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- OutGBufferF(MRT4)
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- OutGBufferD(MRT5)
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- OutGBufferE(MRT6)
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- TargetSeparatedMainDirLight(MRT7)
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几个动态MRT的存在条件与Shader判断宏：
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- OutGBufferE(PrecomputedShadowFactors)：r.AllowStaticLighting = 1
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- GBUFFER_HAS_PRECSHADOWFACTOR
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- WRITES_PRECSHADOWFACTOR_ZERO
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- WRITES_PRECSHADOWFACTOR_TO_GBUFFER
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- TargetVelocity：(IsUsingBasePassVelocity(Platform) || Layout == GBL_ForceVelocity) ? 1 : 0;//r.VelocityOutputPass = 1
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- r.VelocityOutputPass = 1时，会对骨骼物体以及WPO材质物体输出速度。因为大概率会使用距离场阴影以及VSM，所以会占用GBuffer Velocity所有通道。
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- GBUFFER_HAS_VELOCITY
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- WRITES_VELOCITY_TO_GBUFFER
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- SingleLayerWater
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- 默认不会写入GBuffer需要符合以下条件：const bool bNeedsSeparateMainDirLightTexture = IsWaterDistanceFieldShadowEnabled(Parameters.Platform) || IsWaterVirtualShadowMapFilteringEnabled(Parameters.Platform);
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- r.Water.SingleLayer.ShadersSupportDistanceFieldShadow = 1
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- r.Water.SingleLayer.ShadersSupportVSMFiltering = 1
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- const bool bIsSingleLayerWater = Parameters.MaterialParameters.ShadingModels.HasShadingModel(MSM_SingleLayerWater);
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- Tangent：false，目前单独使用另一组MRT来存储。
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- ~~GBUFFER_HAS_TANGENT~`
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### ToonGBuffer修改&数据存储
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```c#
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OutGBufferA:PerObjectGBufferData => 可以存储额外的有关Tonn渲染功能参数。
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OutGBufferB:Metallic/Specular/Roughness =>
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? / SpcularPower(控制高光亮度与Mask) / ? / ?
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//ToonHairMask OffsetShadowMask/SpcularMask/SpecularValue
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OutGBufferC:GBufferAO =>
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ToonAO
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OutGBufferD:CustomData.xyzw =>
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ShadowColor.rgb / NoLOffset //ShadowColor这里可以在Material里通过主光向量、ShadowStep、Shadow羽化计算多层阴影效果。
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OutGBufferE:GBuffer.PrecomputedShadowFactors.xyzw =>
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ToonDataID/ ToonOutlineDataID / OutlineMask(控制Outline绘制以及Outline强度) / ToonObjectID(判断是否是一个物体)
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TargetVelocity / OutGBufferF = velocity / tangent //目前先不考虑输出Velocity的情况
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? / ? / ? / ?
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```
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ToonDataID在材质编辑器中会存在SubsurfaceColor.a中，ToonOutlineDataID在材质编辑器中会存在CustomData1（引脚名为ToonBufferB，考虑到Subsurface有一个CurvatureMap需要使用CustomData0，所以这里使用了CustomData1）。
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蓝色协议的方案
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![[蓝色协议的方案#GBuffer]]
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***额外添加相关宏（逻辑位于ShaderCompiler.cpp）***
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- **GBUFFER_HAS_TOONDATA**
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### 修改GBuffer格式
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- [[#ShaderMaterialDerivedHelpers.cpp中的CalculateDerivedMaterialParameters()]]控制在BasePassPixelShader.usf中的MRT宏是否为true。
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- [[#BasePassRendering.cpp中ModifyBasePassCSPSCompilationEnvironment()]]控制Velocity与SingleLayerWater相关的RT精度。
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- [[#GBufferInfo.cpp中的FetchLegacyGBufferInfo()]]控制GBuffer精度以及数据打包情况。
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#### BasePassRendering.cpp中ModifyBasePassCSPSCompilationEnvironment()
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```c++
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void ModifyBasePassCSPSCompilationEnvironment()
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{
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...
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const bool bOutputVelocity = (GBufferLayout == GBL_ForceVelocity) ||
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FVelocityRendering::BasePassCanOutputVelocity(Parameters.Platform);
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if (bOutputVelocity)
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{
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// As defined in BasePassPixelShader.usf. Also account for Strata setting velocity in slot 1 as described in FetchLegacyGBufferInfo.
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const int32 VelocityIndex = Strata::IsStrataEnabled() ? 1 : (IsForwardShadingEnabled(Parameters.Platform) ? 1 : 4);
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OutEnvironment.SetRenderTargetOutputFormat(VelocityIndex, PF_G16R16);
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}
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...
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const bool bNeedsSeparateMainDirLightTexture = IsWaterDistanceFieldShadowEnabled(Parameters.Platform) || IsWaterVirtualShadowMapFilteringEnabled(Parameters.Platform);
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if (bIsSingleLayerWater && bNeedsSeparateMainDirLightTexture)
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{
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// See FShaderCompileUtilities::FetchGBufferParamsRuntime for the details
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const bool bHasTangent = false;
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static const auto CVar = IConsoleManager::Get().FindTConsoleVariableDataInt(TEXT("r.AllowStaticLighting"));
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bool bHasPrecShadowFactor = (CVar ? (CVar->GetValueOnAnyThread() != 0) : 1);
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uint32 TargetSeparatedMainDirLight = 5;
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if (bOutputVelocity == false && bHasTangent == false)
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{
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TargetSeparatedMainDirLight = 5;
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if (bHasPrecShadowFactor)
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{
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TargetSeparatedMainDirLight = 6;
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}
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}
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else if (bOutputVelocity)
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{
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TargetSeparatedMainDirLight = 6;
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if (bHasPrecShadowFactor)
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{
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TargetSeparatedMainDirLight = 7;
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}
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}
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else if (bHasTangent)
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{
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TargetSeparatedMainDirLight = 6;
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if (bHasPrecShadowFactor)
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{
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TargetSeparatedMainDirLight = 7;
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}
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}
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OutEnvironment.SetRenderTargetOutputFormat(TargetSeparatedMainDirLight, PF_FloatR11G11B10);
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...
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}
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```
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#### GBufferInfo.cpp中的FetchLegacyGBufferInfo()
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控制GBuffer精度以及数据打包情况。
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#### ShaderMaterialDerivedHelpers.cpp中的CalculateDerivedMaterialParameters()
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```c++
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else if (Mat.IS_BASE_PASS)
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{
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Dst.PIXELSHADEROUTPUT_BASEPASS = 1;
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if (Dst.USES_GBUFFER)
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{
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Dst.PIXELSHADEROUTPUT_MRT0 = (!SrcGlobal.SELECTIVE_BASEPASS_OUTPUTS || Dst.NEEDS_BASEPASS_VERTEX_FOGGING || Mat.USES_EMISSIVE_COLOR || SrcGlobal.ALLOW_STATIC_LIGHTING || Mat.MATERIAL_SHADINGMODEL_SINGLELAYERWATER);
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Dst.PIXELSHADEROUTPUT_MRT1 = ((!SrcGlobal.SELECTIVE_BASEPASS_OUTPUTS || !Mat.MATERIAL_SHADINGMODEL_UNLIT));
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Dst.PIXELSHADEROUTPUT_MRT2 = ((!SrcGlobal.SELECTIVE_BASEPASS_OUTPUTS || !Mat.MATERIAL_SHADINGMODEL_UNLIT));
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Dst.PIXELSHADEROUTPUT_MRT3 = ((!SrcGlobal.SELECTIVE_BASEPASS_OUTPUTS || !Mat.MATERIAL_SHADINGMODEL_UNLIT));
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if (SrcGlobal.GBUFFER_HAS_VELOCITY || SrcGlobal.GBUFFER_HAS_TANGENT)
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{
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Dst.PIXELSHADEROUTPUT_MRT4 = Dst.WRITES_VELOCITY_TO_GBUFFER || SrcGlobal.GBUFFER_HAS_TANGENT;
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Dst.PIXELSHADEROUTPUT_MRT5 = (!SrcGlobal.SELECTIVE_BASEPASS_OUTPUTS || Dst.WRITES_CUSTOMDATA_TO_GBUFFER);
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Dst.PIXELSHADEROUTPUT_MRT6 = (Dst.GBUFFER_HAS_PRECSHADOWFACTOR && (!SrcGlobal.SELECTIVE_BASEPASS_OUTPUTS || (Dst.WRITES_PRECSHADOWFACTOR_TO_GBUFFER && !Mat.MATERIAL_SHADINGMODEL_UNLIT)));
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}
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else
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{
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Dst.PIXELSHADEROUTPUT_MRT4 = (!SrcGlobal.SELECTIVE_BASEPASS_OUTPUTS || Dst.WRITES_CUSTOMDATA_TO_GBUFFER);
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Dst.PIXELSHADEROUTPUT_MRT5 = (Dst.GBUFFER_HAS_PRECSHADOWFACTOR && (!SrcGlobal.SELECTIVE_BASEPASS_OUTPUTS || (Dst.WRITES_PRECSHADOWFACTOR_TO_GBUFFER && !Mat.MATERIAL_SHADINGMODEL_UNLIT)));
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}
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}
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else
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{
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Dst.PIXELSHADEROUTPUT_MRT0 = true;
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// we also need MRT for thin translucency due to dual blending if we are not on the fallback path
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Dst.PIXELSHADEROUTPUT_MRT1 = (Dst.WRITES_VELOCITY_TO_GBUFFER || (Mat.DUAL_SOURCE_COLOR_BLENDING_ENABLED && Dst.MATERIAL_WORKS_WITH_DUAL_SOURCE_COLOR_BLENDING));
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}
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}
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}
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```
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位于FShaderCompileUtilities::ApplyDerivedDefines()，新版本逻辑遍历数据由GBufferInfo.cpp中的FetchLegacyGBufferInfo()处理。
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```c++
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#if 1
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static bool bTestNewVersion = true;
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if (bTestNewVersion)
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{
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//if (DerivedDefines.USES_GBUFFER)
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{
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for (int32 Iter = 0; Iter < FGBufferInfo::MaxTargets; Iter++)
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{
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if (bTargetUsage[Iter])
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{
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FString TargetName = FString::Printf(TEXT("PIXELSHADEROUTPUT_MRT%d"), Iter);
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OutEnvironment.SetDefine(TargetName.GetCharArray().GetData(), TEXT("1"));
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}
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}
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}
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}
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else
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{
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// This uses the legacy logic from CalculateDerivedMaterialParameters(); Just keeping it around momentarily for testing during the transition.
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SET_COMPILE_BOOL_IF_TRUE(PIXELSHADEROUTPUT_MRT0)
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SET_COMPILE_BOOL_IF_TRUE(PIXELSHADEROUTPUT_MRT1)
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SET_COMPILE_BOOL_IF_TRUE(PIXELSHADEROUTPUT_MRT2)
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SET_COMPILE_BOOL_IF_TRUE(PIXELSHADEROUTPUT_MRT3)
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SET_COMPILE_BOOL_IF_TRUE(PIXELSHADEROUTPUT_MRT4)
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SET_COMPILE_BOOL_IF_TRUE(PIXELSHADEROUTPUT_MRT5)
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SET_COMPILE_BOOL_IF_TRUE(PIXELSHADEROUTPUT_MRT6)
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}
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#endif
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```
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### MaterialTemplate.ush
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MaterialTemplate.ush中定义许多模版函数，里面的具体内容会在HLSLMaterialTranslator.h中的**GetMaterialShaderCode()** 中添加。最后这些函数会在BassPassPixelShader.usf中调用。
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bool bEnableExecutionFlow的作用为是否使用新的材质HLSL生成器，默认为0。
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```c++
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static TAutoConsoleVariable<int32> CVarMaterialEnableNewHLSLGenerator(
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TEXT("r.MaterialEnableNewHLSLGenerator"),
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0,
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TEXT("Enables the new (WIP) material HLSL generator.\n")
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TEXT("0 - Don't allow\n")
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TEXT("1 - Allow if enabled by material\n")
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TEXT("2 - Force all materials to use new generator\n"),
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ECVF_RenderThreadSafe | ECVF_ReadOnly);
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```
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bCompileForComputeShader = Material->IsLightFunction();
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GetPerInstanceCustomDataX分为Vertex与Pixel版本。
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#### FMaterialAttributes
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MaterialTemplate.ush有一处`/** Material declarations */`之后会生成对应FMaterialAttributes结构体，可以在材质编辑器的HLSL中查看生成结果。这与
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- MaterialAttributeDefinitionMap.cpp：FMaterialAttributeDefinitionMap::InitializeAttributeMap()中定义属性。
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- HLSLMaterialTranslator.cpp：GetMaterialShaderCode()中的`for (const FGuid& AttributeID : OrderedVisibleAttributes)`：生成对应属性结构体以及属性获取函数。
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#### DerivativeAutogen.GenerateUsedFunctions()
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```c++
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{
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FString DerivativeHelpers = DerivativeAutogen.GenerateUsedFunctions(*this);
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FString DerivativeHelpersAndResources = DerivativeHelpers + ResourcesString;
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//LazyPrintf.PushParam(*ResourcesString);
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LazyPrintf.PushParam(*DerivativeHelpersAndResources);
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}
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```
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#### GetMaterialEmissiveForCS()以及其他函数
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```c++
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if (bCompileForComputeShader)
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{
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LazyPrintf.PushParam(*GenerateFunctionCode(CompiledMP_EmissiveColorCS, BaseDerivativeVariation));
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}
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else
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{
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LazyPrintf.PushParam(TEXT("return 0"));
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}
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{
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FLinearColor Extinction = Material->GetTranslucentMultipleScatteringExtinction();
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LazyPrintf.PushParam(*FString::Printf(TEXT("return MaterialFloat3(%.5f, %.5f, %.5f)"), Extinction.R, Extinction.G, Extinction.B));
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}
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LazyPrintf.PushParam(*FString::Printf(TEXT("return %.5f"), Material->GetOpacityMaskClipValue()));
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{
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const FDisplacementScaling DisplacementScaling = Material->GetDisplacementScaling();
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LazyPrintf.PushParam(*FString::Printf(TEXT("return %.5f"), FMath::Max(0.0f, DisplacementScaling.Magnitude)));
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LazyPrintf.PushParam(*FString::Printf(TEXT("return %.5f"), FMath::Clamp(DisplacementScaling.Center, 0.0f, 1.0f)));
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}
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LazyPrintf.PushParam(!bEnableExecutionFlow ? *GenerateFunctionCode(MP_WorldPositionOffset, BaseDerivativeVariation) : TEXT("return Parameters.MaterialAttributes.WorldPositionOffset"));
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LazyPrintf.PushParam(!bEnableExecutionFlow ? *GenerateFunctionCode(CompiledMP_PrevWorldPositionOffset, BaseDerivativeVariation) : TEXT("return 0.0f"));
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LazyPrintf.PushParam(!bEnableExecutionFlow ? *GenerateFunctionCode(MP_CustomData0, BaseDerivativeVariation) : TEXT("return 0.0f"));
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LazyPrintf.PushParam(!bEnableExecutionFlow ? *GenerateFunctionCode(MP_CustomData1, BaseDerivativeVariation) : TEXT("return 0.0f"));
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```
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%.5f：表示按浮点数输出，小数点后面取5位其余的舍弃；例如：5/2 “%.5f”输出为：2.50000
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#### MaterialCustomizedUVs & CustomInterpolators
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- `for (uint32 CustomUVIndex = 0; CustomUVIndex < NumUserTexCoords; CustomUVIndex++)`
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- `for (UMaterialExpressionVertexInterpolator* Interpolator : CustomVertexInterpolators`
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### 是否需要Toon
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在材质中：
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```c++
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FMaterialRelevance UMaterialInterface::GetRelevance_Internal(const UMaterial* Material, ERHIFeatureLevel::Type InFeatureLevel) const
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{
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if(Material)
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{
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//YivanLee's Modify 这里仅仅针对人物，因为它决定了是否开启ToonGBuffer，但是对于ToonLevel，ToonFoliage，ToonGrass这里并不需要开启
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bool bUseToonData = MaterialResource->GetShadingModels().HasAnyShadingModel({ MSM_ToonStandard, MSM_ToonSkin, MSM_ToonHair, MSM_ToonFace, MSM_ToonEyeBrow });
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}
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···
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MaterialRelevance.bUsesToonData = bUseToonData;
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···
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}
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```
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在渲染管线中：
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```c++
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//RenderUtils.cpp
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bool IsUsingToonRendering(const FStaticShaderPlatform Platform)
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{
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static FShaderPlatformCachedIniValue<int32> PerPlatformCVar(TEXT("r.ToonRendering.Enable"));
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if (IsMobilePlatform(Platform) || IsForwardShadingEnabled(Platform))//目前不考虑VR与移动端
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{
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return false;
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}
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else
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{
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return (PerPlatformCVar.Get(Platform) == 1);
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}
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}
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bool IsUsingToonOutline(const FStaticShaderPlatform Platform)
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{
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static FShaderPlatformCachedIniValue<int32> PerPlatformCVar(TEXT("r.ToonRendering.ToonOutline"));
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return (PerPlatformCVar.Get(Platform) == 1) && IsUsingToonRendering(Platform);
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}
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bool IsUsingToonRimLighting(const FStaticShaderPlatform Platform)
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{
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static FShaderPlatformCachedIniValue<int32> PerPlatformCVar(TEXT("r.ToonRendering.ToonRimLighting"));
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return (PerPlatformCVar.Get(Platform) == 1) && IsUsingToonRendering(Platform);
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}
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```
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李兄的ToonBuffer判断逻辑：
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```c++
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bool FDeferredShadingSceneRenderer::ShouldRenderToonDataPass() const
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{
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if (!SupportsToonDataMaterials(FeatureLevel, ShaderPlatform))
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{
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return false;
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}
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if (IsForwardShadingEnabled(GetFeatureLevelShaderPlatform(FeatureLevel)))
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{
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return false;
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}
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for (auto& View : Views)
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{
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if (View.ShouldRenderView() && View.ParallelMeshDrawCommandPasses[EMeshPass::ToonDataPass].HasAnyDraw())
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{
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return true;
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}
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}
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return false;
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}
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```
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## Toon PerObjectGBufferData具体功能表
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从3开始，0、1、2已被占用。
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- ?
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## ToonData
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## 高光
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- PBR高光（使用Roughness控制是否可行？是否需要传入GBuffer一个Mask贴图）
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- 自定义高光：高光贴图、高光颜色、参数化高光形状、多层高光
|
||
|
||
# BasePassPixelShader
|
||
Velocity相关代码段：
|
||
```c++
|
||
#if USES_GBUFFER
|
||
// -0.5 .. 0.5, could be optimzed as lower quality noise would be sufficient
|
||
float QuantizationBias = PseudoRandom( MaterialParameters.SvPosition.xy ) - 0.5f;
|
||
|
||
GBuffer.IndirectIrradiance = IndirectIrradiance;
|
||
|
||
// this is the new encode, the older encode is the #else, keeping it around briefly until the new version is confirmed stable.
|
||
#if 1
|
||
{
|
||
// change this so that we can pack everything into the gbuffer, but leave this for now
|
||
#if GBUFFER_HAS_DIFFUSE_SAMPLE_OCCLUSION
|
||
GBuffer.GenericAO = float(GBuffer.DiffuseIndirectSampleOcclusion) * (1.0f / 255.0f);
|
||
#elif ALLOW_STATIC_LIGHTING
|
||
// No space for AO. Multiply IndirectIrradiance by AO instead of storing.
|
||
GBuffer.GenericAO = EncodeIndirectIrradiance(GBuffer.IndirectIrradiance * GBuffer.GBufferAO) + QuantizationBias * (1.0 / 255.0); // Stationary sky light path
|
||
#else
|
||
GBuffer.GenericAO = GBuffer.GBufferAO; // Movable sky light path
|
||
#endif
|
||
|
||
EncodeGBufferToMRT(Out, GBuffer, QuantizationBias);
|
||
|
||
if (GBuffer.ShadingModelID == SHADINGMODELID_UNLIT && !STRATA_ENABLED) // Do not touch what strata outputs
|
||
{
|
||
Out.MRT[1] = 0;
|
||
SetGBufferForUnlit(Out.MRT[2]);
|
||
Out.MRT[3] = 0;
|
||
Out.MRT[GBUFFER_HAS_VELOCITY ? 5 : 4] = 0;
|
||
Out.MRT[GBUFFER_HAS_VELOCITY ? 6 : 5] = 0;
|
||
}
|
||
|
||
#if SINGLE_LAYER_WATER_SEPARATED_MAIN_LIGHT
|
||
// In deferred, we always output the directional light in a separated buffer.
|
||
// This is used to apply distance field shadows or light function to the main directional light.
|
||
// Strata also writes it through MRT because this is faster than through UAV.
|
||
#if STRATA_ENABLED && STRATA_INLINE_SINGLELAYERWATER
|
||
Out.MRT[(GBUFFER_HAS_VELOCITY ? 2 : 1) + (GBUFFER_HAS_PRECSHADOWFACTOR ? 1 : 0)] = float4(SeparatedWaterMainDirLightLuminance * View.PreExposure, 1.0f);
|
||
#else
|
||
if (GBuffer.ShadingModelID == SHADINGMODELID_SINGLELAYERWATER)
|
||
{
|
||
Out.MRT[(GBUFFER_HAS_VELOCITY ? 6 : 5) + (GBUFFER_HAS_PRECSHADOWFACTOR ? 1 : 0)] = float4(SeparatedWaterMainDirLightLuminance * View.PreExposure, 1.0f);
|
||
}
|
||
#endif
|
||
#endif
|
||
}
|
||
```
|
||
|
||
# 顶点色
|
||
## 蓝色协议
|
||
用于存储一些低精度数据，插值即可
|
||
- 顶点色：
|
||
- R:阴影区域控制（强度） 0~1
|
||
- G:描边宽度
|
||
- B:ToonAO
|
||
- 第二套顶点色（UV Channel1）：
|
||
- R:深度偏移
|
||
- G:用来区分内轮廓不同部位的ID
|
||
|
||
蓝色协议的R:阴影区域标记 与 B:AO，而罪恶装备使用贴图来传递信息。
|
||
## 罪恶装备
|
||
对阴影判断阈值的偏移。（见前面着色部分，顶点AO+手绘修正）
|
||
R:阴影偏移
|
||
G:轮廓线根据与相机的距离扩大多少的系数
|
||
B:等高线 Z 轴偏移值
|
||
|
||
# 罪恶装备
|
||
8,G为阴影控（AO），R为高光强度参数，金属和光滑材质的部分设置的更大一些。B通道：用于照明控制。最大值为高光，反之，值越小高光越淡。
|
||
|
||
|
||
https://zhuanlan.zhihu.com/p/360229590一文中介绍了崩坏3与原神的计算方式
|
||
|
||
崩坏3的LightMap计算方式：
|
||
```c++
|
||
half4 baseColor = SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, input.uv.xy);
|
||
half4 LightMapColor = SAMPLE_TEXTURE2D(_LightMap, sampler_LightMap, input.uv.xy);
|
||
half3 ShadowColor = baseColor.rgb * _ShadowMultColor.rgb;
|
||
half3 DarkShadowColor = baseColor.rgb * _DarkShadowMultColor.rgb;
|
||
|
||
//如果SFactor = 0,ShallowShadowColor为一级阴影色,否则为BaseColor。
|
||
float SWeight = (LightMapColor.g * input.color.r + input.lambert) * 0.5 + 1.125;
|
||
float SFactor = floor(SWeight - _ShadowArea);
|
||
half3 ShallowShadowColor = SFactor * baseColor.rgb + (1 - SFactor) * ShadowColor.rgb;
|
||
```
|
||
|
||
二级阴影计算:
|
||
```c++
|
||
//如果SFactor = 0,DarkShadowColor为二级阴影色,否则为一级阴影色。
|
||
SFactor = floor(SWeight - _DarkShadowArea);
|
||
DarkShadowColor = SFactor * (_FixDarkShadow * ShadowColor + (1 - _FixDarkShadow) * ShallowShadowColor) + (1 - SFactor) * DarkShadowColor;
|
||
|
||
// 平滑阴影边缘
|
||
half rampS = smoothstep(0, _ShadowSmooth, input.lambert - _ShadowArea);
|
||
half rampDS = smoothstep(0, _DarkShadowSmooth, input.lambert - _DarkShadowArea);
|
||
ShallowShadowColor.rgb = lerp(ShadowColor, baseColor.rgb, rampS);
|
||
DarkShadowColor.rgb = lerp(DarkShadowColor.rgb, ShadowColor, rampDS);
|
||
|
||
//如果SFactor = 0,FinalColor为二级阴影，否则为一级阴影。
|
||
SFactor = floor(LightMapColor.g * input.color.r + 0.9f);
|
||
half4 FinalColor;
|
||
FinalColor.rgb = SFactor * ShallowShadowColor + (1 - SFactor) * DarkShadowColor;
|
||
```
|
||
|
||
|
||
**罪恶装备**：
|
||
对阴影判断阈值的偏移。（见前面着色部分，顶点AO+手绘修正）
|
||
G : 轮廓线根据与相机的距离扩大多少的系数
|
||
B : 等高线 Z 轴偏移值
|
||
A : 轮廓厚度系数。0.5为标准，1为最大厚度，0为无等高线
|
||
|
||
# 蓝色协议
|
||
[[蓝色协议的方案]]
|
||
|
||
# 米哈游
|