170 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			170 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
## 描边
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- RenderToonOutlineToBaseColor
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- RenderToonOutlineToSceneColor
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相关Shader:
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- ToonDataPassShader.usf
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- ToonOutline.usf
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- ToonShadingModel.ush
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相关RT
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```
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//Begin YivanLee's Modify
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TRefCountPtr<IPooledRenderTarget> SceneColorCopy;
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TRefCountPtr<IPooledRenderTarget> BaseColorCopy;
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TRefCountPtr<IPooledRenderTarget> ToonBufferDepth;
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TRefCountPtr<IPooledRenderTarget> ToonOutlineTexture;
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TRefCountPtr<IPooledRenderTarget> ToonOutlineMaskBlurTexture;
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TRefCountPtr<IPooledRenderTarget> ToonIDOutlineTexture;
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//ToonDataTexture01 is ToonNormal
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TRefCountPtr<IPooledRenderTarget> ToonDataTexture01;
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//ToonDataTexture02 is R: ShadowController G: B: A:
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TRefCountPtr<IPooledRenderTarget> ToonDataTexture02;
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//ToonDataTexture03 is OutlineColorMask and OutlineMask
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TRefCountPtr<IPooledRenderTarget> ToonDataTexture03;
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//ToonDataTexture04 is IDTexture
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TRefCountPtr<IPooledRenderTarget> ToonDataTexture04;
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//End YivanLee's Modify
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```
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### GBuffer
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ToonData0 = float4(N * 0.5 + 0.5, 1.0f);//WorldNormal
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ToonData1 = GetMaterialToonDataA(MaterialParameters);//Shadow controller
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ToonData2 = GetMaterialToonDataB(MaterialParameters);//OutlinleColor,OutlineMask
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ToonData3 = GetMaterialToonDataC(MaterialParameters);//IDTexture,OutlineWidth
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### BasePass部分
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位于FDeferredShadingSceneRenderer::RenderBasePass()最后,
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```
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if (ShouldRenderToonDataPass())
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{
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	//Begin Recreate ToonData Render targets
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	SceneContext.ReleaseToonDataTarget();
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	SceneContext.AllocateToonDataTarget(GraphBuilder.RHICmdList);
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	SceneContext.ReleaseToonDataGBuffer();
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	SceneContext.AllocateToonDataGBuffer(GraphBuilder.RHICmdList);
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	//End Recreate ToonData Render targets
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	TStaticArray<FRDGTextureRef, MaxSimultaneousRenderTargets> ToonDataPassTextures;
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	uint32 ToonDataTextureCount = SceneContext.GetToonDataGBufferRenderTargets(GraphBuilder, ToonDataPassTextures);
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	TArrayView<FRDGTextureRef> ToonDataPassTexturesView = MakeArrayView(ToonDataPassTextures.GetData(), ToonDataTextureCount);
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	ERenderTargetLoadAction ToonTargetsAction;
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	if (bEnableParallelBasePasses)//Windows DirectX12
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	{
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		ToonTargetsAction = ERenderTargetLoadAction::ELoad;
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	}
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	else//Windows DirectX11
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	{
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		ToonTargetsAction = ERenderTargetLoadAction::EClear;
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	}
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	FRenderTargetBindingSlots ToonDataPassRenderTargets = GetRenderTargetBindings(ToonTargetsAction, ToonDataPassTexturesView);
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	ToonDataPassRenderTargets.DepthStencil = FDepthStencilBinding(SceneDepthTexture, ERenderTargetLoadAction::ELoad, ERenderTargetLoadAction::ELoad, ExclusiveDepthStencil);
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	ToonDataPassRenderTargets.ShadingRateTexture = GVRSImageManager.GetVariableRateShadingImage(GraphBuilder, ViewFamily, nullptr, EVRSType::None);
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	AddSetCurrentStatPass(GraphBuilder, GET_STATID(STAT_CLM_ToonDataPass));
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	RenderToonDataPass(GraphBuilder, ToonDataPassTextures, ToonDataTextureCount, ToonDataPassRenderTargets, bEnableParallelBasePasses);
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	AddSetCurrentStatPass(GraphBuilder, GET_STATID(STAT_CLM_AfterToonDataPass));
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	RenderToonOutlineToBaseColor(GraphBuilder, SceneDepthTexture, bEnableParallelBasePasses);
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}
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```
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#### RenderNormalDepthOutline
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- ToonOutlineMain:使用拉普拉斯算子与Sobel算子计算并混合结果。计算Depth与Normal,最后Length(float4(Normal,Depth));
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- ToonIDOutlinePSMain:使用Sobel计算描边。
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#### RenderToonIDOutline
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#### CombineOutlineToBaseColor
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### 渲染管线Render()
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RenderToonOutlineToSceneColor()位于RenderLights()之后与RenderDeferredReflectionsAndSkyLighting()之前的位置。
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## ShaderModel
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### DefaultLitBxDF
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```c#
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Lighting.Diffuse  = AreaLight.FalloffColor * (Falloff * NoL) * Diffuse_Lambert( GBuffer.DiffuseColor );
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Lighting.Specular = AreaLight.FalloffColor * (Falloff * NoL) * SpecularGGX(GBuffer.Roughness, GBuffer.SpecularColor, Context, NoL, AreaLight);
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```
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### Toon
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- ToonDataA:R ShadowOffset   GBA 未使用
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- ToonDataB:RGB OutlineColor A OutlineMask
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- ToonDataC:RGB IDMap        A OutlineWidth 
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- PreIntegratedToonBRDF: R 为NoL 预积分Ramp G 为GGX高光预积分值。
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- PreIntegratedToonSkinBRDF:RGB为皮肤预积分颜色。
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- SubsurfaceColor:该数据存放在CustomData.rgb位置,在天光计算中其作用
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PS.ToonShadingStandard没有使用SubsurfaceColor。
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#### ToonShadingStandard
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在原始的PBR公式做了以下修改:
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固有色部分
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1. 使用ShadowOffset(ToonDataA.r)来控制阴影区域的偏移也就是类似UTS的Step。但使用lerp(Context.NoL, 1.0, ShadowOffset),这导致偏移并不易于控制。
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2. 计算FallOffMask(预积分衰减调整系数)。使用ShadowOffset过的NoL与Metalic作为UV对PreIntegratedToonBRDF图进行查表,返回r值。
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3. Lighting.Diffuse = AreaLight.FalloffColor * FallOffMask * GBuffer.BaseColor / 3.1415927f;
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高光部分
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1. D(预积分GGX),使用NoH与Roughness作为UV对PreIntegratedToonBRDF进行查表,返回g值。
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2. F(边缘光效果系数),return smoothstep(0.67, 1.0, 1 - NoV);
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3. Lighting.Specular = (F + D) * (AreaLight.FalloffColor * GBuffer.SpecularColor * FallOffMask * 8);
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```c++
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float ShadowOffset = GBuffer.ToonDataA.r;
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float FallOffMask = Falloff * GetPreintegratedToonBRDF(lerp(Context.NoL, 1.0, ShadowOffset), GBuffer.Metallic);
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Lighting.Diffuse = AreaLight.FalloffColor * FallOffMask * GBuffer.BaseColor / 3.1415927f;
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float R2 = GBuffer.Roughness * GBuffer.Roughness;
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float ToonGGX = GetPreintegratedToonSpecBRDF(Context.NoH, GBuffer.Roughness);
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float D = lerp(ToonGGX, 0.0, R2);
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float3 F = GetToonF(Context.NoV);
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Lighting.Specular = (F + D) * (AreaLight.FalloffColor * GBuffer.SpecularColor * FallOffMask * 8);
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```
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#### ToonShadingSkin
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在ToonShadingStandard的基础上做了以下修改:
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固有色部分:
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1. 使用ShadowOffset来偏移Context.NoL * Shadow.SurfaceShadow,来获得ShadowMask。
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2. 使用ShadowMask与Opacity作为UV来查询PreIntegratedToonSkinBRDF,返回rgb值。
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3. Lighting.Diffuse = AreaLight.FalloffColor * FallOffMask * GBuffer.BaseColor / 3.1415927f * PreintegratedBRDF;
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高光部分相同。
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#### ToonShadingHair
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在ToonShadingStandard的基础上做了以下修改:
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固有色部分相同。
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高光部分增加各向异性计算:
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```c++
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float3 H = normalize(L + V);
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float HoL = dot(H, geotangent);
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float sinTH = saturate(sqrt(1 - HoL * HoL));
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float spec = pow(sinTH, lerp(256, 4, GBuffer.Roughness));
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float R2 = GBuffer.Roughness * GBuffer.Roughness;
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float3 F = GetToonF(Context.NoV);
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spec += F;
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Lighting.Specular = AreaLight.FalloffColor * FallOffMask * spec * GBuffer.BaseColor;
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```
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#### 天光(环境光)
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阴影部分的光照主要为环境光,逻辑为于ReflectionEnvironmentSkyLighting()
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```
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/*BeginYivanLee's Modify*/
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float3 SkyLighting = float3(0.0, 0.0, 0.0);
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BRANCH
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if(ShadingModelID == SHADINGMODELID_TOONSTANDARD || ShadingModelID == SHADINGMODELID_TOONHAIR || ShadingModelID == SHADINGMODELID_TOONSKIN)
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{
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	float3 SubsurfaceColor = ExtractSubsurfaceColor(GBuffer);
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	float3 SkyToonLighting = GBuffer.BaseColor * SubsurfaceColor.rgb;
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	float3 SkyDiffuseLighting = SkyLightDiffuse(GBuffer, AmbientOcclusion, BufferUV, ScreenPosition, BentNormal, DiffuseColor) * CloudAmbientOcclusion;
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	SkyLighting = lerp(SkyDiffuseLighting, SkyToonLighting, 0.8f);
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}
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else
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{
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	SkyLighting = SkyLightDiffuse(GBuffer, AmbientOcclusion, BufferUV, ScreenPosition, BentNormal, DiffuseColor) * CloudAmbientOcclusion;
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}
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/*EndYivanLee's Modify*/
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``` |