140 lines
6.8 KiB
Markdown
140 lines
6.8 KiB
Markdown
---
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title: 未命名
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date: 2024-05-10 16:30:16
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excerpt:
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tags:
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rating: ⭐
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---
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PostProcesss
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```c++
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void AddPostProcessingPasses(
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FRDGBuilder& GraphBuilder,
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const FViewInfo& View,
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int32 ViewIndex,
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FSceneUniformBuffer& SceneUniformBuffer,
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bool bAnyLumenActive,
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bool bLumenGIEnabled,
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EReflectionsMethod ReflectionsMethod,
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const FPostProcessingInputs& Inputs,
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const Nanite::FRasterResults* NaniteRasterResults,
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FInstanceCullingManager& InstanceCullingManager,
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FVirtualShadowMapArray* VirtualShadowMapArray,
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FLumenSceneFrameTemporaries& LumenFrameTemporaries,
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const FSceneWithoutWaterTextures& SceneWithoutWaterTextures,
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FScreenPassTexture TSRMoireInput)
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{
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RDG_CSV_STAT_EXCLUSIVE_SCOPE(GraphBuilder, RenderPostProcessing);
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QUICK_SCOPE_CYCLE_COUNTER(STAT_PostProcessing_Process);
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check(IsInRenderingThread());
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check(View.VerifyMembersChecks());
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Inputs.Validate();
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FScene* Scene = View.Family->Scene->GetRenderScene();
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const FIntRect PrimaryViewRect = View.ViewRect;
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const FSceneTextureParameters SceneTextureParameters = GetSceneTextureParameters(GraphBuilder, Inputs.SceneTextures);
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const FScreenPassRenderTarget ViewFamilyOutput = FScreenPassRenderTarget::CreateViewFamilyOutput(Inputs.ViewFamilyTexture, View);
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const FScreenPassTexture SceneDepth(SceneTextureParameters.SceneDepthTexture, PrimaryViewRect);
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const FScreenPassTexture CustomDepth(Inputs.CustomDepthTexture, PrimaryViewRect);
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const FScreenPassTexture Velocity(SceneTextureParameters.GBufferVelocityTexture, PrimaryViewRect);
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const FScreenPassTexture BlackDummy(GSystemTextures.GetBlackDummy(GraphBuilder));
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const FTranslucencyPassResources& PostDOFTranslucencyResources = Inputs.TranslucencyViewResourcesMap.Get(ETranslucencyPass::TPT_TranslucencyAfterDOF);
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const FTranslucencyPassResources& PostMotionBlurTranslucencyResources = Inputs.TranslucencyViewResourcesMap.Get(ETranslucencyPass::TPT_TranslucencyAfterMotionBlur);
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```
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# BasePass
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```c++
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#if WITH_EDITOR
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if (ViewFamily.EngineShowFlags.Wireframe)
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{
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checkf(ExclusiveDepthStencil.IsDepthWrite(), TEXT("Wireframe base pass requires depth-write, but it is set to read-only."));
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BasePassTextureCount = 1;
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BasePassTextures[0] = SceneTextures.EditorPrimitiveColor;
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BasePassTexturesView = MakeArrayView(BasePassTextures.GetData(), BasePassTextureCount);
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BasePassDepthTexture = SceneTextures.EditorPrimitiveDepth;
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auto* PassParameters = GraphBuilder.AllocParameters<FRenderTargetParameters>();
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PassParameters->RenderTargets = GetRenderTargetBindings(ERenderTargetLoadAction::EClear, BasePassTexturesView);
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PassParameters->RenderTargets.DepthStencil = FDepthStencilBinding(BasePassDepthTexture, ERenderTargetLoadAction::EClear, ERenderTargetLoadAction::EClear, ExclusiveDepthStencil);
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GraphBuilder.AddPass(RDG_EVENT_NAME("WireframeClear"), PassParameters, ERDGPassFlags::Raster, [](FRHICommandList&) {});
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}
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#endif
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// Render targets bindings should remain constant at this point.
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FRenderTargetBindingSlots BasePassRenderTargets = GetRenderTargetBindings(ERenderTargetLoadAction::ELoad, BasePassTexturesView);
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BasePassRenderTargets.DepthStencil = FDepthStencilBinding(BasePassDepthTexture, ERenderTargetLoadAction::ELoad, ERenderTargetLoadAction::ELoad, ExclusiveDepthStencil);
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FForwardBasePassTextures ForwardBasePassTextures{};
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if (bForwardShadingEnabled)
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{
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ForwardBasePassTextures.SceneDepthIfResolved = SceneTextures.Depth.IsSeparate() ? SceneTextures.Depth.Resolve : nullptr;
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ForwardBasePassTextures.ScreenSpaceAO = SceneTextures.ScreenSpaceAO;
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ForwardBasePassTextures.ScreenSpaceShadowMask = ForwardShadowMaskTexture;
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}
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else if (!ExclusiveDepthStencil.IsDepthWrite())
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{
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// If depth write is not enabled, we can bound the depth texture as read only
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ForwardBasePassTextures.SceneDepthIfResolved = SceneTextures.Depth.Resolve;
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}
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ForwardBasePassTextures.bIs24BitUnormDepthStencil = ForwardBasePassTextures.SceneDepthIfResolved ? GPixelFormats[ForwardBasePassTextures.SceneDepthIfResolved->Desc.Format].bIs24BitUnormDepthStencil : 1;
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GraphBuilder.SetCommandListStat(GET_STATID(STAT_CLM_BasePass));
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RenderBasePassInternal(GraphBuilder, SceneTextures, BasePassRenderTargets, BasePassDepthStencilAccess, ForwardBasePassTextures, DBufferTextures, bDoParallelBasePass, bRenderLightmapDensity, InstanceCullingManager, bNaniteEnabled, NaniteRasterResults);
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GraphBuilder.SetCommandListStat(GET_STATID(STAT_CLM_AfterBasePass));
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FRenderTargetBindingSlots BasePassRenderTargets = GetRenderTargetBindings(ERenderTargetLoadAction::ELoad, BasePassTexturesView);
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BasePassRenderTargets.DepthStencil = FDepthStencilBinding(BasePassDepthTexture, ERenderTargetLoadAction::ELoad, ERenderTargetLoadAction::ELoad, ExclusiveDepthStencil);
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RenderBasePassInternal(GraphBuilder, SceneTextures, BasePassRenderTargets, BasePassDepthStencilAccess, ForwardBasePassTextures, DBufferTextures, bDoParallelBasePass, bRenderLightmapDensity, InstanceCullingManager, bNaniteEnabled, NaniteRasterResults);
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```
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## 读取GBufferTexture
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位于SceneRendering.h
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```c++
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FORCEINLINE FSceneTextures& GetActiveSceneTextures() { return ViewFamily.GetSceneTextures(); }
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```
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考虑使用形参
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- const FSceneTextures* SceneTextures
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- const FSceneTextures& SceneTextures
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- FSceneTextures& SceneTextures
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# UE5.4的FScreenTransform计算
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参考：VisualizeMotionVectors.cpp
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- FScreenTransform::SvPositionToViewportUV(Output.ViewRect)：**SvPosition => ViewportUV**
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- `FScreenTransform SvPositionToViewportUV = FScreenTransform::SvPositionToViewportUV(Output.ViewRect);`
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- FScreenTransform::ViewportUVToScreenPos()：**ViewportUV => ScreenPos**
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- FScreenTransform::ChangeTextureBasisFromTo()：坐标转换。比如下面的坐标是**ViewportUV => TextureUV**
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- ```FScreenTransform::ChangeTextureBasisFromTo(Inputs.SceneColor, FScreenTransform::ETextureBasis::ViewportUV, FScreenTransform::ETextureBasis::TextureUV);```
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- **SvPosition => ScreenPos**：SvPositionToViewportUV * FScreenTransform::ViewportUVToScreenPos
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这是用于重采样后2个RT大小不一样而进行的计算。
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# OutlinePass
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## 距离对于后处理深度描边的关系
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需要针对极近距离进行处理。
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- 最大深度采样值的最小值为100
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| 距离 | 最小深度采样 | 最大深度采样 |
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| :-----: | :----: | :----: |
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| 100cm | 1 | 10 |
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| 200cm | 2 | 20 |
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| 500cm | 5 | 50 |
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| 1000cm | | 100 |
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| 2000cm | | |
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| 5000cm | | |
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| 10000cm | | |
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# 问题记录
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## 处于FarDepthValue的Outline被裁剪的问题
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- SkyAtmosphere.usf中，会将天空球渲染在深度为FarDepthValue的像素上，这样会将一些Outline覆盖掉。
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- HeightFogPixelShader.usf中，会通过判断**DeviceZ != 0.0** 来调整渲染结果，绘制方式PSO.BlendState = TStaticBlendState<CW_RGB, BO_Add, BF_One, BF_SourceAlpha>::GetRHI(); |