331 lines
17 KiB
Markdown
331 lines
17 KiB
Markdown
|
---
|
|||
|
|
title: UE5RayTracing渲染管线笔记——(1)
|
|||
|
|
date: 2022-08-09 13:55:15
|
|||
|
|
tags: RayTracing
|
|||
|
|
rating: ⭐️⭐️
|
|||
|
|
---
|
|||
|
|
## 任务
|
|||
|
|
- [ ] 查看这个如何针对各个View构建场景
|
|||
|
|
|
|||
|
|
## 渲染事件
|
|||
|
|
RayTracingScene位于LumenSceneUpdate之后。
|
|||
|
|
|
|||
|
|
## 收集场景信息
|
|||
|
|
### 场景信息
|
|||
|
|
在FScene中定了这2个变量来存储RayTracing专用的场景信息：
|
|||
|
|
```c#
|
|||
|
|
FRayTracingScene RayTracingScene;
|
|||
|
|
TArray<FLightSceneInfo*, TInlineAllocator<4>> RayTracedLights;
|
|||
|
|
```
|
|||
|
|
FRayTracingScene还存储着FRayTracingGeometryInstance数组、TArray<const FRayTracingGeometry*> GeometriesToBuild、RayTracingSceneBuffer、RayTracingSceneSRV。
|
|||
|
|
|
|||
|
|
### 收集过程
|
|||
|
|
主要的逻辑位于GatherRayTracingWorldInstancesForView()中，通过RayTracingCollector来收集场景中的图元。在FSceneRenderer定义了MeshCollector与RayTracingCollector，其中MeshCollector的GatherDynamicMeshElements()在计算可见性阶段被调用()。
|
|||
|
|
```c#
|
|||
|
|
// Gather mesh instances, shaders, resources, parameters, etc. and build ray tracing acceleration structure
|
|||
|
|
FRayTracingScene& RayTracingScene = Scene->RayTracingScene;
|
|||
|
|
RayTracingScene.Reset(); // Resets the internal arrays, but does not release any resources.
|
|||
|
|
|
|||
|
|
const int32 ReferenceViewIndex = 0;
|
|||
|
|
FViewInfo& ReferenceView = Views[ReferenceViewIndex];
|
|||
|
|
|
|||
|
|
// Prepare the scene for rendering this frame.
|
|||
|
|
GatherRayTracingWorldInstancesForView(GraphBuilder, ReferenceView, RayTracingScene);
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
- GatherRayTracingWorldInstancesForView()
|
|||
|
|
- FGPUScenePrimitiveCollector DummyDynamicPrimitiveCollector;
|
|||
|
|
- 给RayTracingCollector的内部变量赋值：RayTracingCollector.AddViewMeshArrays(&View,&View.RayTracedDynamicMeshElements,&View.SimpleElementCollector,&DummyDynamicPrimitiveCollector,ViewFamily.GetFeatureLevel(),&DynamicIndexBufferForInitViews,&DynamicVertexBufferForInitViews,&DynamicReadBufferForInitViews);
|
|||
|
|
- 创建Mesh资源收集器：`View.RayTracingMeshResourceCollector = MakeUnique<FRayTracingMeshResourceCollector>(...);`
|
|||
|
|
- 初始化Rtx裁剪变量：View.RayTracingCullingParameters.Init(View);
|
|||
|
|
- 创建FRayTracingMaterialGatheringContext MaterialGatheringContext{Scene,&View,ViewFamily,GraphBuilder,*View.RayTracingMeshResourceCollector};
|
|||
|
|
- 声明FRelevantPrimitive结构体，实现InstancingKey()用于返回图元类型掩码。并定义FRelevantPrimitive数组，长度为场景图元总数。
|
|||
|
|
- 遍历所有图元，
|
|||
|
|
|
|||
|
|
### 加速结构构建
|
|||
|
|
>RayTracingGem中有提到了加速结构的Rebuild与Refit概念。
|
|||
|
|
|
|||
|
|
该步骤会在BasePass()之前调用。DispatchRayTracingWorldUpdates()的注释说：
|
|||
|
|
>异步构建可能会与BasePass重合。 Async AS builds can potentially overlap with BasePass
|
|||
|
|
|
|||
|
|
GeometriesToBuild在GatherRayTracingWorldInstancesForView()被填充，之后在DispatchRayTracingWorldUpdates()中通过**GRayTracingGeometryManager.ForceBuildIfPending(GraphBuilder.RHICmdList, RayTracingScene.GeometriesToBuild);**更新。
|
|||
|
|
|
|||
|
|
- FRayTracingGeometryManager GRayTracingGeometryManager：全局的场景管理类。
|
|||
|
|
- ForceBuildIfPending()：添加需要强制构建的多边形。
|
|||
|
|
- ProcessBuildRequests()：在排序请求后，调用**InCmdList.BuildAccelerationStructures(BuildParams);**构建加速结构。Render() 2634 =>DispatchRayTracingWorldUpdates()=>ProcessBuildRequests()=>InCmdList.BuildAccelerationStructures(BuildParams);
|
|||
|
|
|
|||
|
|
加速结构存在一个UAV上，以FRayTracingGeometryBuildParams为单位。里面存储了`FRayTracingGeometryRHIRef Geometry、BuildMode、以及TArrayView<const FRayTracingGeometrySegment> Segments;`
|
|||
|
|
|
|||
|
|
### FRayTracingScene
|
|||
|
|
使用这个类来管理Rtx场景。
|
|||
|
|
|
|||
|
|
## RayTracingCommon.h
|
|||
|
|
UE使用宏来简化RayTracingShader的编写。 比如RayTracingShader入口函数：
|
|||
|
|
```c++
|
|||
|
|
#ifndef RAY_TRACING_ENTRY_RAYGEN
|
|||
|
|
#define RAY_TRACING_ENTRY_RAYGEN(name)\
|
|||
|
|
[shader("raygeneration")] void name()
|
|||
|
|
#endif // RAY_TRACING_ENTRY_RAYGEN
|
|||
|
|
|
|||
|
|
#ifndef RAY_TRACING_ENTRY_INTERSECTION
|
|||
|
|
#define RAY_TRACING_ENTRY_INTERSECTION(name)\
|
|||
|
|
[shader("intersection")] void name()
|
|||
|
|
#endif //RAY_TRACING_ENTRY_INTERSECTION
|
|||
|
|
|
|||
|
|
#ifndef RAY_TRACING_ENTRY_CLOSEST_HIT
|
|||
|
|
#define RAY_TRACING_ENTRY_CLOSEST_HIT(name, payload_type, payload_name, attributes_type, attributes_name)\
|
|||
|
|
[shader("closesthit")] void name(inout payload_type payload_name, in attributes_type attributes_name)
|
|||
|
|
#endif //RAY_TRACING_ENTRY_CLOSEST_HIT
|
|||
|
|
|
|||
|
|
#ifndef RAY_TRACING_ENTRY_ANY_HIT
|
|||
|
|
#define RAY_TRACING_ENTRY_ANY_HIT(name, payload_type, payload_name, attributes_type, attributes_name)\
|
|||
|
|
[shader("anyhit")] void name(inout payload_type payload_name, in attributes_type attributes_name)
|
|||
|
|
#endif // RAY_TRACING_ENTRY_ANY_HIT
|
|||
|
|
|
|||
|
|
#ifndef RAY_TRACING_ENTRY_MISS
|
|||
|
|
#define RAY_TRACING_ENTRY_MISS(name, payload_type, payload_name)\
|
|||
|
|
[shader("miss")] void name(inout payload_type payload_name)
|
|||
|
|
#endif //RAY_TRACING_ENTRY_MISS
|
|||
|
|
```
|
|||
|
|
所以Name需要与**IMPLEMENT_GLOBAL_SHADER**中定义的Shader入口函数名相同。
|
|||
|
|
|
|||
|
|
RayTracing函数：
|
|||
|
|
- FMinimalPayload Payload=TraceVisibilityRay()
|
|||
|
|
- FMaterialClosestHitPayload Payload = TraceMaterialRay()
|
|||
|
|
|
|||
|
|
以及其他工具函数：
|
|||
|
|
- DispatchRaysIndex()
|
|||
|
|
- GetPixelCoord()
|
|||
|
|
|
|||
|
|
## RenderRayTracingReflections
|
|||
|
|
- SortedDeferred
|
|||
|
|
|
|||
|
|
FRayTracingDeferredReflectionsRGS
|
|||
|
|
|
|||
|
|
## RenderDiffuseIndirectAndAmbientOcclusion
|
|||
|
|
RenderRayTracingAmbientOcclusion()
|
|||
|
|
- 遍历每个View
|
|||
|
|
- 计算使用对应方式计算GI。将结果传递给FDiffuseIndirectInputs对象。
|
|||
|
|
- 通过AmbientOcclusionRGS()RayTracing降噪得到AmbientOcclusionMask并传递给FDiffuseIndirectInputs.AmbientOcclusionMask。
|
|||
|
|
- 如果有头发会多渲染头发的AO。
|
|||
|
|
- 调用FDiffuseIndirectCompositePS将之前的渲染结果与GI、AO效果合成在一起。
|
|||
|
|
|
|||
|
|
FDiffuseIndirectCompositePS()
|
|||
|
|
|
|||
|
|
### AmbientOcclusionRGS
|
|||
|
|
RayTracingAmbientOcclusionRGS.usf
|
|||
|
|
|
|||
|
|
- 计算UV、当前像素的FGBufferData以及WorldPosition与CameraDirection
|
|||
|
|
- 对于非SHADINGMODELID_TWOSIDED_FOLIAGE并且开启CONFIG_SHOOT_WITH_GEOMETRIC_NORMAL，则重新计算法线：
|
|||
|
|
- 通过HalfFOV * WorldDepth * ViewInvSize.z，计算像素半径
|
|||
|
|
- 计算通过DDX与DDY计算几何法线。
|
|||
|
|
- 计算3个球形高斯分布（没看懂）。
|
|||
|
|
- 初始化RayTracing相关变量开始RayTracing。如果不开启追踪，将**Visibility = 1.0;RayCount = SamplesPerPixel;SamplesPerPixelLocal = 0.0;**
|
|||
|
|
- 使用RandomSequence生成随机样本。之后调用GenerateCosineNormalRay()，生成Ray。
|
|||
|
|
1. 调用RandomSequence_GenerateSample2D()取得2维随机样本。默认使用Sobol低差异序列，其他还有Halton与Hash随机(https://github.com/skeeto/hash-prospector)
|
|||
|
|
2. 进行余弦-半球采样并转换局部坐标为世界空间。
|
|||
|
|
3. 完成Ray的初始化。
|
|||
|
|
- 调用ApplyCameraRelativeDepthBias()，对Ray的起点进行摄像机->像素坐标方向的偏移一个ε，以解决浮点数不精确的问题。
|
|||
|
|
- 计算光线采样权重， **max(dot(WorldNormal, Ray.Direction), 0.05) / max(RayPDF, 0.05);**
|
|||
|
|
- 调用TraceVisibilityRay()进行RayTracing。
|
|||
|
|
- 累加采样结果。Tracing范围内没有遮挡物Visibility就是1，否则就是1-IntensityLocal。该值为后处理空间里设定的AO亮度值RayTracingAOIntensity。如果Ray Hit还会设置新的ClosestRayHitDistance值。
|
|||
|
|
- 输出结果。 OcclusionMask=ShadingDotGeometric * (Visibility / RayCount);HitDistance=ClosestRayHitDistance;（这两个UAV都是屏幕空间降噪器的贴图变量，Shader处理完之后会进行降噪处理）
|
|||
|
|
- 否则直接使用世界法线，ShadingDotGeometric=1.0
|
|||
|
|
|
|||
|
|
## RenderRayTracingSkyLight
|
|||
|
|
- 初始化FPathTracingSkylight SkylightParameters与FSkyLightData SkyLightData，如果天光功能未开启则返回黑色OutSkyLightTexture与OutHitDistanceTexture。
|
|||
|
|
- 使用CVarRayTracingSkyLightScreenPercentage计算ResolutionFraction。
|
|||
|
|
- 创建RDG Texture资源RayTracingSkylight与RayTracingSkyLightHitDistance。
|
|||
|
|
- 调用GenerateSkyLightVisibilityRays()生成Ray样本集（256*256），格式为`RWStructuredBuffer<SkyLightVisibilityRays>`，`SkyLightVisibilityRays为方向与PDF值，float4 DirectionAndPdf;`。
|
|||
|
|
- FGenerateSkyLightVisibilityRaysCS的流程
|
|||
|
|
1. 计算坐标UAV坐标与SkyLightSamplingStrategyPdf（会使用SkylightPdf）。
|
|||
|
|
- 大概率是在PrepareSkyTexture()中进行了资源绑定SkylightParameters->SkylightPdf = GraphBuilder.RegisterExternalTexture(Scene->PathTracingSkylightPdf, TEXT("PathTracer.SkylightPdf"));
|
|||
|
|
2. 计算每个像素数据。
|
|||
|
|
1. 生成随机序列，使用Hilbert curve算法: https://github.com/hcs0/Hackers-Delight/blob/master/hilbert/hil_s_from_xy.c.txt
|
|||
|
|
2. 使用Sobol算子采样来得到样本。
|
|||
|
|
3. 使用样本来计算天光采样结果,这一步会根据上下半球进行区分。
|
|||
|
|
- ```FSkyLightSample {float3 Direction;float3 Radiance;float Pdf;};```
|
|||
|
|
4. 计算最终的半球混合PDF：float MisWeightOverPdf = 1.0 / lerp(UniformPdf, SkyLightPdf, SkyLightSamplingStrategyPdf);
|
|||
|
|
5. 计算Ray的Index，并将结果写入。
|
|||
|
|
- 创建用于输出结果的UAV对象OutSkyLightTexture、OutHitDistanceTexture，并且取得SceneTextures。
|
|||
|
|
- 遍历所有View计算天光结果。
|
|||
|
|
- 填充FRayTracingSkyLightRGS::FParameters。如果视口内有头发，将会额外绑定HairStrandsVoxelUniformParameters。
|
|||
|
|
- 设置FRayTracingSkyLightRGS变体。
|
|||
|
|
- 计算FIntPoint RayTracingResolution = View.ViewRect.Size() / UpscaleFactor;
|
|||
|
|
- RayTraceDispatch()。
|
|||
|
|
- Denoising
|
|||
|
|
- 如果SceneViewState有效，返回SkyLightVisibilityRaysDimensions。
|
|||
|
|
|
|||
|
|
- 合成SkyLight
|
|||
|
|
|
|||
|
|
### FRayTracingSkyLightRGS
|
|||
|
|
FRayTracingSkyLightRGS是一个GlobalShader，但因为是一个RayTracing Shader，所以宏的类型为：
|
|||
|
|
```c++
|
|||
|
|
IMPLEMENT_GLOBAL_SHADER(FRayTracingSkyLightRGS, "/Engine/Private/Raytracing/RaytracingSkylightRGS.usf", "SkyLightRGS", SF_RayGen);
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
TLAS数据位于通过Scene->RayTracingScene->RayTracingSceneSRV。
|
|||
|
|
```c++
|
|||
|
|
PassParameters->TLAS = View.GetRayTracingSceneViewChecked();
|
|||
|
|
|
|||
|
|
FRHIShaderResourceView* FViewInfo::GetRayTracingSceneViewChecked() const
|
|||
|
|
{
|
|||
|
|
FRHIShaderResourceView* Result = nullptr;
|
|||
|
|
check(Family);
|
|||
|
|
if (Family->Scene)
|
|||
|
|
{
|
|||
|
|
if (FScene* Scene = Family->Scene->GetRenderScene())
|
|||
|
|
{
|
|||
|
|
Result = Scene->RayTracingScene.GetShaderResourceViewChecked();
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
checkf(Result, TEXT("Ray tracing scene SRV is expected to be created at this point."));
|
|||
|
|
return Result;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
FRHIShaderResourceView* FRayTracingScene::GetShaderResourceViewChecked() const
|
|||
|
|
{
|
|||
|
|
checkf(RayTracingSceneSRV.IsValid(), TEXT("Ray tracing scene SRV was not created. Perhaps BeginCreate() was not called."));
|
|||
|
|
return RayTracingSceneSRV.GetReference();
|
|||
|
|
}
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
#### AddPass
|
|||
|
|
RayGem的AddPass()标记为ERDGPassFlags::Compute。RHICmdList.RayTraceDispatch()需要RayGem管线状态、Shader、RayTracingSceneRHI、RayTracing资源与分辨率。
|
|||
|
|
FRayTracingPipelineStateInitializer管线状态需要:
|
|||
|
|
- MaxPayloadSizeInBytes
|
|||
|
|
- RayGenShaderTable
|
|||
|
|
- HitGroupTable
|
|||
|
|
- bAllowHitGroupIndexing
|
|||
|
|
|
|||
|
|
```c++
|
|||
|
|
FIntPoint RayTracingResolution = View.ViewRect.Size() / UpscaleFactor;
|
|||
|
|
GraphBuilder.AddPass(
|
|||
|
|
RDG_EVENT_NAME("SkyLightRayTracing %dx%d", RayTracingResolution.X, RayTracingResolution.Y),
|
|||
|
|
PassParameters,
|
|||
|
|
ERDGPassFlags::Compute,
|
|||
|
|
[PassParameters, this, &View, RayGenerationShader, RayTracingResolution](FRHIRayTracingCommandList& RHICmdList)
|
|||
|
|
{
|
|||
|
|
//资源绑定，将Texture、UniformStruct绑定的工具函数
|
|||
|
|
FRayTracingShaderBindingsWriter GlobalResources;
|
|||
|
|
SetShaderParameters(GlobalResources, RayGenerationShader, *PassParameters);
|
|||
|
|
|
|||
|
|
//取得RayTracing管线状态
|
|||
|
|
FRayTracingPipelineState* Pipeline = View.RayTracingMaterialPipeline;
|
|||
|
|
|
|||
|
|
//如果没开启RayTracing天光材质，则重新创建一个RayTracing管线状态。看得出主要需求RayGemShader与HitGroupTable
|
|||
|
|
if (CVarRayTracingSkyLightEnableMaterials.GetValueOnRenderThread() == 0)
|
|||
|
|
{
|
|||
|
|
// Declare default pipeline
|
|||
|
|
FRayTracingPipelineStateInitializer Initializer;
|
|||
|
|
Initializer.MaxPayloadSizeInBytes = RAY_TRACING_MAX_ALLOWED_PAYLOAD_SIZE; // sizeof(FPackedMaterialClosestHitPayload)
|
|||
|
|
FRHIRayTracingShader* RayGenShaderTable[] = { RayGenerationShader.GetRayTracingShader() };
|
|||
|
|
Initializer.SetRayGenShaderTable(RayGenShaderTable);
|
|||
|
|
|
|||
|
|
FRHIRayTracingShader* HitGroupTable[] = { View.ShaderMap->GetShader<FOpaqueShadowHitGroup>().GetRayTracingShader() };
|
|||
|
|
Initializer.SetHitGroupTable(HitGroupTable);
|
|||
|
|
Initializer.bAllowHitGroupIndexing = false; // Use the same hit shader for all geometry in the scene by disabling SBT indexing.
|
|||
|
|
|
|||
|
|
Pipeline = PipelineStateCache::GetAndOrCreateRayTracingPipelineState(RHICmdList, Initializer);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
FRHIRayTracingScene* RayTracingSceneRHI = View.GetRayTracingSceneChecked();
|
|||
|
|
RHICmdList.RayTraceDispatch(Pipeline, RayGenerationShader.GetRayTracingShader(), RayTracingSceneRHI, GlobalResources, RayTracingResolution.X, RayTracingResolution.Y);
|
|||
|
|
});
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
#### Shader
|
|||
|
|
- 计算DispatchThreadId以及对应的屏幕UV。并且取得对应的FGBufferData。
|
|||
|
|
- 计算出WorldPosition以及CameraDirection。
|
|||
|
|
- 判断是否需要追踪光线: 是否是有限深度 && 当前像素的ShaderModel不是Unlit。如果需要追踪采样数为传入Shader的 SkyLight.SamplesPerPixel，否则为0。
|
|||
|
|
- 调用SkyLightEvaluate()，进行光追计算。
|
|||
|
|
- 初始化相关函数。
|
|||
|
|
- 计算天光采样PDF。
|
|||
|
|
- 采样循环
|
|||
|
|
- 根据bDecoupleSampleGeneration()，选择执行使用SkyLightVisibilityRays的样本 或者使用随机序列生成样本。
|
|||
|
|
- 如果当前像素的ShadingModel是Hair，需要重新计算CurrentWorldNormal。
|
|||
|
|
- 偏移当前光线的深度，并计算NoL。
|
|||
|
|
- 设置RayFlags，并且调用TraceVisibilityRay()进行光线追踪。返回FMinimalPayload（存光线命中距离信息）
|
|||
|
|
- 如果命中，累加RayDistance与HitCount。如没命中，累加BentNormal，并且计算FDirectLighting（光照计算，Hair会用另一套计算方式），最后累加ExitantRadiance、DiffuseThroughput、DiffuseExitantRadiance。
|
|||
|
|
- ExitantRadiance、DiffuseThroughput、DiffuseExitantRadiance除以样本数目（HitDistance = RayDistance / HitCount）。
|
|||
|
|
- 如果当前像素的ShadingModel是Hair，增加头发多重散射贡献值。
|
|||
|
|
- 合成估算结果。DiffuseExitantRadiance.r = Albedo.r > 0.0 ? DiffuseExitantRadiance.r / Albedo.r : DiffuseExitantRadiance.r;
|
|||
|
|
- 乘以曝光值。
|
|||
|
|
- 返回RWSkyOcclusionMaskUAV[DispatchThreadId]=float4(ClampToHalfFloatRange(DiffuseExitantRadiance.rgb), AmbientOcclusion);RWSkyOcclusionRayDistanceUAV[DispatchThreadId] = float2(HitDistance, SamplesPerPixel);
|
|||
|
|
|
|||
|
|
#### 降噪（Denoising）
|
|||
|
|
- 调用IScreenSpaceDenoiser接口取得默认降噪器
|
|||
|
|
- 设置IScreenSpaceDenoiser::FDiffuseIndirectInputs的Color与RayHitDistance(OutSkyLightTexture、OutHitDistanceTexture)
|
|||
|
|
- 设置IScreenSpaceDenoiser::FAmbientOcclusionRayTracingConfig的ResolutionFraction与RayCountPerPixel(ResolutionFraction、GetSkyLightSamplesPerPixel(SkyLight))
|
|||
|
|
- 调用DenoiseSkyLight()输出降噪后的结果覆盖OutSkyLightTexture。
|
|||
|
|
|
|||
|
|
```c++
|
|||
|
|
if (GRayTracingSkyLightDenoiser != 0)
|
|||
|
|
{
|
|||
|
|
//取得默认降噪器
|
|||
|
|
const IScreenSpaceDenoiser* DefaultDenoiser = IScreenSpaceDenoiser::GetDefaultDenoiser();
|
|||
|
|
const IScreenSpaceDenoiser* DenoiserToUse = DefaultDenoiser;// GRayTracingGlobalIlluminationDenoiser == 1 ? DefaultDenoiser : GScreenSpaceDenoiser;
|
|||
|
|
|
|||
|
|
//降噪器变量结构体需要使用之前的渲染结果以及Hit距离结果
|
|||
|
|
IScreenSpaceDenoiser::FDiffuseIndirectInputs DenoiserInputs;
|
|||
|
|
DenoiserInputs.Color = OutSkyLightTexture;
|
|||
|
|
DenoiserInputs.RayHitDistance = OutHitDistanceTexture;
|
|||
|
|
|
|||
|
|
{
|
|||
|
|
//初始化RayTracingConfig
|
|||
|
|
IScreenSpaceDenoiser::FAmbientOcclusionRayTracingConfig RayTracingConfig;
|
|||
|
|
RayTracingConfig.ResolutionFraction = ResolutionFraction;
|
|||
|
|
RayTracingConfig.RayCountPerPixel = GetSkyLightSamplesPerPixel(SkyLight);
|
|||
|
|
|
|||
|
|
RDG_EVENT_SCOPE(GraphBuilder, "%s%s(SkyLight) %dx%d",
|
|||
|
|
DenoiserToUse != DefaultDenoiser ? TEXT("ThirdParty ") : TEXT(""),
|
|||
|
|
DenoiserToUse->GetDebugName(),
|
|||
|
|
View.ViewRect.Width(), View.ViewRect.Height());
|
|||
|
|
|
|||
|
|
//降噪
|
|||
|
|
IScreenSpaceDenoiser::FDiffuseIndirectOutputs DenoiserOutputs = DenoiserToUse->DenoiseSkyLight(
|
|||
|
|
GraphBuilder,
|
|||
|
|
View,
|
|||
|
|
&View.PrevViewInfo,
|
|||
|
|
SceneTextures,
|
|||
|
|
DenoiserInputs,
|
|||
|
|
RayTracingConfig);
|
|||
|
|
|
|||
|
|
//输出结果
|
|||
|
|
OutSkyLightTexture = DenoiserOutputs.Color;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
## RenderRayTracingDebug
|
|||
|
|
位于渲染Fog与Translucency、VirtualTextureFeedbackEnd()之后
|
|||
|
|
```c++
|
|||
|
|
#if RHI_RAYTRACING
|
|||
|
|
if (IsRayTracingEnabled())
|
|||
|
|
{
|
|||
|
|
// Path tracer requires the full ray tracing pipeline support, as well as specialized extra shaders.
|
|||
|
|
// Most of the ray tracing debug visualizations also require the full pipeline, but some support inline mode.
|
|||
|
|
|
|||
|
|
if (ViewFamily.EngineShowFlags.PathTracing
|
|||
|
|
&& FDataDrivenShaderPlatformInfo::GetSupportsPathTracing(Scene->GetShaderPlatform()))
|
|||
|
|
{
|
|||
|
|
for (const FViewInfo& View : Views)
|
|||
|
|
{
|
|||
|
|
RenderPathTracing(GraphBuilder, View, SceneTextures.UniformBuffer, SceneTextures.Color.Target);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
else if (ViewFamily.EngineShowFlags.RayTracingDebug)
|
|||
|
|
{
|
|||
|
|
for (const FViewInfo& View : Views)
|
|||
|
|
{
|
|||
|
|
RenderRayTracingDebug(GraphBuilder, View, SceneTextures.Color.Target);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
#endif
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
DebugVisualizationMode具有3中模式：
|
|||
|
|
- TRAVERSAL：使用ComputeShader
|
|||
|
|
- RAY_TRACING_DEBUG_VIZ_PRIMARY_RAYS：使用SF_RayGen，FRayTracingPrimaryRaysRGS
|
|||
|
|
- DebugVisualizationMode == RAY_TRACING_DEBUG_VIZ_INSTANCES || DebugVisualizationMode == RAY_TRACING_DEBUG_VIZ_TRIANGLES;使用SF_RayGen，FRayTracingDebugRGS
|