LumenTracingUtils.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "RHIDefinitions.h"
#include "DistanceFieldLightingShared.h"
#include "LumenSceneData.h"
#include "IndirectLightRendering.h"
#include "ReflectionEnvironment.h"
#include "FogRendering.h"
#include "SceneView.h"
#include "HZB.h"
 
DECLARE_UNIFORM_BUFFER_STRUCT(FSceneUniformParameters, RENDERER_API)
 
class FLumenCardUpdateContext;
namespace LumenRadianceCache { class FRadianceCacheInputs; }
 
class FHemisphereDirectionSampleGenerator
{
public:
    TArray<FVector4f> SampleDirections;
    float ConeHalfAngle = 0;
    int32 Seed = 0;
    int32 PowerOfTwoDivisor = 1;
    bool bFullSphere = false;
    bool bCosineDistribution = false;
 
    void GenerateSamples(int32 TargetNumSamples, int32 InPowerOfTwoDivisor, int32 InSeed, bool bInFullSphere = false, bool bInCosineDistribution = false);
 
    void GetSampleDirections(const FVector4f*& OutDirections, int32& OutNumDirections) const
    {
        OutDirections = SampleDirections.GetData();
        OutNumDirections = SampleDirections.Num();
    }
};
 
BEGIN_SHADER_PARAMETER_STRUCT(FLumenCardTracingParameters, )
    SHADER_PARAMETER_STRUCT_REF(FViewUniformShaderParameters, View)
    SHADER_PARAMETER_RDG_UNIFORM_BUFFER(FSceneUniformParameters, Scene)
    SHADER_PARAMETER_RDG_UNIFORM_BUFFER(FReflectionUniformParameters, ReflectionStruct)
    SHADER_PARAMETER_RDG_UNIFORM_BUFFER(FLumenCardScene, LumenCardScene)
    SHADER_PARAMETER(float, DiffuseColorBoost)
    SHADER_PARAMETER(FVector3f, SkylightLeakingColor)
    SHADER_PARAMETER(float, ReflectionSkylightLeakingAverageAlbedo)
    SHADER_PARAMETER(float, SkylightLeakingRoughness)
    SHADER_PARAMETER(float, InvFullSkylightLeakingDistance)
    SHADER_PARAMETER(float, CachedLightingPreExposure)
    SHADER_PARAMETER(float, OneOverCachedLightingPreExposure)
 
    SHADER_PARAMETER(uint32, SampleHeightFog)
    SHADER_PARAMETER_RDG_UNIFORM_BUFFER(FFogUniformParameters, FogUniformParameters)
 
    SHADER_PARAMETER_RDG_BUFFER_UAV(RWStructuredBuffer<uint>, RWCardPageLastUsedBuffer)
    SHADER_PARAMETER_RDG_BUFFER_UAV(RWStructuredBuffer<uint>, RWCardPageHighResLastUsedBuffer)
    SHADER_PARAMETER_RDG_BUFFER_UAV(RWStructuredBuffer<uint>, RWSurfaceCacheFeedbackBufferAllocator)
    SHADER_PARAMETER_RDG_BUFFER_UAV(RWStructuredBuffer<uint2>, RWSurfaceCacheFeedbackBuffer)
    SHADER_PARAMETER(uint32, SurfaceCacheFeedbackBufferSize)
    SHADER_PARAMETER(uint32, SurfaceCacheFeedbackBufferTileWrapMask)
    SHADER_PARAMETER(FIntPoint, SurfaceCacheFeedbackBufferTileJitter)
    SHADER_PARAMETER(float, SurfaceCacheFeedbackResLevelBias)
    SHADER_PARAMETER(uint32, SurfaceCacheUpdateFrameIndex)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, DirectLightingAtlas)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, IndirectLightingAtlas)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, FinalLightingAtlas)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, AlbedoAtlas)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, OpacityAtlas)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, NormalAtlas)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, EmissiveAtlas)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, DepthAtlas)
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint4>, TileShadowDownsampleFactorAtlasForResampling)
    SHADER_PARAMETER_RDG_BUFFER_SRV(StructuredBuffer<float4>, GlobalDistanceFieldPageObjectGridBuffer)
    SHADER_PARAMETER(uint32, NumGlobalSDFClipmaps)
END_SHADER_PARAMETER_STRUCT()
 
extern void GetLumenCardTracingParameters(
    FRDGBuilder& GraphBuilder,
    const FViewInfo& View,
    const FLumenSceneData& LumenSceneData,
    const FLumenSceneFrameTemporaries& FrameTemporaries,
    bool bSurfaceCacheFeedback,
    FLumenCardTracingParameters& TracingParameters);
 
BEGIN_SHADER_PARAMETER_STRUCT(FLumenMeshSDFTracingParameters, )
    SHADER_PARAMETER_STRUCT_INCLUDE(FDistanceFieldObjectBufferParameters, DistanceFieldObjectBuffers)
    SHADER_PARAMETER_STRUCT_INCLUDE(FDistanceFieldAtlasParameters, DistanceFieldAtlas)
    SHADER_PARAMETER(float, MeshSDFNotCoveredExpandSurfaceScale)
    SHADER_PARAMETER(float, MeshSDFNotCoveredMinStepScale)
    SHADER_PARAMETER(float, MeshSDFDitheredTransparencyStepThreshold)
END_SHADER_PARAMETER_STRUCT()
 
BEGIN_SHADER_PARAMETER_STRUCT(FLumenMeshSDFGridParameters, )
    SHADER_PARAMETER_STRUCT_INCLUDE(FLumenMeshSDFTracingParameters, TracingParameters)
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint>, NumGridCulledMeshSDFObjects)
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint>, GridCulledMeshSDFObjectStartOffsetArray)
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint>, GridCulledMeshSDFObjectIndicesArray)
    SHADER_PARAMETER(uint32, CardGridPixelSizeShift)
    SHADER_PARAMETER(FVector3f, CardGridZParams)
    SHADER_PARAMETER(FIntVector, CullGridSize)
    // Heightfield data
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint>, NumCulledHeightfieldObjects)
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint>, CulledHeightfieldObjectIndexBuffer)
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint>, NumGridCulledHeightfieldObjects)
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint>, GridCulledHeightfieldObjectStartOffsetArray)
    SHADER_PARAMETER_RDG_BUFFER_SRV(Buffer<uint>, GridCulledHeightfieldObjectIndicesArray)
END_SHADER_PARAMETER_STRUCT()
 
BEGIN_SHADER_PARAMETER_STRUCT(FLumenIndirectTracingParameters, )
    SHADER_PARAMETER(float, StepFactor)
    SHADER_PARAMETER(float, CardTraceEndDistanceFromCamera)
    SHADER_PARAMETER(float, DiffuseConeHalfAngle)
    SHADER_PARAMETER(float, TanDiffuseConeHalfAngle)
    SHADER_PARAMETER(float, MinSampleRadius)
    SHADER_PARAMETER(float, MinTraceDistance)
    SHADER_PARAMETER(float, MaxTraceDistance)
    SHADER_PARAMETER(float, MaxMeshSDFTraceDistance)
    SHADER_PARAMETER(float, SurfaceBias)
    SHADER_PARAMETER(float, CardInterpolateInfluenceRadius)
    SHADER_PARAMETER(float, SpecularFromDiffuseRoughnessStart)
    SHADER_PARAMETER(float, SpecularFromDiffuseRoughnessEnd)
    SHADER_PARAMETER(int32, HeightfieldMaxTracingSteps)
END_SHADER_PARAMETER_STRUCT()
 
BEGIN_SHADER_PARAMETER_STRUCT(FLumenDiffuseTracingParameters, )
    SHADER_PARAMETER_STRUCT_INCLUDE(HybridIndirectLighting::FCommonParameters, CommonDiffuseParameters)
    SHADER_PARAMETER_STRUCT_INCLUDE(FLumenIndirectTracingParameters, IndirectTracingParameters)
    SHADER_PARAMETER(float, SampleWeight)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, DownsampledDepth)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, DownsampledNormal)
END_SHADER_PARAMETER_STRUCT()
 
BEGIN_SHADER_PARAMETER_STRUCT(FLumenHZBScreenTraceParameters, )
    SHADER_PARAMETER_RDG_TEXTURE_SRV(Texture2D, PrevSceneColorTexture)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D, HistorySceneDepth)
    SHADER_PARAMETER_STRUCT_INCLUDE(FHZBParameters, HZBParameters)
    SHADER_PARAMETER(FVector2f, PrevSceneColorBilinearUVMin)
    SHADER_PARAMETER(FVector2f, PrevSceneColorBilinearUVMax)
    SHADER_PARAMETER(FVector4f, PrevScreenPositionScaleBias)
    SHADER_PARAMETER(FVector4f, PrevScreenPositionScaleBiasForDepth)
    SHADER_PARAMETER(float, PrevSceneColorPreExposureCorrection)
END_SHADER_PARAMETER_STRUCT()
 
BEGIN_SHADER_PARAMETER_STRUCT(FLumenScreenSpaceBentNormalParameters, )
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D<UNORM float>, ShortRangeAOTexture)
    SHADER_PARAMETER_RDG_TEXTURE(Texture2D<float3>, ShortRangeGITexture)
    SHADER_PARAMETER(FIntPoint, ShortRangeAOViewMin)
    SHADER_PARAMETER(FIntPoint, ShortRangeAOViewSize)
    SHADER_PARAMETER(uint32, ShortRangeAOMode)
END_SHADER_PARAMETER_STRUCT()
 
extern void CullHeightfieldObjectsForView(
    FRDGBuilder& GraphBuilder,
    const FScene* Scene,
    const FViewInfo& View,
    const FLumenSceneFrameTemporaries& FrameTemporaries,
    float MaxMeshSDFInfluenceRadius,
    float CardTraceEndDistanceFromCamera,
    FRDGBufferRef& NumCulledObjects,
    FRDGBufferRef& CulledObjectIndexBuffer);
 
extern void CullMeshObjectsToViewGrid(
    const FViewInfo& View,
    const FScene* Scene,
    const FLumenSceneFrameTemporaries& FrameTemporaries,
    float MaxMeshSDFInfluenceRadius,
    float CardTraceEndDistanceFromCamera,
    int32 GridPixelsPerCellXY,
    int32 GridSizeZ,
    FVector ZParams,
    FRDGBuilder& GraphBuilder,
    FLumenMeshSDFGridParameters& OutGridParameters,
    ERDGPassFlags ComputePassFlags = ERDGPassFlags::Compute);
 
extern void CullForCardTracing(
    FRDGBuilder& GraphBuilder,
    const FScene* Scene,
    const FViewInfo& View,
    const FLumenSceneFrameTemporaries& FrameTemporaries,
    const FLumenIndirectTracingParameters& IndirectTracingParameters,
    FLumenMeshSDFGridParameters& MeshSDFGridParameters,
    ERDGPassFlags ComputePassFlags = ERDGPassFlags::Compute);
 
extern void SetupLumenDiffuseTracingParameters(float MaxTraceDistance, float OrthoMaxDimension, FLumenIndirectTracingParameters& OutParameters);
extern void SetupLumenDiffuseTracingParametersForProbe(float MaxTraceDistance, float OrthoMaxDimension, FLumenIndirectTracingParameters& OutParameters, float DiffuseConeHalfAngle);
 
extern void SetupLumenDiffuseTracingParameters(const FViewInfo& View, FLumenIndirectTracingParameters& OutParameters);
extern void SetupLumenDiffuseTracingParametersForProbe(const FViewInfo& View, FLumenIndirectTracingParameters& OutParameters, float DiffuseConeAngle);
 
extern void SetupLumenMeshSDFTracingParameters(FRDGBuilder& GraphBuilder, const FScene* Scene, const FViewInfo& View,FLumenMeshSDFTracingParameters& OutParameters);
 
extern FLumenHZBScreenTraceParameters SetupHZBScreenTraceParameters(
    FRDGBuilder& GraphBuilder, 
    const FViewInfo& View,
    const FSceneTextures& SceneTextures);
 
extern int32 GLumenIrradianceFieldGather;
 
namespace LumenIrradianceFieldGather
{
    LumenRadianceCache::FRadianceCacheInputs SetupRadianceCacheInputs();
}
 
namespace LumenDiffuseIndirect
{
    bool IsAllowed();
    bool UseAsyncCompute(const FViewFamilyInfo& ViewFamily, EDiffuseIndirectMethod DiffuseIndirectMethod);
}