Files
UnrealEngine/Engine/Shaders/Private/TranslucentLightingShaders.usf
2025-05-18 13:04:45 +08:00

395 lines
14 KiB
HLSL

// Copyright Epic Games, Inc. All Rights Reserved.
/**
* TranslucentLightingShaders.usf: Shaders for calculating lighting in a volume to use on translucency
*/
#include "Common.ush"
#include "SHCommon.ush"
#include "SceneTexturesCommon.ush"
#include "BlueNoise.ush"
#include "ComputeShaderUtils.ush"
struct FWriteToSliceVertexOutput
{
FScreenVertexOutput Vertex;
#if USING_VERTEX_SHADER_LAYER
uint LayerIndex : SV_RenderTargetArrayIndex;
#else
uint LayerIndex : TEXCOORD1;
#endif
};
/** Z index of the minimum slice in the range. */
int MinZ;
float4 UVScaleBias;
uint VolumeCascadeIndex;
/** Vertex shader that writes to a range of slices of a volume texture. */
void WriteToSliceMainVS(
float2 InPosition : ATTRIBUTE0,
float2 InUV : ATTRIBUTE1,
uint LayerIndex : SV_InstanceID,
out FWriteToSliceVertexOutput Output
)
{
Output.Vertex.Position = float4( InPosition, 0, 1 );
// Remap UVs based on the subregion of the volume texture being rendered to
Output.Vertex.UV = InUV * UVScaleBias.xy + UVScaleBias.zw;
Output.LayerIndex = LayerIndex + MinZ;
}
/** Encodes HDR linear scene color for storage in the 8 bit light attenuation texture. */
MaterialFloat3 EncodeSceneColorForMaterialNode(MaterialFloat3 LinearSceneColor)
{
// Preserving a range from [0, 10]
// Remap values to get more bits of precision in the darks
return pow(LinearSceneColor * .1f, .25f);
}
#if FEATURE_LEVEL >= FEATURE_LEVEL_SM5
Texture2D SceneColorTexture;
void CopySceneColorMain(FScreenVertexOutput Input, out float4 OutColor : SV_Target0)
{
float4 LinearColor = Texture2DSample(SceneColorTexture, GlobalPointClampedSampler, Input.UV);
OutColor = float4(EncodeSceneColorForMaterialNode(LinearColor.rgb), LinearColor.a);
}
/** Geometry shader that writes to a range of slices of a volume texture. */
[maxvertexcount(3)]
void WriteToSliceMainGS(triangle FWriteToSliceVertexOutput Input[3], inout TriangleStream<FWriteToSliceGeometryOutput> OutStream)
{
FWriteToSliceGeometryOutput Vertex0;
Vertex0.Vertex = Input[0].Vertex;
Vertex0.LayerIndex = Input[0].LayerIndex;
FWriteToSliceGeometryOutput Vertex1;
Vertex1.Vertex = Input[1].Vertex;
Vertex1.LayerIndex = Input[1].LayerIndex;
FWriteToSliceGeometryOutput Vertex2;
Vertex2.Vertex = Input[2].Vertex;
Vertex2.LayerIndex = Input[2].LayerIndex;
OutStream.Append(Vertex0);
OutStream.Append(Vertex1);
OutStream.Append(Vertex2);
}
float3 GetTranslatedWorldPositionFromVolumeCoord(uint3 VolumeCoord, uint CascadeIndex)
{
return View.TranslucencyLightingVolumeMin[CascadeIndex].xyz + (VolumeCoord + .5f) * View.TranslucencyLightingVolumeInvSize[CascadeIndex].w;
}
float3 GetTranslatedWorldPositionFromVolumeCoord(uint3 VolumeCoord)
{
return View.TranslucencyLightingVolumeMin[VolumeCascadeIndex].xyz + (VolumeCoord + .5f) * View.TranslucencyLightingVolumeInvSize[VolumeCascadeIndex].w;
}
#ifdef GatherMarkedVoxelsCS
Texture3D<uint> VolumeMarkTexture;
uint3 VolumeSize;
RWStructuredBuffer<uint> RWVoxelAllocator;
RWStructuredBuffer<uint> RWVoxelData;
[numthreads(THREADGROUP_SIZE_X, THREADGROUP_SIZE_Y, THREADGROUP_SIZE_Z)]
void GatherMarkedVoxelsCS(uint3 DispatchThreadId : SV_DispatchThreadID)
{
uint3 VolumeCoord = DispatchThreadId.xyz;
if (any(VolumeCoord >= VolumeSize))
{
return;
}
if (VolumeMarkTexture[VolumeCoord] == 0)
{
return;
}
uint PackedVoxelIndex;
InterlockedAdd(RWVoxelAllocator[0], 1, PackedVoxelIndex);
RWVoxelData[PackedVoxelIndex] = (VolumeCoord.x) | (VolumeCoord.y << 10) | (VolumeCoord.z << 20);
}
#endif // GatherMarkedVoxelsCS
#ifdef InitIndirectArgsCS
RWBuffer<uint> RWIndirectArgs;
StructuredBuffer<uint> VoxelAllocator;
[numthreads(1, 1, 1)]
void InitIndirectArgsCS(uint3 DispatchThreadId : SV_DispatchThreadID)
{
// Need to span the launch size across X,Y,Z so any single dimension does not exceed the 64k
// limit as per https://microsoft.github.io/DirectX-Specs/d3d/MeshShader.html#dispatchmesh-api
// The product of X*Y*Z can be 2^22, so we convert 1D->3D->1D to work around this limitation.
const uint DimensionLimit = (1u << 16u) - 1u;
WriteDispatchIndirectArgs(RWIndirectArgs, 0, GetGroupCountWrapped(DivideAndRoundUp(VoxelAllocator[0], THREADGROUP_SIZE), DimensionLimit.xx));
}
#endif
#ifdef FilterTranslucentVolumeCS
/** Filter pass ouputs. */
RWTexture3D<float4> RWTranslucencyLightingVolumeAmbient;
RWTexture3D<float4> RWTranslucencyLightingVolumeDirectional;
/** Filter pass inputs. */
Texture3D TranslucencyLightingVolumeAmbient;
SamplerState TranslucencyLightingVolumeAmbientSampler;
Texture3D TranslucencyLightingVolumeDirectional;
SamplerState TranslucencyLightingVolumeDirectionalSampler;
Texture3D HistoryAmbient;
Texture3D HistoryDirectional;
SamplerState HistoryAmbientSampler;
SamplerState HistoryDirectionalSampler;
Texture3D<uint> HistoryMark;
uint3 VolumeSize;
float TexelSize;
float4 PrevTranslucencyLightingVolumeMin;
float4 PrevTranslucencyLightingVolumeInvSize;
float3 HistoryTextureBilinearUVMin;
float3 HistoryTextureBilinearUVMax;
float HistoryWeight;
float GetBorderLerpFactor(float3 UVW)
{
// Larger values result in a shorter transition distance
float TransitionScale = 10;
// Rescale the UVs to make the fade go to 0 before the edge of the volume
float3 FadeUVs = UVW * (1 + 4 * View.TranslucencyLightingVolumeMin[VolumeCascadeIndex].w) - 2 * View.TranslucencyLightingVolumeMin[VolumeCascadeIndex].w;
// Setup a 3d lerp factor going to 0 near the edge of the outer volume
float3 LerpFactors = saturate((.5f - abs(FadeUVs - .5f)) * TransitionScale);
float FinalLerpFactor = LerpFactors.x * LerpFactors.y * LerpFactors.z;
//FinalLerpFactor = 1.0f;
return FinalLerpFactor;
}
/** Filters the volume lighting to reduce aliasing. */
[numthreads(THREADGROUP_SIZE_X, THREADGROUP_SIZE_Y, THREADGROUP_SIZE_Z)]
void FilterTranslucentVolumeCS(uint3 DispatchThreadId : SV_DispatchThreadID)
{
const uint3 VolumeCoord = DispatchThreadId.xyz;
if (any(VolumeCoord >= VolumeSize))
{
return;
}
const float3 VolumeUV = (VolumeCoord + 0.5f) * TexelSize;
float4 TextureValue0 = 0;
float4 TextureValue1 = 0;
#define USE_FILTER 1
#if USE_FILTER
#if USE_TEMPORAL_REPROJECTION
TextureValue0 = TranslucencyLightingVolumeAmbient[VolumeCoord];
TextureValue1 = TranslucencyLightingVolumeDirectional[VolumeCoord];
float3 TranslatedWorldPosition = GetTranslatedWorldPositionFromVolumeCoord(VolumeCoord);
int3 HistoryCoord = (TranslatedWorldPosition - PrevTranslucencyLightingVolumeMin.xyz) / PrevTranslucencyLightingVolumeInvSize.w;
float4 HistoryTextureValue0 = HistoryAmbient[HistoryCoord];
float4 HistoryTextureValue1 = HistoryDirectional[HistoryCoord];
float HistoryAlpha = HistoryWeight;
if (any(HistoryCoord < 0) || any(HistoryCoord >= VolumeSize))
{
HistoryAlpha = 0;
}
#if CHECK_HISTORY_MARK
// don't use history if it was not computed
if (HistoryMark[HistoryCoord] == 0)
{
HistoryAlpha = 0;
}
#endif
if (VolumeCascadeIndex == 1)
{
// fade out at border to prevent issues with usage of clamped sampler during shading passes
HistoryAlpha *= GetBorderLerpFactor(VolumeUV);
}
TextureValue0 = lerp(TextureValue0, HistoryTextureValue0, HistoryAlpha);
TextureValue1 = lerp(TextureValue1, HistoryTextureValue1, HistoryAlpha);
float InvWeight = 1;
#else // !USE_TEMPORAL_REPROJECTION
// Use trilinear filtering to filter neighbors to the current voxel with minimal texture fetches
TextureValue0 += Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV + .5f * TexelSize * float3(1, 1, 1));
TextureValue0 += Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV + .5f * TexelSize * float3(-1, 1, 1));
TextureValue0 += Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV + .5f * TexelSize * float3(1, -1, 1));
TextureValue0 += Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV + .5f * TexelSize * float3(-1, -1, 1));
TextureValue0 += Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV + .5f * TexelSize * float3(1, 1, -1));
TextureValue0 += Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV + .5f * TexelSize * float3(-1, 1, -1));
TextureValue0 += Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV + .5f * TexelSize * float3(1, -1, -1));
TextureValue0 += Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV + .5f * TexelSize * float3(-1, -1, -1));
TextureValue1 += Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV + .5f * TexelSize * float3(1, 1, 1));
TextureValue1 += Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV + .5f * TexelSize * float3(-1, 1, 1));
TextureValue1 += Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV + .5f * TexelSize * float3(1, -1, 1));
TextureValue1 += Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV + .5f * TexelSize * float3(-1, -1, 1));
TextureValue1 += Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV + .5f * TexelSize * float3(1, 1, -1));
TextureValue1 += Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV + .5f * TexelSize * float3(-1, 1, -1));
TextureValue1 += Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV + .5f * TexelSize * float3(1, -1, -1));
TextureValue1 += Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV + .5f * TexelSize * float3(-1, -1, -1));
float InvWeight = 1.0f / 8;
#endif // !USE_TEMPORAL_REPROJECTION
#else
TextureValue0 = Texture3DSample(TranslucencyLightingVolumeAmbient, TranslucencyLightingVolumeAmbientSampler, VolumeUV);
TextureValue1 = Texture3DSample(TranslucencyLightingVolumeDirectional, TranslucencyLightingVolumeDirectionalSampler, VolumeUV);
float InvWeight = 1;
#endif
RWTranslucencyLightingVolumeAmbient[DispatchThreadId] = TextureValue0 * InvWeight;
RWTranslucencyLightingVolumeDirectional[DispatchThreadId] = TextureValue1 * InvWeight;
}
#endif // FilterTranslucentVolumeCS
#include "CubemapCommon.ush"
/** Add AmbientCubemap color to the volume. */
void InjectAmbientCubemapMainPS(
FWriteToSliceGeometryOutput Input,
out float4 OutColor : SV_Target0
)
{
// can be optimized by moving it into the vertex/geometry shader
OutColor = float4(ComputeAmbientCubemapAvgColor(), 0);
}
#endif // FEATURE_LEVEL
#ifdef DebugTranslucencyLightingVolumeCS
#include "/Engine/Private/ShaderPrint.ush"
void PrintTranslucencyVolume(inout FShaderPrintContext Context, float3 Min, float3 Max, float4 Color)
{
float3 C000 = float3(Min.x, Min.y, Min.z);
float3 C001 = float3(Min.x, Min.y, Max.z);
float3 C010 = float3(Min.x, Max.y, Min.z);
float3 C011 = float3(Min.x, Max.y, Max.z);
float3 C100 = float3(Max.x, Min.y, Min.z);
float3 C101 = float3(Max.x, Min.y, Max.z);
float3 C110 = float3(Max.x, Max.y, Min.z);
float3 C111 = float3(Max.x, Max.y, Max.z);
AddLineTWS(Context, C000, C001, Color);
AddLineTWS(Context, C001, C011, Color);
AddLineTWS(Context, C011, C010, Color);
AddLineTWS(Context, C010, C000, Color);
AddLineTWS(Context, C100, C101, Color);
AddLineTWS(Context, C101, C111, Color);
AddLineTWS(Context, C111, C110, Color);
AddLineTWS(Context, C110, C100, Color);
AddLineTWS(Context, C001, C101, Color);
AddLineTWS(Context, C100, C000, Color);
AddLineTWS(Context, C011, C111, Color);
AddLineTWS(Context, C110, C010, Color);
}
Texture3D<uint> InnerVolumeMarkTexture;
Texture3D<uint> OuterVolumeMarkTexture;
StructuredBuffer<uint> VoxelAllocator;
[numthreads(THREADGROUP_SIZE, THREADGROUP_SIZE, THREADGROUP_SIZE)]
void DebugTranslucencyLightingVolumeCS(
uint3 GroupId : SV_GroupID,
uint3 DispatchThreadId : SV_DispatchThreadID,
uint3 GroupThreadId : SV_GroupThreadID)
{
if (all(DispatchThreadId == 0))
{
FShaderPrintContext Context = InitShaderPrintContext(true, uint2(50, 50));
const float3 VolMin0 = View.TranslucencyLightingVolumeMin[0].xyz;
const float3 VolMin1 = View.TranslucencyLightingVolumeMin[1].xyz;
const float3 VolSize0 = 1.0f / View.TranslucencyLightingVolumeInvSize[0].xyz;
const float3 VolSize1 = 1.0f / View.TranslucencyLightingVolumeInvSize[1].xyz;
const float3 VolMax0 = VolMin0 + VolSize0;
const float3 VolMax1 = VolMin1 + VolSize1;
PrintTranslucencyVolume(Context, VolMin0, VolMax0, float4(0, 1, 0, 1));
PrintTranslucencyVolume(Context, VolMin1, VolMax1, float4(1, 1, 0, 1));
Print(Context, TEXT("Translucency Light Volume0 Size = "), FontWhite);
Print(Context, VolSize0.x, FontYellow, 10, 1);
Print(Context, TEXT(", "), FontWhite);
Print(Context, VolSize0.y, FontYellow, 10, 1);
Print(Context, TEXT(", "), FontWhite);
Print(Context, VolSize0.y, FontYellow, 10, 1);
Newline(Context);
Print(Context, TEXT("Translucency Light Volume1 Size = "), FontWhite);
Print(Context, VolSize1.x, FontYellow, 10, 1);
Print(Context, TEXT(", "), FontWhite);
Print(Context, VolSize1.y, FontYellow, 10, 1);
Print(Context, TEXT(", "), FontWhite);
Print(Context, VolSize1.y, FontYellow, 10, 1);
}
// draw marked voxels
if (InnerVolumeMarkTexture[DispatchThreadId] > 0)
{
FShaderPrintContext Context = InitShaderPrintContext(true, uint2(50, 50));
const float3 TranslatedWorldPosition = GetTranslatedWorldPositionFromVolumeCoord(DispatchThreadId, 0);
const float3 VoxelExtent = View.TranslucencyLightingVolumeInvSize[0].w / 2;
PrintTranslucencyVolume(Context, TranslatedWorldPosition - VoxelExtent, TranslatedWorldPosition + VoxelExtent, float4(0, 1, 0, 1));
}
if (OuterVolumeMarkTexture[DispatchThreadId] > 0)
{
FShaderPrintContext Context = InitShaderPrintContext(true, uint2(50, 50));
const float3 TranslatedWorldPosition = GetTranslatedWorldPositionFromVolumeCoord(DispatchThreadId, 1);
const float3 VoxelExtent = View.TranslucencyLightingVolumeInvSize[1].w / 2;
PrintTranslucencyVolume(Context, TranslatedWorldPosition - VoxelExtent, TranslatedWorldPosition + VoxelExtent, float4(1, 1, 0, 1));
}
}
#endif // DebugTranslucencyLightingVolumeCS