130 lines
7.5 KiB
HLSL
130 lines
7.5 KiB
HLSL
// Copyright Epic Games, Inc. All Rights Reserved.
|
|
|
|
#pragma once
|
|
|
|
// Check parameters/resources prefixing macro is well defined
|
|
#ifndef HAIR_STRANDS_ATTRIBUTE_ACCESSORS
|
|
#error HAIR_STRANDS_ATTRIBUTE_ACCESSORS needs to be defined
|
|
#endif
|
|
|
|
// Redefine macro for easing reability
|
|
#define PREFIX(Name) HAIR_STRANDS_ATTRIBUTE_ACCESSORS(Name)
|
|
|
|
float2 GetHairStrandsUV(uint InControlPointId, float2 InSegmentUV)
|
|
{
|
|
const float CoordU0 = InternalGetHairStrandsCoordU(PREFIX(PositionBuffer), InControlPointId, PREFIX(Radius), PREFIX(RootScale), PREFIX(TipScale));
|
|
const float CoordU1 = InternalGetHairStrandsCoordU(PREFIX(PositionBuffer), InControlPointId+1, PREFIX(Radius), PREFIX(RootScale), PREFIX(TipScale));
|
|
|
|
float2 Out;
|
|
Out.x = lerp(CoordU0, CoordU1, InSegmentUV.x);
|
|
Out.y = InSegmentUV.y;
|
|
return Out;
|
|
}
|
|
float2 GetHairStrandsDimensions(uint InControlPointId, float InSegmentU)
|
|
{
|
|
const float CurveLength = UnpackHairLength(InternalGetHairStrandsAttributesPerCurve(InControlPointId, HAIR_CURVE_ATTRIBUTE_OFFSET_LENGTH(PREFIX(CurveAttributeOffsets)), HAIR_CURVE_ATTRIBUTE_STRIDE_LENGTH, PREFIX(CurveAttributeBuffer), PREFIX(PointToCurveBuffer), PREFIX(CurveAttributeIndexToChunkDivAsShift), PREFIX(CurveAttributeChunkElementCount), PREFIX(CurveAttributeChunkStrideInBytes)));
|
|
|
|
const float CoordU0 = InternalGetHairStrandsCoordU(PREFIX(PositionBuffer), InControlPointId, PREFIX(Radius), PREFIX(RootScale), PREFIX(TipScale));
|
|
const float CoordU1 = InternalGetHairStrandsCoordU(PREFIX(PositionBuffer), InControlPointId+1, PREFIX(Radius), PREFIX(RootScale), PREFIX(TipScale));
|
|
const float CoordU = lerp(CoordU0, CoordU1, InSegmentU);
|
|
|
|
const float Radius0 = InternalGetHairStrandsWorldRadius(PREFIX(PositionBuffer), InControlPointId, PREFIX(Radius), PREFIX(RootScale), PREFIX(TipScale));
|
|
const float Radius1 = InternalGetHairStrandsWorldRadius(PREFIX(PositionBuffer), InControlPointId+1, PREFIX(Radius), PREFIX(RootScale), PREFIX(TipScale));
|
|
const float Radius = lerp(Radius0, Radius1, InSegmentU);
|
|
|
|
return float2(CurveLength * CoordU, Radius);
|
|
}
|
|
float2 GetHairStrandsRootUV(uint InControlPointId)
|
|
{
|
|
const uint RootUVOffset = HAIR_CURVE_ATTRIBUTE_OFFSET_ROOTUV(PREFIX(CurveAttributeOffsets));
|
|
if (IsAttributeValid(RootUVOffset))
|
|
{
|
|
return UnpackHairRootUV(InternalGetHairStrandsAttributesPerCurve(InControlPointId, RootUVOffset, HAIR_CURVE_ATTRIBUTE_STRIDE_ROOTUV, PREFIX(CurveAttributeBuffer), PREFIX(PointToCurveBuffer), PREFIX(CurveAttributeIndexToChunkDivAsShift), PREFIX(CurveAttributeChunkElementCount), PREFIX(CurveAttributeChunkStrideInBytes)));
|
|
}
|
|
else
|
|
{
|
|
return 0;
|
|
}
|
|
}
|
|
float GetHairStrandsSeed(uint InControlPointId)
|
|
{
|
|
return UnpackHairSeed(InternalGetHairStrandsAttributesPerCurve(InControlPointId, HAIR_CURVE_ATTRIBUTE_OFFSET_SEED(PREFIX(CurveAttributeOffsets)), HAIR_CURVE_ATTRIBUTE_STRIDE_SEED, PREFIX(CurveAttributeBuffer), PREFIX(PointToCurveBuffer), PREFIX(CurveAttributeIndexToChunkDivAsShift), PREFIX(CurveAttributeChunkElementCount), PREFIX(CurveAttributeChunkStrideInBytes)));
|
|
}
|
|
uint3 GetHairStrandsClumpID(uint InControlPointId)
|
|
{
|
|
const uint ClumpIdOffset = HAIR_CURVE_ATTRIBUTE_OFFSET_CLUMPID(PREFIX(CurveAttributeOffsets));
|
|
const uint ClumpId3Offset = HAIR_CURVE_ATTRIBUTE_OFFSET_CLUMPID3(PREFIX(CurveAttributeOffsets));
|
|
if (IsAttributeValid(ClumpIdOffset))
|
|
{
|
|
return UnpackHairClumpID(InternalGetHairStrandsAttributesPerCurve(InControlPointId, ClumpIdOffset, HAIR_CURVE_ATTRIBUTE_STRIDE_CLUMPID, PREFIX(CurveAttributeBuffer), PREFIX(PointToCurveBuffer), PREFIX(CurveAttributeIndexToChunkDivAsShift), PREFIX(CurveAttributeChunkElementCount), PREFIX(CurveAttributeChunkStrideInBytes)));
|
|
}
|
|
else if (IsAttributeValid(ClumpId3Offset))
|
|
{
|
|
return UnpackHairClumpID(InternalGetHairStrandsAttributesPerCurve64(InControlPointId, ClumpId3Offset, HAIR_CURVE_ATTRIBUTE_STRIDE_CLUMPID3, PREFIX(CurveAttributeBuffer), PREFIX(PointToCurveBuffer), PREFIX(CurveAttributeIndexToChunkDivAsShift), PREFIX(CurveAttributeChunkElementCount), PREFIX(CurveAttributeChunkStrideInBytes)));
|
|
}
|
|
else
|
|
{
|
|
return 0;
|
|
}
|
|
}
|
|
float3 GetHairStrandsColor(uint InControlPointId, float InSegmentU)
|
|
{
|
|
const uint ColorOffset = HAIR_POINT_ATTRIBUTE_OFFSET_COLOR(PREFIX(PointAttributeOffsets));
|
|
if (IsAttributeValid(ColorOffset))
|
|
{
|
|
const float3 Color0 = UnpackHairColor(InternalGetHairStrandsAttributesPerVertex(InControlPointId, ColorOffset, HAIR_POINT_ATTRIBUTE_STRIDE_COLOR, PREFIX(PointAttributeBuffer), PREFIX(PointAttributeIndexToChunkDivAsShift), PREFIX(PointAttributeChunkElementCount), PREFIX(PointAttributeChunkStrideInBytes)));
|
|
const float3 Color1 = UnpackHairColor(InternalGetHairStrandsAttributesPerVertex(InControlPointId+1, ColorOffset, HAIR_POINT_ATTRIBUTE_STRIDE_COLOR, PREFIX(PointAttributeBuffer), PREFIX(PointAttributeIndexToChunkDivAsShift), PREFIX(PointAttributeChunkElementCount), PREFIX(PointAttributeChunkStrideInBytes)));
|
|
return lerp(Color0, Color1, InSegmentU);
|
|
}
|
|
else
|
|
{
|
|
return 0;
|
|
}
|
|
}
|
|
float GetHairStrandsRoughness(uint InControlPointId, float InSegmentU)
|
|
{
|
|
const uint RoughnessOffset = HAIR_POINT_ATTRIBUTE_OFFSET_ROUGHNESS(PREFIX(PointAttributeOffsets));
|
|
if (IsAttributeValid(RoughnessOffset))
|
|
{
|
|
const float Roughness0 = UnpackHairRoughness(InternalGetHairStrandsAttributesPerVertex(InControlPointId, RoughnessOffset, HAIR_POINT_ATTRIBUTE_STRIDE_ROUGHNESS, PREFIX(PointAttributeBuffer), PREFIX(PointAttributeIndexToChunkDivAsShift), PREFIX(PointAttributeChunkElementCount), PREFIX(PointAttributeChunkStrideInBytes)));
|
|
const float Roughness1 = UnpackHairRoughness(InternalGetHairStrandsAttributesPerVertex(InControlPointId+1, RoughnessOffset, HAIR_POINT_ATTRIBUTE_STRIDE_ROUGHNESS, PREFIX(PointAttributeBuffer), PREFIX(PointAttributeIndexToChunkDivAsShift), PREFIX(PointAttributeChunkElementCount), PREFIX(PointAttributeChunkStrideInBytes)));
|
|
return lerp(Roughness0, Roughness1, InSegmentU);
|
|
}
|
|
else
|
|
{
|
|
return 0;
|
|
}
|
|
}
|
|
float GetHairStrandsAO(uint InControlPointId, float InSegmentU)
|
|
{
|
|
const uint AoOffset = HAIR_POINT_ATTRIBUTE_OFFSET_AO(PREFIX(PointAttributeOffsets));
|
|
if (IsAttributeValid(AoOffset))
|
|
{
|
|
const float AO0 = UnpackHairAO(InternalGetHairStrandsAttributesPerVertex(InControlPointId, AoOffset, HAIR_POINT_ATTRIBUTE_STRIDE_AO, PREFIX(PointAttributeBuffer), PREFIX(PointAttributeIndexToChunkDivAsShift), PREFIX(PointAttributeChunkElementCount), PREFIX(PointAttributeChunkStrideInBytes)));
|
|
const float AO1 = UnpackHairAO(InternalGetHairStrandsAttributesPerVertex(InControlPointId+1, AoOffset, HAIR_POINT_ATTRIBUTE_STRIDE_AO, PREFIX(PointAttributeBuffer), PREFIX(PointAttributeIndexToChunkDivAsShift), PREFIX(PointAttributeChunkElementCount), PREFIX(PointAttributeChunkStrideInBytes)));
|
|
return lerp(AO0, AO1, InSegmentU);
|
|
}
|
|
else
|
|
{
|
|
return 1.f;
|
|
}
|
|
}
|
|
float GetHairStrandsDepth()
|
|
{
|
|
return 0.f;
|
|
}
|
|
float GetHairStrandsCoverage()
|
|
{
|
|
return 1;
|
|
}
|
|
float GetHairStrandsGroupIndex()
|
|
{
|
|
return PREFIX(GroupIndex);
|
|
}
|
|
bool HasHairStrandsRootUV() { return IsAttributeValid(HAIR_CURVE_ATTRIBUTE_OFFSET_ROOTUV(PREFIX(CurveAttributeOffsets))); }
|
|
bool HasHairStrandsClumpId() { return IsAttributeValid(HAIR_CURVE_ATTRIBUTE_OFFSET_CLUMPID(PREFIX(CurveAttributeOffsets))); }
|
|
bool HasHairStrandsClumpId3() { return IsAttributeValid(HAIR_CURVE_ATTRIBUTE_OFFSET_CLUMPID3(PREFIX(CurveAttributeOffsets))); }
|
|
bool HasHairStrandsColor() { return IsAttributeValid(HAIR_POINT_ATTRIBUTE_OFFSET_COLOR(PREFIX(PointAttributeOffsets))); }
|
|
bool HasHairStrandsRoughness() { return IsAttributeValid(HAIR_POINT_ATTRIBUTE_OFFSET_ROUGHNESS(PREFIX(PointAttributeOffsets))); }
|
|
bool HasHairStrandsAO() { return IsAttributeValid(HAIR_POINT_ATTRIBUTE_OFFSET_AO(PREFIX(PointAttributeOffsets))); }
|