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99 行
4.0 KiB
99 行
4.0 KiB
#include "SubsurfaceScatteringSettings.cs.hlsl"
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#include "CoreRP/ShaderLibrary/Packing.hlsl"
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#include "CommonSubsurfaceScattering.hlsl"
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// Subsurface scattering constant
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#define SSS_WRAP_ANGLE (PI/12) // 15 degrees
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#define SSS_WRAP_LIGHT cos(PI/2 - SSS_WRAP_ANGLE)
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CBUFFER_START(UnitySSSParameters)
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// Warning: Unity is not able to losslessly transfer integers larger than 2^24 to the shader system.
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// Therefore, we bitcast uint to float in C#, and bitcast back to uint in the shader.
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uint _EnableSSSAndTransmission; // Globally toggles subsurface and transmission scattering on/off
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float _TexturingModeFlags; // 1 bit/profile; 0 = PreAndPostScatter, 1 = PostScatter
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float _TransmissionFlags; // 2 bit/profile; 0 = inf. thick, 1 = thin, 2 = regular
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// Old SSS Model >>>
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uint _UseDisneySSS;
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float4 _HalfRcpVariancesAndWeights[SSS_N_PROFILES][2]; // 2x Gaussians in RGB, A is interpolation weights
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// <<< Old SSS Model
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// Use float4 to avoid any packing issue between compute and pixel shaders
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float4 _ThicknessRemaps[SSS_N_PROFILES]; // R: start, G = end - start, BA unused
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float4 _ShapeParams[SSS_N_PROFILES]; // RGB = S = 1 / D, A = filter radius
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float4 _TransmissionTintsAndFresnel0[SSS_N_PROFILES]; // RGB = 1/4 * color, A = fresnel0
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float4 _WorldScales[SSS_N_PROFILES]; // X = meters per world unit; Y = world units per meter
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CBUFFER_END
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// ----------------------------------------------------------------------------
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// helper functions
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// ----------------------------------------------------------------------------
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// Returns the modified albedo (diffuse color) for materials with subsurface scattering.
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// Ref: Advanced Techniques for Realistic Real-Time Skin Rendering.
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float3 ApplyDiffuseTexturingMode(float3 color, int subsurfaceProfile)
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{
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#if defined(SHADERPASS) && (SHADERPASS == SHADERPASS_SUBSURFACE_SCATTERING)
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// If the SSS pass is executed, we know we have SSS enabled.
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bool enableSssAndTransmission = true;
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#else
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bool enableSssAndTransmission = _EnableSSSAndTransmission != 0;
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#endif
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if (enableSssAndTransmission)
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{
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bool performPostScatterTexturing = IsBitSet(asuint(_TexturingModeFlags), subsurfaceProfile);
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if (performPostScatterTexturing)
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{
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// Post-scatter texturing mode: the albedo is only applied during the SSS pass.
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#if !defined(SHADERPASS) || (SHADERPASS != SHADERPASS_SUBSURFACE_SCATTERING)
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color = float3(1, 1, 1);
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#endif
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}
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else
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{
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// Pre- and post- scatter texturing mode.
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color = sqrt(color);
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}
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}
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return color;
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}
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// ----------------------------------------------------------------------------
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// Encoding/decoding SSS buffer functions
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// ----------------------------------------------------------------------------
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struct SSSData
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{
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float3 diffuseColor;
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float subsurfaceRadius;
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int subsurfaceProfile;
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};
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#define SSSBufferType0 float4
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// SSSBuffer texture declaration
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TEXTURE2D(_SSSBufferTexture0);
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void EncodeIntoSSSBuffer(SSSData sssData, uint2 positionSS, out SSSBufferType0 outSSSBuffer0)
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{
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outSSSBuffer0 = float4(sssData.diffuseColor, PackFloatInt8bit(sssData.subsurfaceRadius, sssData.subsurfaceProfile, 16.0));
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}
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void DecodeFromSSSBuffer(float4 sssBuffer, uint2 positionSS, out SSSData sssData)
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{
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sssData.diffuseColor = sssBuffer.rgb;
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UnpackFloatInt8bit(sssBuffer.a, 16.0, sssData.subsurfaceRadius, sssData.subsurfaceProfile);
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}
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void DecodeFromSSSBuffer(uint2 positionSS, out SSSData sssData)
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{
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float4 sssBuffer = LOAD_TEXTURE2D(_SSSBufferTexture0, positionSS);
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DecodeFromSSSBuffer(sssBuffer, positionSS, sssData);
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}
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// OUTPUT_SSSBUFFER start from SV_Target2 as SV_Target0 and SV_Target1 are used for lighting buffer
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#define OUTPUT_SSSBUFFER(NAME) out GBufferType0 MERGE_NAME(NAME, 0) : SV_Target2
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#define ENCODE_INTO_SSSBUFFER(SURFACE_DATA, UNPOSITIONSS, NAME) EncodeIntoSSSBuffer(ConvertSurfaceDataToSSSData(SURFACE_DATA), UNPOSITIONSS, MERGE_NAME(NAME, 0))
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#define DECODE_FROM_SSSBUFFER(UNPOSITIONSS, SSS_DATA) DecodeFromSSSBuffer(UNPOSITIONSS, SSS_DATA)
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