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1794 行
84 KiB
1794 行
84 KiB
//-----------------------------------------------------------------------------
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// SurfaceData and BSDFData
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//-----------------------------------------------------------------------------
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// SurfaceData is define in Lit.cs which generate Lit.cs.hlsl
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#include "Lit.cs.hlsl"
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#include "../SubsurfaceScattering/SubsurfaceScattering.hlsl"
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// Define refraction keyword helpers
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#define HAS_REFRACTION (defined(_REFRACTION_PLANE) || defined(_REFRACTION_SPHERE))
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#if HAS_REFRACTION
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# include "CoreRP/ShaderLibrary/Refraction.hlsl"
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# if defined(_REFRACTION_PLANE)
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# define REFRACTION_MODEL(V, posInputs, bsdfData) RefractionModelPlane(V, posInputs.positionWS, bsdfData.normalWS, bsdfData.ior, bsdfData.thickness)
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# elif defined(_REFRACTION_SPHERE)
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# define REFRACTION_MODEL(V, posInputs, bsdfData) RefractionModelSphere(V, posInputs.positionWS, bsdfData.normalWS, bsdfData.ior, bsdfData.thickness)
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# endif
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#endif
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#define GBufferType0 float4
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#define GBufferType1 float4
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#define GBufferType2 float4
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#define GBufferType3 float4
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// GBuffer texture declaration
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TEXTURE2D(_GBufferTexture0);
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TEXTURE2D(_GBufferTexture1);
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TEXTURE2D(_GBufferTexture2);
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TEXTURE2D(_GBufferTexture3);
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// Reference Lambert diffuse / GGX Specular for IBL and area lights
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#ifdef HAS_LIGHTLOOP // Both reference define below need to be define only if LightLoop is present, else we get a compile error
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// #define LIT_DISPLAY_REFERENCE_AREA
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// #define LIT_DISPLAY_REFERENCE_IBL
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#endif
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// Use Lambert diffuse instead of Disney diffuse
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// #define LIT_DIFFUSE_LAMBERT_BRDF
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#define LIT_USE_GGX_ENERGY_COMPENSATION
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// Rough refraction texture
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// Color pyramid (width, height, lodcount, Unused)
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TEXTURE2D(_GaussianPyramidColorTexture);
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// Depth pyramid (width, height, lodcount, Unused)
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TEXTURE2D(_PyramidDepthTexture);
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CBUFFER_START(UnityGaussianPyramidParameters)
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float4 _GaussianPyramidColorMipSize;
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float4 _PyramidDepthMipSize;
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CBUFFER_END
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// Ambient occlusion texture
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TEXTURE2D(_AmbientOcclusionTexture);
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CBUFFER_START(UnityAmbientOcclusionParameters)
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float4 _AmbientOcclusionParam; // xyz occlusion color, w directLightStrenght
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CBUFFER_END
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// Area light textures
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// TODO: This one should be set into a constant Buffer at pass frequency (with _Screensize)
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TEXTURE2D(_PreIntegratedFGD);
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TEXTURE2D_ARRAY(_LtcData); // We pack the 3 Ltc data inside a texture array
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#define LTC_GGX_MATRIX_INDEX 0 // RGBA
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#define LTC_DISNEY_DIFFUSE_MATRIX_INDEX 1 // RGBA
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#define LTC_MULTI_GGX_FRESNEL_DISNEY_DIFFUSE_INDEX 2 // RGB, A unused
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#define LTC_LUT_SIZE 64
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#define LTC_LUT_SCALE ((LTC_LUT_SIZE - 1) * rcp(LTC_LUT_SIZE))
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#define LTC_LUT_OFFSET (0.5 * rcp(LTC_LUT_SIZE))
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//-----------------------------------------------------------------------------
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// Helper for cheap screen space raycasting
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//-----------------------------------------------------------------------------
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float3 EstimateRaycast(float3 V, PositionInputs posInputs, float3 positionWS, float3 rayWS)
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{
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// For all refraction approximation, to calculate the refracted point in world space,
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// we approximate the scene as a plane (back plane) with normal -V at the depth hit point.
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// (We avoid to raymarch the depth texture to get the refracted point.)
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uint2 depthSize = uint2(_PyramidDepthMipSize.xy);
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// Get the depth of the approximated back plane
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float pyramidDepth = LOAD_TEXTURE2D_LOD(_PyramidDepthTexture, posInputs.positionNDC * (depthSize >> 2), 2).r;
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float depth = LinearEyeDepth(pyramidDepth, _ZBufferParams);
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// Distance from point to the back plane
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float depthFromPositionInput = depth - posInputs.linearDepth;
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float offset = dot(-V, positionWS - posInputs.positionWS);
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float depthFromPosition = depthFromPositionInput - offset;
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float hitDistanceFromPosition = depthFromPosition / dot(-V, rayWS);
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return positionWS + rayWS * hitDistanceFromPosition;
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}
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//-----------------------------------------------------------------------------
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// Ligth and material classification for the deferred rendering path
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// Configure what kind of combination is supported
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//-----------------------------------------------------------------------------
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// Lighting architecture and material are suppose to be decoupled files.
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// However as we use material classification it is hard to be fully separated
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// the dependecy is define in this include where there is shared define for material and lighting in case of deferred material.
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// If a user do a lighting architecture without material classification, this can be remove
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#include "../../Lighting/LightLoop/LightLoop.cs.hlsl"
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static uint g_FeatureFlags = UINT_MAX;
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// This method allows us to know at compile time what shader features should be removed from the code when the materialID cannot be known on the whole tile (any combination of 2 or more differnet materials in the same tile)
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// This is only useful for classification during lighting, so it's not needed in EncodeIntoGBuffer and ConvertSurfaceDataToBSDFData (where we always know exactly what the MaterialID is)
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bool HasMaterialFeatureFlag(uint flag)
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{
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return ((g_FeatureFlags & flag) != 0);
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}
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// Combination need to be define in increasing "comlexity" order as define by FeatureFlagsToTileVariant
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static const uint kFeatureVariantFlags[NUM_FEATURE_VARIANTS] =
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{
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// Precomputed illumination (no dynamic lights) for all material types (except for the clear coat)
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/* 0 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_ENV | (MATERIAL_FEATURE_MASK_FLAGS & (~MATERIALFEATUREFLAGS_LIT_CLEAR_COAT)),
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// Standard>Specular
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/* 1 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | MATERIALFEATUREFLAGS_LIT_STANDARD,
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/* 2 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_AREA | MATERIALFEATUREFLAGS_LIT_STANDARD,
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/* 3 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_STANDARD,
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/* 4 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_STANDARD,
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/* 5 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIALFEATUREFLAGS_LIT_STANDARD,
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// SSS
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/* 6 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | MATERIALFEATUREFLAGS_LIT_SSS,
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/* 7 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_AREA | MATERIALFEATUREFLAGS_LIT_SSS,
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/* 8 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_SSS,
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/* 9 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_SSS,
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/* 10 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIALFEATUREFLAGS_LIT_SSS,
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// Aniso
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/* 11 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | MATERIALFEATUREFLAGS_LIT_ANISO,
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/* 12 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_AREA | MATERIALFEATUREFLAGS_LIT_ANISO,
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/* 13 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_ANISO,
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/* 14 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_ANISO,
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/* 15 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIALFEATUREFLAGS_LIT_ANISO,
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// With foliage or crowd with SSS and standard can overlap a lot, better to have a dedicated combination
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/* 16 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | MATERIALFEATUREFLAGS_LIT_SSS | MATERIALFEATUREFLAGS_LIT_STANDARD,
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/* 17 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_AREA | MATERIALFEATUREFLAGS_LIT_SSS | MATERIALFEATUREFLAGS_LIT_STANDARD,
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/* 18 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_SSS | MATERIALFEATUREFLAGS_LIT_STANDARD,
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/* 19 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_SSS | MATERIALFEATUREFLAGS_LIT_STANDARD,
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/* 20 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIALFEATUREFLAGS_LIT_SSS | MATERIALFEATUREFLAGS_LIT_STANDARD,
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// ClearCoat
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/* 21 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT,
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/* 22 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_AREA | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT,
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/* 23 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT,
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/* 24 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT,
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/* 25 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT,
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/* 26 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIAL_FEATURE_MASK_FLAGS, // Catch all case with MATERIAL_FEATURE_MASK_FLAGS is needed in case we disable material classification
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};
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uint FeatureFlagsToTileVariant(uint featureFlags)
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{
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for (int i = 0; i < NUM_FEATURE_VARIANTS; i++)
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{
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if ((featureFlags & kFeatureVariantFlags[i]) == featureFlags)
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return i;
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}
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return NUM_FEATURE_VARIANTS - 1;
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}
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// This function need to return a compile time value, else there is no optimization
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uint TileVariantToFeatureFlags(uint variant)
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{
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return kFeatureVariantFlags[variant];
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}
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//-----------------------------------------------------------------------------
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// Helper functions/variable specific to this material
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//-----------------------------------------------------------------------------
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float PackMaterialId(int materialId)
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{
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return float(materialId) / 3.0;
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}
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int UnpackMaterialId(float f)
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{
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return int(round(f * 3.0));
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}
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float3 ComputeDiffuseColor(float3 baseColor, float metallic)
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{
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return baseColor * (1.0 - metallic);
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}
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float3 ComputeFresnel0(float3 baseColor, float metallic, float dielectricF0)
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{
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return lerp(dielectricF0.xxx, baseColor, metallic);
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}
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// Fills the data which may be accessed if MATERIALFEATUREFLAGS_LIT_SSS is set.
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void FillMaterialIdSssData(int subsurfaceProfile, float radius, float thickness, uint transmissionMode,
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inout BSDFData bsdfData)
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{
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bsdfData.subsurfaceProfile = subsurfaceProfile;
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bsdfData.subsurfaceRadius = radius;
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bsdfData.enableTransmission = _EnableSSSAndTransmission != 0;
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if (bsdfData.enableTransmission && transmissionMode != SSS_TRSM_MODE_NONE)
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{
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bsdfData.thickness = _ThicknessRemaps[subsurfaceProfile].x + _ThicknessRemaps[subsurfaceProfile].y * thickness;
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bsdfData.useThickObjectMode = transmissionMode != SSS_TRSM_MODE_THIN;
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if (_UseDisneySSS != 0)
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{
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bsdfData.transmittance = ComputeTransmittanceDisney(_ShapeParams[subsurfaceProfile].rgb,
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_TransmissionTintsAndFresnel0[subsurfaceProfile].rgb,
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bsdfData.thickness, bsdfData.subsurfaceRadius);
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}
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else
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{
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bsdfData.transmittance = ComputeTransmittanceJimenez(_HalfRcpVariancesAndWeights[subsurfaceProfile][0].rgb,
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_HalfRcpVariancesAndWeights[subsurfaceProfile][0].a,
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_HalfRcpVariancesAndWeights[subsurfaceProfile][1].rgb,
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_HalfRcpVariancesAndWeights[subsurfaceProfile][1].a,
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_TransmissionTintsAndFresnel0[subsurfaceProfile].rgb,
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bsdfData.thickness, bsdfData.subsurfaceRadius);
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}
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}
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}
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void FillMaterialIdClearCoatData(float3 coatNormalWS, float coatCoverage, float coatIOR, inout BSDFData bsdfData)
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{
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bsdfData.coatNormalWS = lerp(bsdfData.normalWS, coatNormalWS, coatCoverage);
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bsdfData.coatIOR = lerp(1.0, 1.0 + coatIOR, coatCoverage);
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bsdfData.coatCoverage = coatCoverage;
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}
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void FillMaterialIdTransparencyData(float3 baseColor, float metallic, float ior, float3 transmittanceColor, float atDistance, float thickness, float transmittanceMask, inout BSDFData bsdfData)
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{
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// Uses thickness from SSS's property set
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bsdfData.ior = ior;
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// IOR define the fresnel0 value, so update it also for consistency (and even if not physical we still need to take into account any metal mask)
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bsdfData.fresnel0 = lerp(IORToFresnel0(ior).xxx, baseColor, metallic);
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bsdfData.absorptionCoefficient = TransmittanceColorAtDistanceToAbsorption (transmittanceColor, atDistance);
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bsdfData.transmittanceMask = transmittanceMask;
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bsdfData.thickness = max(thickness, 0.0001);
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}
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// For image based lighting, a part of the BSDF is pre-integrated.
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// This is done both for specular and diffuse (in case of DisneyDiffuse)
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void GetPreIntegratedFGD(float NdotV, float perceptualRoughness, float3 fresnel0, out float3 specularFGD, out float diffuseFGD, out float reflectivity)
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{
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// Pre-integrate GGX FGD
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// Integral{BSDF * <N,L> dw} =
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// Integral{(F0 + (1 - F0) * (1 - <V,H>)^5) * (BSDF / F) * <N,L> dw} =
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// F0 * Integral{(BSDF / F) * <N,L> dw} +
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// (1 - F0) * Integral{(1 - <V,H>)^5 * (BSDF / F) * <N,L> dw} =
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// (1 - F0) * x + F0 * y = lerp(x, y, F0)
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// Pre integrate DisneyDiffuse FGD:
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// z = DisneyDiffuse
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float3 preFGD = SAMPLE_TEXTURE2D_LOD(_PreIntegratedFGD, s_linear_clamp_sampler, float2(NdotV, perceptualRoughness), 0).xyz;
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specularFGD = lerp(preFGD.xxx, preFGD.yyy, fresnel0);
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#ifdef LIT_DIFFUSE_LAMBERT_BRDF
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diffuseFGD = 1.0;
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#else
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// Remap from the [0, 1] to the [0.5, 1.5] range.
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diffuseFGD = preFGD.z + 0.5;
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#endif
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reflectivity = preFGD.y;
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}
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void ApplyDebugToSurfaceData(inout SurfaceData surfaceData)
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{
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#ifdef DEBUG_DISPLAY
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if (_DebugLightingMode == DEBUGLIGHTINGMODE_SPECULAR_LIGHTING)
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{
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bool overrideSmoothness = _DebugLightingSmoothness.x != 0.0;
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float overrideSmoothnessValue = _DebugLightingSmoothness.y;
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if (overrideSmoothness)
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{
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surfaceData.perceptualSmoothness = overrideSmoothnessValue;
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}
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}
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if (_DebugLightingMode == DEBUGLIGHTINGMODE_DIFFUSE_LIGHTING)
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{
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surfaceData.baseColor = _DebugLightingAlbedo.xyz;
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}
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#endif
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}
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SSSData ConvertSurfaceDataToSSSData(SurfaceData surfaceData)
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{
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SSSData sssData;
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sssData.diffuseColor = surfaceData.baseColor;
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sssData.subsurfaceRadius = surfaceData.subsurfaceRadius;
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sssData.subsurfaceProfile = surfaceData.subsurfaceProfile;
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return sssData;
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}
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//-----------------------------------------------------------------------------
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// conversion function for forward
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//-----------------------------------------------------------------------------
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BSDFData ConvertSurfaceDataToBSDFData(SurfaceData surfaceData)
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{
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ApplyDebugToSurfaceData(surfaceData);
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BSDFData bsdfData;
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ZERO_INITIALIZE(BSDFData, bsdfData);
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bsdfData.materialId = surfaceData.materialId;
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bsdfData.specularOcclusion = surfaceData.specularOcclusion;
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bsdfData.normalWS = surfaceData.normalWS;
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bsdfData.anisotropy = surfaceData.anisotropy;
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bsdfData.perceptualRoughness = PerceptualSmoothnessToPerceptualRoughness(surfaceData.perceptualSmoothness);
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ConvertAnisotropyToRoughness(bsdfData.perceptualRoughness, bsdfData.anisotropy, bsdfData.roughnessT, bsdfData.roughnessB);
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if (surfaceData.materialId != MATERIALID_LIT_ANISO)
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{
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// Notify the material classification system that we should not use the anisotropic GGX for forward rendering.
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// Forward rendering implies automatic material classification, so normally we don't use our material classification
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// system, and set 'g_FeatureFlags' to UINT_MAX. However, since our rendering pipeline supports both forward and
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// deferred rendering, 'g_FeatureFlags' is always available, so we can use it to control GGX evaluation.
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g_FeatureFlags &= ~MATERIALFEATUREFLAGS_LIT_ANISO;
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}
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// IMPORTANT: In case of foward or gbuffer pass we must know what we are statically, so compiler can do compile time optimization
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if (bsdfData.materialId == MATERIALID_LIT_STANDARD)
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{
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bsdfData.diffuseColor = ComputeDiffuseColor(surfaceData.baseColor, surfaceData.metallic);
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bsdfData.fresnel0 = ComputeFresnel0(surfaceData.baseColor, surfaceData.metallic, DEFAULT_SPECULAR_VALUE);
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}
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else if (bsdfData.materialId == MATERIALID_LIT_SPECULAR)
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{
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// Note: Specular is not a material id but just a way to parameterize the standard materialid, thus we reset materialId to MATERIALID_LIT_STANDARD
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bsdfData.materialId = MATERIALID_LIT_STANDARD;
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bsdfData.diffuseColor = surfaceData.baseColor;
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bsdfData.fresnel0 = surfaceData.specularColor;
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}
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else if (bsdfData.materialId == MATERIALID_LIT_SSS)
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{
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bsdfData.diffuseColor = surfaceData.baseColor;
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bsdfData.fresnel0 = _TransmissionTintsAndFresnel0[surfaceData.subsurfaceProfile].a;
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uint transmissionMode = BitFieldExtract(asuint(_TransmissionFlags), 2u * surfaceData.subsurfaceProfile, 2u);
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FillMaterialIdSssData(surfaceData.subsurfaceProfile,
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surfaceData.subsurfaceRadius,
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surfaceData.thickness,
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transmissionMode, bsdfData);
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}
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else if (bsdfData.materialId == MATERIALID_LIT_ANISO)
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{
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bsdfData.diffuseColor = ComputeDiffuseColor(surfaceData.baseColor, surfaceData.metallic);
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bsdfData.fresnel0 = ComputeFresnel0(surfaceData.baseColor, surfaceData.metallic, DEFAULT_SPECULAR_VALUE);
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bsdfData.tangentWS = surfaceData.tangentWS;
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bsdfData.bitangentWS = cross(bsdfData.normalWS, bsdfData.tangentWS);
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}
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else if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT)
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{
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bsdfData.diffuseColor = ComputeDiffuseColor(surfaceData.baseColor, surfaceData.metallic);
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bsdfData.fresnel0 = ComputeFresnel0(surfaceData.baseColor, surfaceData.metallic, DEFAULT_SPECULAR_VALUE);
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// When using clear coat we assume that bottom layer is regular
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FillMaterialIdClearCoatData(surfaceData.coatNormalWS, surfaceData.coatCoverage, surfaceData.coatIOR, bsdfData);
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}
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#if HAS_REFRACTION
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// Note: Will override thickness of SSS's property set
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FillMaterialIdTransparencyData(
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surfaceData.baseColor, surfaceData.metallic, surfaceData.ior, surfaceData.transmittanceColor, surfaceData.atDistance, surfaceData.thickness, surfaceData.transmittanceMask,
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bsdfData);
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#endif
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return bsdfData;
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}
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//-----------------------------------------------------------------------------
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// conversion function for deferred
|
|
//-----------------------------------------------------------------------------
|
|
|
|
// Encode SurfaceData (BSDF parameters) into GBuffer
|
|
// Must be in sync with RT declared in HDRenderPipeline.cs ::Rebuild
|
|
void EncodeIntoGBuffer( SurfaceData surfaceData,
|
|
float3 bakeDiffuseLighting,
|
|
uint2 positionSS,
|
|
out GBufferType0 outGBuffer0,
|
|
out GBufferType1 outGBuffer1,
|
|
out GBufferType2 outGBuffer2,
|
|
out GBufferType3 outGBuffer3
|
|
)
|
|
{
|
|
ApplyDebugToSurfaceData(surfaceData);
|
|
|
|
// RT0 - 8:8:8:8 sRGB
|
|
outGBuffer0 = float4(surfaceData.baseColor, surfaceData.specularOcclusion);
|
|
|
|
// RT1 - 10:10:10:2
|
|
// We store perceptualRoughness instead of roughness because it save a sqrt ALU when decoding
|
|
// (as we want both perceptualRoughness and roughness for the lighting due to Disney Diffuse model)
|
|
// Encode normal on 20bit with oct compression + 2bit of sign
|
|
float2 octNormalWS = PackNormalOctEncode((surfaceData.materialId == MATERIALID_LIT_CLEAR_COAT) ? surfaceData.coatNormalWS : surfaceData.normalWS);
|
|
// To have more precision encode the sign of xy in a separate uint
|
|
uint octNormalSign = (octNormalWS.x < 0.0 ? 1 : 0) | (octNormalWS.y < 0.0 ? 2 : 0);
|
|
// Store octNormalSign on two bits with perceptualRoughness
|
|
outGBuffer1 = float4(abs(octNormalWS), PackFloatInt10bit(PerceptualSmoothnessToPerceptualRoughness(surfaceData.perceptualSmoothness), octNormalSign, 4.0), PackMaterialId(surfaceData.materialId));
|
|
|
|
// RT2 - 8:8:8:8
|
|
if (surfaceData.materialId == MATERIALID_LIT_STANDARD)
|
|
{
|
|
outGBuffer2 = float4(float3(0.0, 0.0, 0.0), PackFloatInt8bit(surfaceData.metallic, GBUFFER_LIT_STANDARD_REGULAR_ID, 4.0));
|
|
}
|
|
else if (surfaceData.materialId == MATERIALID_LIT_SPECULAR)
|
|
{
|
|
outGBuffer1.a = PackMaterialId(MATERIALID_LIT_STANDARD); // Encode MATERIALID_LIT_SPECULAR as MATERIALID_LIT_STANDARD + GBUFFER_LIT_STANDARD_SPECULAR_COLOR_ID value in GBuffer2
|
|
outGBuffer2 = float4(surfaceData.specularColor, PackFloatInt8bit(0.0, GBUFFER_LIT_STANDARD_SPECULAR_COLOR_ID, 4.0));
|
|
}
|
|
else if (surfaceData.materialId == MATERIALID_LIT_SSS)
|
|
{
|
|
// Special case: For SSS we will store the profile id and the subsurface radius at the location of the specular occlusion (in alpha channel of GBuffer0)
|
|
// and we will move the specular occlusion in GBuffer2. This is an optimization for SSSSS and have no other side effect as specular occlusion is always used
|
|
// during lighting pass when other buffer (Gbuffer0, 1, 2) and read anyway.
|
|
EncodeIntoSSSBuffer(ConvertSurfaceDataToSSSData(surfaceData), positionSS, outGBuffer0);
|
|
outGBuffer2 = float4(surfaceData.specularOcclusion, surfaceData.thickness, 0.0, 0.0); // Thickness is use for transmission
|
|
}
|
|
else if (surfaceData.materialId == MATERIALID_LIT_ANISO)
|
|
{
|
|
// Encode tangent on 16bit with oct compression
|
|
float2 octTangentWS = PackNormalOctEncode(surfaceData.tangentWS);
|
|
// To have more precision encode the sign of xy in a separate uint
|
|
uint octTangentSign = (octTangentWS.x < 0.0 ? 1 : 0) | (octTangentWS.y < 0.0 ? 2 : 0);
|
|
|
|
outGBuffer2 = float4(abs(octTangentWS), surfaceData.anisotropy * 0.5 + 0.5, PackFloatInt8bit(surfaceData.metallic, octTangentSign, 4.0));
|
|
}
|
|
else if (surfaceData.materialId == MATERIALID_LIT_CLEAR_COAT)
|
|
{
|
|
// In the cae of clear coat, we want more precision for the coat normal than for the bottom normal (as it is expected to be smooth). So swap the normal encoding storage in Gbuffer.
|
|
// It also allow to use clear coat normal for SSR
|
|
float2 octBottomNormalWS = PackNormalOctEncode(surfaceData.normalWS);
|
|
outGBuffer2 = float4(octBottomNormalWS * 0.5 + 0.5, surfaceData.coatCoverage, PackFloatInt8bit(surfaceData.coatIOR, (int)(surfaceData.metallic * 15.5f), 16.0) );
|
|
}
|
|
|
|
// Lighting
|
|
outGBuffer3 = float4(bakeDiffuseLighting, 0.0);
|
|
}
|
|
|
|
void DecodeFromGBuffer(
|
|
uint2 positionSS,
|
|
uint featureFlags,
|
|
out BSDFData bsdfData,
|
|
out float3 bakeDiffuseLighting)
|
|
{
|
|
GBufferType0 inGBuffer0 = LOAD_TEXTURE2D(_GBufferTexture0, positionSS);
|
|
GBufferType1 inGBuffer1 = LOAD_TEXTURE2D(_GBufferTexture1, positionSS);
|
|
GBufferType2 inGBuffer2 = LOAD_TEXTURE2D(_GBufferTexture2, positionSS);
|
|
GBufferType3 inGBuffer3 = LOAD_TEXTURE2D(_GBufferTexture3, positionSS);
|
|
|
|
ZERO_INITIALIZE(BSDFData, bsdfData);
|
|
|
|
g_FeatureFlags = featureFlags;
|
|
|
|
float3 baseColor = inGBuffer0.rgb;
|
|
bsdfData.specularOcclusion = inGBuffer0.a;
|
|
|
|
int octNormalSign;
|
|
UnpackFloatInt10bit(inGBuffer1.b, 4.0, bsdfData.perceptualRoughness, octNormalSign);
|
|
inGBuffer1.r = (octNormalSign & 1) ? -inGBuffer1.r : inGBuffer1.r;
|
|
inGBuffer1.g = (octNormalSign & 2) ? -inGBuffer1.g : inGBuffer1.g;
|
|
|
|
bsdfData.normalWS = UnpackNormalOctEncode(float2(inGBuffer1.r, inGBuffer1.g));
|
|
|
|
// The material features system for material classification must allow compile time optimization (i.e everything should be static)
|
|
// Note that as we store materialId for Aniso based on content of RT2 we need to add few extra condition.
|
|
// The code is also call from MaterialFeatureFlagsFromGBuffer, so must work fully dynamic if featureFlags is UINT_MAX
|
|
int supportsStandard = HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_STANDARD);
|
|
int supportsSSS = HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_SSS);
|
|
int supportsAniso = HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_ANISO);
|
|
int supportClearCoat = HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT);
|
|
|
|
if (supportsStandard + supportsSSS + supportsAniso + supportClearCoat > 1)
|
|
{
|
|
// only fetch materialid if it is not statically known from feature flags
|
|
bsdfData.materialId = UnpackMaterialId(inGBuffer1.a);
|
|
}
|
|
else
|
|
{
|
|
// materialid is statically known. this allows the compiler to eliminate a lot of code.
|
|
if (supportsStandard)
|
|
bsdfData.materialId = MATERIALID_LIT_STANDARD;
|
|
else if (supportsSSS)
|
|
bsdfData.materialId = MATERIALID_LIT_SSS;
|
|
else if (supportsAniso)
|
|
bsdfData.materialId = MATERIALID_LIT_ANISO;
|
|
else
|
|
bsdfData.materialId = MATERIALID_LIT_CLEAR_COAT;
|
|
}
|
|
|
|
float metallic = 0;
|
|
float dielectricF0 = DEFAULT_SPECULAR_VALUE;
|
|
bool specularColorMode = false;
|
|
|
|
// We avoid divergent evaluation of the GGX, as that nearly doubles the cost.
|
|
// If the tile has anisotropy, all the pixels within the tile are evaluated as anisotropic.
|
|
if (HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_ANISO))
|
|
{
|
|
bsdfData.anisotropy = 0;
|
|
bsdfData.tangentWS = GetLocalFrame(bsdfData.normalWS)[0];
|
|
|
|
if (bsdfData.materialId == MATERIALID_LIT_ANISO)
|
|
{
|
|
int octTangentSign;
|
|
UnpackFloatInt8bit(inGBuffer2.a, 4.0, metallic, octTangentSign);
|
|
|
|
inGBuffer2.r = (octTangentSign & 1) ? -inGBuffer2.r : inGBuffer2.r;
|
|
inGBuffer2.g = (octTangentSign & 2) ? -inGBuffer2.g : inGBuffer2.g;
|
|
|
|
bsdfData.anisotropy = inGBuffer2.b * 2 - 1;
|
|
bsdfData.tangentWS = UnpackNormalOctEncode(inGBuffer2.rg);
|
|
}
|
|
|
|
bsdfData.bitangentWS = cross(bsdfData.normalWS, bsdfData.tangentWS);
|
|
}
|
|
|
|
ConvertAnisotropyToRoughness(bsdfData.perceptualRoughness, bsdfData.anisotropy, bsdfData.roughnessT, bsdfData.roughnessB);
|
|
|
|
if (HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_SSS))
|
|
{
|
|
int subsurfaceProfile = SSS_NEUTRAL_PROFILE_ID;
|
|
uint transmissionMode = SSS_TRSM_MODE_NONE;
|
|
float radius = 0;
|
|
float thickness = 0;
|
|
|
|
if (bsdfData.materialId == MATERIALID_LIT_SSS)
|
|
{
|
|
// Reminder: when using SSS we exchange specular occlusion and subsurfaceRadius/profileID
|
|
bsdfData.specularOcclusion = inGBuffer2.r;
|
|
|
|
SSSData sssData;
|
|
DecodeFromSSSBuffer(inGBuffer0, positionSS, sssData);
|
|
|
|
subsurfaceProfile = sssData.subsurfaceProfile;
|
|
transmissionMode = BitFieldExtract(asuint(_TransmissionFlags), 2u * subsurfaceProfile, 2u);
|
|
radius = sssData.subsurfaceRadius;
|
|
thickness = inGBuffer2.g;
|
|
|
|
dielectricF0 = _TransmissionTintsAndFresnel0[subsurfaceProfile].a;
|
|
}
|
|
|
|
FillMaterialIdSssData(subsurfaceProfile, radius, thickness, transmissionMode, bsdfData);
|
|
}
|
|
|
|
if (bsdfData.materialId == MATERIALID_LIT_STANDARD && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_STANDARD))
|
|
{
|
|
int materialIdExtent;
|
|
UnpackFloatInt8bit(inGBuffer2.a, 4.0, metallic, materialIdExtent);
|
|
specularColorMode = (materialIdExtent == GBUFFER_LIT_STANDARD_SPECULAR_COLOR_ID);
|
|
}
|
|
else if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
// We have swap the encoding of the normal to have more precision for coat normal as it is more smooth
|
|
float3 coatNormalWS = bsdfData.normalWS;
|
|
bsdfData.normalWS = UnpackNormalOctEncode(float2(inGBuffer2.rg * 2.0 - 1.0));
|
|
|
|
float coatCoverage = inGBuffer2.b;
|
|
float coatIOR;
|
|
int metallic15;
|
|
UnpackFloatInt8bit(inGBuffer2.a, 16.0, coatIOR, metallic15);
|
|
metallic = metallic15 / 15.0;
|
|
|
|
// When using clear coat we assume that bottom layer is regular
|
|
FillMaterialIdClearCoatData(coatNormalWS, coatCoverage, coatIOR, bsdfData);
|
|
}
|
|
|
|
if (specularColorMode)
|
|
{
|
|
// Note: Specular is not a material id but just a way to parameterize the standard materialid, thus we reset materialId to MATERIALID_LIT_STANDARD
|
|
// For material classification it will be consider as Standard as well, thus no need to create special case
|
|
bsdfData.diffuseColor = baseColor;
|
|
bsdfData.fresnel0 = inGBuffer2.rgb;
|
|
}
|
|
else
|
|
{
|
|
bsdfData.diffuseColor = ComputeDiffuseColor(baseColor, metallic);
|
|
bsdfData.fresnel0 = ComputeFresnel0(baseColor, metallic, dielectricF0);
|
|
}
|
|
|
|
bakeDiffuseLighting = inGBuffer3.rgb;
|
|
}
|
|
|
|
// Function call from the material classification compute shader
|
|
// Note that as we store materialId on two buffer (for anisotropy case), the code need to load 2 RGBA8 buffer
|
|
uint MaterialFeatureFlagsFromGBuffer(uint2 positionSS)
|
|
{
|
|
BSDFData bsdfData;
|
|
float3 unused;
|
|
|
|
DecodeFromGBuffer(
|
|
positionSS,
|
|
UINT_MAX,
|
|
bsdfData,
|
|
unused
|
|
);
|
|
|
|
return (1 << bsdfData.materialId); // This match all the MATERIALFEATUREFLAGS_LIT_XXX flag
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Debug method (use to display values)
|
|
//-----------------------------------------------------------------------------
|
|
|
|
void GetSurfaceDataDebug(uint paramId, SurfaceData surfaceData, inout float3 result, inout bool needLinearToSRGB)
|
|
{
|
|
GetGeneratedSurfaceDataDebug(paramId, surfaceData, result, needLinearToSRGB);
|
|
}
|
|
|
|
void GetBSDFDataDebug(uint paramId, BSDFData bsdfData, inout float3 result, inout bool needLinearToSRGB)
|
|
{
|
|
GetGeneratedBSDFDataDebug(paramId, bsdfData, result, needLinearToSRGB);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// PreLightData
|
|
//-----------------------------------------------------------------------------
|
|
|
|
// Precomputed lighting data to send to the various lighting functions
|
|
struct PreLightData
|
|
{
|
|
// General
|
|
float NdotV;
|
|
|
|
// GGX
|
|
float partLambdaV;
|
|
float energyCompensation;
|
|
|
|
// Clear coat
|
|
float coatNdotV;
|
|
float ieta;
|
|
float coatFresnel0;
|
|
float3 refractV; // The view vector refracted through clear coat interface
|
|
|
|
// IBL
|
|
float3 iblDirWS; // Dominant specular direction, used for IBL in EvaluateBSDF_Env()
|
|
float iblMipLevel;
|
|
|
|
// IBL clear coat
|
|
float3 coatIblDirWS;
|
|
|
|
float3 specularFGD; // Store preconvoled BRDF for both specular and diffuse
|
|
float diffuseFGD;
|
|
|
|
// Area lights (17 VGPRs)
|
|
// TODO: 'orthoBasisViewNormal' is just a rotation around the normal and should thus be just 1x VGPR.
|
|
float3x3 orthoBasisViewNormal; // Right-handed view-dependent orthogonal basis around the normal (6x VGPRs)
|
|
float3x3 ltcTransformDiffuse; // Inverse transformation for Lambertian or Disney Diffuse (4x VGPRs)
|
|
float3x3 ltcTransformSpecular; // Inverse transformation for GGX (4x VGPRs)
|
|
float ltcMagnitudeDiffuse;
|
|
float3 ltcMagnitudeFresnel;
|
|
|
|
// area light clear coat
|
|
float3x3 ltcXformClearCoat; // TODO: make sure the compiler not wasting VGPRs on constants
|
|
float ltcClearCoatFresnelTerm;
|
|
float3x3 ltcCoatT;
|
|
|
|
// Refraction
|
|
float3 transmissionRefractV; // refracted view vector after exiting the shape
|
|
float3 transmissionPositionWS; // start of the refracted ray after exiting the shape
|
|
float3 transmissionTransmittance; // transmittance due to absorption
|
|
float transmissionSSMipLevel; // mip level of the screen space gaussian pyramid for rough refraction
|
|
};
|
|
|
|
// This is a refract - TODO: do we call original refract or this one, original maybe slightly more expensive, to check
|
|
float3 ClearCoatTransform(float3 X, float3 N, float ieta)
|
|
{
|
|
float XdotN = saturate(dot(N, X));
|
|
return ieta * X + (sqrt(1 + ieta * ieta * (XdotN * XdotN - 1)) - ieta * XdotN) * N;
|
|
}
|
|
|
|
PreLightData GetPreLightData(float3 V, PositionInputs posInput, BSDFData bsdfData)
|
|
{
|
|
PreLightData preLightData;
|
|
|
|
float3 N;
|
|
float NdotV;
|
|
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
N = bsdfData.coatNormalWS;
|
|
NdotV = saturate(dot(N, V));
|
|
preLightData.coatNdotV = NdotV;
|
|
|
|
float ieta = 1.0 / bsdfData.coatIOR; // inverse eta
|
|
preLightData.ieta = ieta;
|
|
preLightData.coatFresnel0 = Sq(bsdfData.coatIOR - 1.0) / Sq(bsdfData.coatIOR + 1.0);
|
|
|
|
// Clear coat IBL
|
|
preLightData.coatIblDirWS = reflect(-V, N);
|
|
|
|
// Clear coat area light
|
|
float theta = FastACosPos(NdotV);
|
|
float2 uv = LTC_LUT_OFFSET + LTC_LUT_SCALE * float2(0.0, theta * INV_HALF_PI); // Use Roughness of 0.0 for clearCoat roughness
|
|
|
|
// Get the inverse LTC matrix for GGX
|
|
// Note we load the matrix transpose (avoid to have to transpose it in shader)
|
|
preLightData.ltcXformClearCoat = 0.0;
|
|
preLightData.ltcXformClearCoat._m22 = 1.0;
|
|
preLightData.ltcXformClearCoat._m00_m02_m11_m20 = SAMPLE_TEXTURE2D_ARRAY_LOD(_LtcData, s_linear_clamp_sampler, uv, LTC_GGX_MATRIX_INDEX, 0);
|
|
|
|
float3 ltcMagnitude = SAMPLE_TEXTURE2D_ARRAY_LOD(_LtcData, s_linear_clamp_sampler, uv, LTC_MULTI_GGX_FRESNEL_DISNEY_DIFFUSE_INDEX, 0).rgb;
|
|
float ltcClearCoatFresnelMagnitudeDiff = ltcMagnitude.r; // The difference of magnitudes of GGX and Fresnel
|
|
float ltcClearCoatFresnelMagnitude = ltcMagnitude.g;
|
|
preLightData.ltcClearCoatFresnelTerm = preLightData.coatFresnel0 * ltcClearCoatFresnelMagnitudeDiff + ltcClearCoatFresnelMagnitude;
|
|
|
|
// TODO: Convert the area light with respect to Fresnel transmission
|
|
preLightData.ltcCoatT = float3x3( ieta + (1.0 - ieta) * N.x * N.x, 0.0 + (1.0 - ieta) * N.y * N.x, 0.0 + (1.0 - ieta) * N.z * N.x,
|
|
0.0 + (1.0 - ieta) * N.x * N.y, ieta + (1.0 - ieta) * N.y * N.y, 0.0 + (1.0 - ieta) * N.z * N.y,
|
|
0.0 + (1.0 - ieta) * N.x * N.z, 0.0 + (1.0 - ieta) * N.y * N.z, ieta + (1.0 - ieta) * N.z * N.z );
|
|
|
|
// Modify V for following calculation
|
|
preLightData.refractV = ClearCoatTransform(V, N, ieta);
|
|
V = preLightData.refractV;
|
|
}
|
|
|
|
N = bsdfData.normalWS;
|
|
NdotV = saturate(dot(N, V));
|
|
preLightData.NdotV = NdotV;
|
|
|
|
float3 iblN, iblR;
|
|
|
|
// We avoid divergent evaluation of the GGX, as that nearly doubles the cost.
|
|
// If the tile has anisotropy, all the pixels within the tile are evaluated as anisotropic.
|
|
if (HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_ANISO))
|
|
{
|
|
float TdotV = dot(bsdfData.tangentWS, V);
|
|
float BdotV = dot(bsdfData.bitangentWS, V);
|
|
|
|
preLightData.partLambdaV = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV, bsdfData.roughnessT, bsdfData.roughnessB);
|
|
|
|
// For GGX aniso and IBL we have done an empirical (eye balled) approximation compare to the reference.
|
|
// We use a single fetch, and we stretch the normal to use based on various criteria.
|
|
// result are far away from the reference but better than nothing
|
|
// For positive anisotropy values: tangent = highlight stretch (anisotropy) direction, bitangent = grain (brush) direction.
|
|
float3 grainDirWS = (bsdfData.anisotropy >= 0) ? bsdfData.bitangentWS : bsdfData.tangentWS;
|
|
// Reduce stretching for (perceptualRoughness < 0.2).
|
|
float stretch = abs(bsdfData.anisotropy) * saturate(5 * bsdfData.perceptualRoughness);
|
|
// NOTE: If we follow the theory we should use the modified normal for the different calculation implying a normal (like NdotV) and use 'anisoIblNormalWS'
|
|
// into function like GetSpecularDominantDir(). However modified normal is just a hack. The goal is just to stretch a cubemap, no accuracy here.
|
|
// With this in mind and for performance reasons we chose to only use modified normal to calculate R.
|
|
iblN = GetAnisotropicModifiedNormal(grainDirWS, N, V, stretch);
|
|
}
|
|
else
|
|
{
|
|
preLightData.partLambdaV = GetSmithJointGGXPartLambdaV(NdotV, bsdfData.roughnessT);
|
|
iblN = N;
|
|
}
|
|
|
|
iblR = reflect(-V, iblN);
|
|
|
|
float reflectivity;
|
|
|
|
// IBL
|
|
GetPreIntegratedFGD(NdotV, bsdfData.perceptualRoughness, bsdfData.fresnel0, preLightData.specularFGD, preLightData.diffuseFGD, reflectivity);
|
|
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
// Update the roughness and the IBL miplevel
|
|
// Bottom layer is affected by upper layer BRDF, result can't be more sharp than input (it is to mimic what a path tracer will do)
|
|
float roughness = PerceptualRoughnessToRoughness(bsdfData.perceptualRoughness);
|
|
float shininess = Sq(preLightData.ieta) * (2.0 / Sq(roughness) - 2.0);
|
|
roughness = sqrt(2.0 / (shininess + 2.0));
|
|
preLightData.iblDirWS = GetSpecularDominantDir(N, iblR, roughness, NdotV);
|
|
preLightData.iblMipLevel = PerceptualRoughnessToMipmapLevel(RoughnessToPerceptualRoughness(roughness));
|
|
}
|
|
else
|
|
{
|
|
// Note: this is a ad-hoc tweak.
|
|
// TODO: we need a better hack.
|
|
float iblPerceptualRoughness = bsdfData.perceptualRoughness * saturate(1.2 - abs(bsdfData.anisotropy));
|
|
float iblRoughness = PerceptualRoughnessToRoughness(iblPerceptualRoughness);
|
|
preLightData.iblDirWS = GetSpecularDominantDir(N, iblR, iblRoughness, NdotV);
|
|
preLightData.iblMipLevel = PerceptualRoughnessToMipmapLevel(iblPerceptualRoughness);
|
|
}
|
|
|
|
#ifdef LIT_USE_GGX_ENERGY_COMPENSATION
|
|
// Ref: Practical multiple scattering compensation for microfacet models.
|
|
// We only apply the formulation for metals.
|
|
// For dielectrics, the change of reflectance is negligible.
|
|
// We deem the intensity difference of a couple of percent for high values of roughness
|
|
// to not be worth the cost of another precomputed table.
|
|
// Note: this formulation bakes the BSDF non-symmetric!
|
|
preLightData.energyCompensation = 1.0 / reflectivity - 1.0;
|
|
#else
|
|
preLightData.energyCompensation = 0.0;
|
|
#endif // LIT_USE_GGX_ENERGY_COMPENSATION
|
|
|
|
// Area light
|
|
// UVs for sampling the LUTs
|
|
float theta = FastACosPos(NdotV); // For Area light - UVs for sampling the LUTs
|
|
float2 uv = LTC_LUT_OFFSET + LTC_LUT_SCALE * float2(bsdfData.perceptualRoughness, theta * INV_HALF_PI);
|
|
|
|
// Note we load the matrix transpose (avoid to have to transpose it in shader)
|
|
#ifdef LIT_DIFFUSE_LAMBERT_BRDF
|
|
preLightData.ltcTransformDiffuse = k_identity3x3;
|
|
#else
|
|
// Get the inverse LTC matrix for Disney Diffuse
|
|
preLightData.ltcTransformDiffuse = 0.0;
|
|
preLightData.ltcTransformDiffuse._m22 = 1.0;
|
|
preLightData.ltcTransformDiffuse._m00_m02_m11_m20 = SAMPLE_TEXTURE2D_ARRAY_LOD(_LtcData, s_linear_clamp_sampler, uv, LTC_DISNEY_DIFFUSE_MATRIX_INDEX, 0);
|
|
#endif
|
|
|
|
// Get the inverse LTC matrix for GGX
|
|
// Note we load the matrix transpose (avoid to have to transpose it in shader)
|
|
preLightData.ltcTransformSpecular = 0.0;
|
|
preLightData.ltcTransformSpecular._m22 = 1.0;
|
|
preLightData.ltcTransformSpecular._m00_m02_m11_m20 = SAMPLE_TEXTURE2D_ARRAY_LOD(_LtcData, s_linear_clamp_sampler, uv, LTC_GGX_MATRIX_INDEX, 0);
|
|
|
|
// Construct a right-handed view-dependent orthogonal basis around the normal
|
|
preLightData.orthoBasisViewNormal[0] = normalize(V - N * NdotV);
|
|
preLightData.orthoBasisViewNormal[2] = N;
|
|
preLightData.orthoBasisViewNormal[1] = cross(preLightData.orthoBasisViewNormal[2], preLightData.orthoBasisViewNormal[0]);
|
|
|
|
float3 ltcMagnitude = SAMPLE_TEXTURE2D_ARRAY_LOD(_LtcData, s_linear_clamp_sampler, uv, LTC_MULTI_GGX_FRESNEL_DISNEY_DIFFUSE_INDEX, 0).rgb;
|
|
float ltcGGXFresnelMagnitudeDiff = ltcMagnitude.r; // The difference of magnitudes of GGX and Fresnel
|
|
float ltcGGXFresnelMagnitude = ltcMagnitude.g;
|
|
float ltcDisneyDiffuseMagnitude = ltcMagnitude.b;
|
|
|
|
#ifdef LIT_DIFFUSE_LAMBERT_BRDF
|
|
preLightData.ltcMagnitudeDiffuse = 1;
|
|
#else
|
|
preLightData.ltcMagnitudeDiffuse = ltcDisneyDiffuseMagnitude;
|
|
#endif
|
|
|
|
// TODO: the fit seems rather poor. The scaling factor of 0.5 allows us
|
|
// to match the reference for rough metals, but further darkens dielectrics.
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
// Change the Fresnel term to account for transmission through Clear Coat and reflection on the base layer
|
|
float F = F_Schlick(preLightData.coatFresnel0, preLightData.coatNdotV);
|
|
F = Sq(-F * bsdfData.coatCoverage + 1.0);
|
|
F /= preLightData.ieta; //TODO: LaurentB why / ieta here and not for other lights ?
|
|
|
|
preLightData.ltcMagnitudeFresnel = F * bsdfData.fresnel0 * ltcGGXFresnelMagnitudeDiff + (float3)ltcGGXFresnelMagnitude;
|
|
}
|
|
else
|
|
{
|
|
preLightData.ltcMagnitudeFresnel = bsdfData.fresnel0 * ltcGGXFresnelMagnitudeDiff + (float3)ltcGGXFresnelMagnitude;
|
|
}
|
|
|
|
#ifdef REFRACTION_MODEL
|
|
RefractionModelResult refraction = REFRACTION_MODEL(V, posInput, bsdfData);
|
|
preLightData.transmissionRefractV = refraction.rayWS;
|
|
preLightData.transmissionPositionWS = refraction.positionWS;
|
|
preLightData.transmissionTransmittance = exp(-bsdfData.absorptionCoefficient * refraction.distance);
|
|
// Empirical remap to try to match a bit the refractio probe blurring for the fallback
|
|
preLightData.transmissionSSMipLevel = sqrt(bsdfData.perceptualRoughness) * uint(_GaussianPyramidColorMipSize.z);
|
|
#else
|
|
preLightData.transmissionRefractV = -V;
|
|
preLightData.transmissionPositionWS = posInput.positionWS;
|
|
preLightData.transmissionTransmittance = float3(1.0, 1.0, 1.0);
|
|
preLightData.transmissionSSMipLevel = 0;
|
|
#endif
|
|
|
|
return preLightData;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// bake lighting function
|
|
//-----------------------------------------------------------------------------
|
|
|
|
// GetBakedDiffuseLigthing function compute the bake lighting + emissive color to be store in emissive buffer (Deferred case)
|
|
// In forward it must be add to the final contribution.
|
|
// This function require the 3 structure surfaceData, builtinData, bsdfData because it may require both the engine side data, and data that will not be store inside the gbuffer.
|
|
float3 GetBakedDiffuseLigthing(SurfaceData surfaceData, BuiltinData builtinData, BSDFData bsdfData, PreLightData preLightData)
|
|
{
|
|
if (bsdfData.materialId == MATERIALID_LIT_SSS)
|
|
{
|
|
bsdfData.diffuseColor = ApplyDiffuseTexturingMode(bsdfData.diffuseColor, bsdfData.subsurfaceProfile);
|
|
}
|
|
|
|
// Premultiply bake diffuse lighting information with DisneyDiffuse pre-integration
|
|
return builtinData.bakeDiffuseLighting * preLightData.diffuseFGD * surfaceData.ambientOcclusion * bsdfData.diffuseColor + builtinData.emissiveColor;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// light transport functions
|
|
//-----------------------------------------------------------------------------
|
|
|
|
LightTransportData GetLightTransportData(SurfaceData surfaceData, BuiltinData builtinData, BSDFData bsdfData)
|
|
{
|
|
LightTransportData lightTransportData;
|
|
|
|
// diffuseColor for lightmapping should basically be diffuse color.
|
|
// But rough metals (black diffuse) still scatter quite a lot of light around, so
|
|
// we want to take some of that into account too.
|
|
|
|
float roughness = PerceptualRoughnessToRoughness(bsdfData.perceptualRoughness);
|
|
lightTransportData.diffuseColor = bsdfData.diffuseColor + bsdfData.fresnel0 * roughness * 0.5 * surfaceData.metallic;
|
|
lightTransportData.emissiveColor = builtinData.emissiveColor;
|
|
|
|
return lightTransportData;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// LightLoop related function (Only include if required)
|
|
// HAS_LIGHTLOOP is define in Lighting.hlsl
|
|
//-----------------------------------------------------------------------------
|
|
|
|
#ifdef HAS_LIGHTLOOP
|
|
|
|
#ifndef _SURFACE_TYPE_TRANSPARENT
|
|
#define USE_DEFERRED_DIRECTIONAL_SHADOWS // Deferred shadows are always enabled for opaque objects
|
|
#endif
|
|
|
|
#include "../../Lighting/LightEvaluation.hlsl"
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Lighting structure for light accumulation
|
|
//-----------------------------------------------------------------------------
|
|
|
|
// These structure allow to accumulate lighting accross the Lit material
|
|
// AggregateLighting is init to zero and transfer to EvaluateBSDF, but the LightLoop can't access its content.
|
|
struct DirectLighting
|
|
{
|
|
float3 diffuse;
|
|
float3 specular;
|
|
};
|
|
|
|
struct IndirectLighting
|
|
{
|
|
float3 specularReflected;
|
|
float3 specularTransmitted;
|
|
};
|
|
|
|
struct AggregateLighting
|
|
{
|
|
DirectLighting direct;
|
|
IndirectLighting indirect;
|
|
};
|
|
|
|
void AccumulateDirectLighting(DirectLighting src, inout AggregateLighting dst)
|
|
{
|
|
dst.direct.diffuse += src.diffuse;
|
|
dst.direct.specular += src.specular;
|
|
}
|
|
|
|
void AccumulateIndirectLighting(IndirectLighting src, inout AggregateLighting dst)
|
|
{
|
|
dst.indirect.specularReflected += src.specularReflected;
|
|
dst.indirect.specularTransmitted += src.specularTransmitted;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// BSDF share between directional light, punctual light and area light (reference)
|
|
//-----------------------------------------------------------------------------
|
|
|
|
void BSDF( float3 V, float3 L, float3 positionWS, PreLightData preLightData, BSDFData bsdfData,
|
|
out float3 diffuseLighting,
|
|
out float3 specularLighting)
|
|
{
|
|
float3 F = 1.0;
|
|
specularLighting = float3(0.0, 0.0, 0.0);
|
|
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT) )
|
|
{
|
|
// Optimized math. Ref: PBR Diffuse Lighting for GGX + Smith Microsurfaces (slide 114).
|
|
float NdotL = saturate(dot(bsdfData.coatNormalWS, L));
|
|
float NdotV = preLightData.coatNdotV;
|
|
float LdotV = dot(L, V);
|
|
float invLenLV = rsqrt(max(2 * LdotV + 2, FLT_EPS));
|
|
float NdotH = saturate((NdotL + NdotV) * invLenLV);
|
|
float LdotH = saturate(invLenLV * LdotV + invLenLV);
|
|
|
|
// Evaluate Fresnel on the Clear Coat
|
|
F = F_Schlick(preLightData.coatFresnel0, LdotH);
|
|
// TODO: No need to call D (to see with LaurentB) + question on * NdotL
|
|
specularLighting += F * D_GGX(NdotH, 0.01) * NdotL * bsdfData.coatCoverage;
|
|
|
|
// Change the Fresnel term to account for transmission through Clear Coat and reflection on the base layer
|
|
F = Sq(-F * bsdfData.coatCoverage + 1.0);
|
|
|
|
// Change the Light and View direction to account for IOR change.
|
|
// Update the half vector accordingly
|
|
V = preLightData.refractV;
|
|
L = ClearCoatTransform(L, bsdfData.coatNormalWS, preLightData.ieta);
|
|
}
|
|
|
|
// Optimized math. Ref: PBR Diffuse Lighting for GGX + Smith Microsurfaces (slide 114).
|
|
float NdotL = saturate(dot(bsdfData.normalWS, L)); // Must have the same value without the clamp
|
|
float NdotV = preLightData.NdotV; // Get the unaltered (geometric) version
|
|
float LdotV = dot(L, V);
|
|
float invLenLV = rsqrt(max(2 * LdotV + 2, FLT_EPS)); // invLenLV = rcp(length(L + V)) - caution about the case where V and L are opposite, it can happen, use max to avoid this
|
|
float NdotH = saturate((NdotL + NdotV) * invLenLV);
|
|
float LdotH = saturate(invLenLV * LdotV + invLenLV);
|
|
|
|
F *= F_Schlick(bsdfData.fresnel0, LdotH);
|
|
|
|
float DV;
|
|
|
|
// We avoid divergent evaluation of the GGX, as that nearly doubles the cost.
|
|
// If the tile has anisotropy, all the pixels within the tile are evaluated as anisotropic.
|
|
if (HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_ANISO))
|
|
{
|
|
float3 H = (L + V) * invLenLV;
|
|
// For anisotropy we must not saturate these values
|
|
float TdotH = dot(bsdfData.tangentWS, H);
|
|
float TdotL = dot(bsdfData.tangentWS, L);
|
|
float BdotH = dot(bsdfData.bitangentWS, H);
|
|
float BdotL = dot(bsdfData.bitangentWS, L);
|
|
|
|
|
|
// TODO: Do comparison between this correct version and the one from isotropic and see if there is any visual difference
|
|
DV = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH, NdotV, TdotL, BdotL, NdotL,
|
|
bsdfData.roughnessT, bsdfData.roughnessB, preLightData.partLambdaV);
|
|
}
|
|
else
|
|
{
|
|
|
|
DV = DV_SmithJointGGX(NdotH, NdotL, NdotV, bsdfData.roughnessT, preLightData.partLambdaV);
|
|
}
|
|
specularLighting += F * DV;
|
|
|
|
#ifdef LIT_DIFFUSE_LAMBERT_BRDF
|
|
float diffuseTerm = Lambert();
|
|
#elif LIT_DIFFUSE_GGX_BRDF
|
|
float roughness = PerceptualRoughnessToRoughness(bsdfData.perceptualRoughness);
|
|
float3 diffuseTerm = DiffuseGGX(bsdfData.diffuseColor, NdotV, NdotL, NdotH, LdotV, roughness);
|
|
#else
|
|
// A note on subsurface scattering: [SSS-NOTE-TRSM]
|
|
// The correct way to handle SSS is to transmit light inside the surface, perform SSS,
|
|
// and then transmit it outside towards the viewer.
|
|
// Transmit(X) = F_Transm_Schlick(F0, F90, NdotX), where F0 = 0, F90 = 1.
|
|
// Therefore, the diffuse BSDF should be decomposed as follows:
|
|
// f_d = A / Pi * F_Transm_Schlick(0, 1, NdotL) * F_Transm_Schlick(0, 1, NdotV) + f_d_reflection,
|
|
// with F_Transm_Schlick(0, 1, NdotV) applied after the SSS pass.
|
|
// The alternative (artistic) formulation of Disney is to set F90 = 0.5:
|
|
// f_d = A / Pi * F_Transm_Schlick(0, 0.5, NdotL) * F_Transm_Schlick(0, 0.5, NdotV) + f_retro_reflection.
|
|
// That way, darkening at grading angles is reduced to 0.5.
|
|
// In practice, applying F_Transm_Schlick(F0, F90, NdotV) after the SSS pass is expensive,
|
|
// as it forces us to read the normal buffer at the end of the SSS pass.
|
|
// Separating f_retro_reflection also has a small cost (mostly due to energy compensation
|
|
// for multi-bounce GGX), and the visual difference is negligible.
|
|
// Therefore, we choose not to separate diffuse lighting into reflected and transmitted.
|
|
float diffuseTerm = DisneyDiffuse(NdotV, NdotL, LdotV, bsdfData.perceptualRoughness);
|
|
#endif
|
|
|
|
// We don't multiply by 'bsdfData.diffuseColor' here. It's done only once in PostEvaluateBSDF().
|
|
diffuseLighting = diffuseTerm;
|
|
}
|
|
|
|
// In the "thin object" mode (for cards), we assume that the geometry is very thin.
|
|
// We apply wrapped lighting to compensate for that, and do not modify the shading position.
|
|
// Otherwise, in the "thick object" mode, we can have EITHER reflected (front) lighting
|
|
// OR transmitted (back) lighting, never both at the same time. For transmitted lighting,
|
|
// we need to push the shading position back to avoid self-shadowing problems.
|
|
float3 ComputeThicknessDisplacement(BSDFData bsdfData, float3 L, float NdotL)
|
|
{
|
|
float displacement = 0;
|
|
|
|
[flatten] if (bsdfData.useThickObjectMode && NdotL < 0)
|
|
{
|
|
// Compute the thickness in world units along the normal.
|
|
float thicknessInMeters = bsdfData.thickness * METERS_PER_MILLIMETER;
|
|
float thicknessInUnits = thicknessInMeters * _WorldScales[bsdfData.subsurfaceProfile].y;
|
|
|
|
// Compute the thickness in world units along the light vector.
|
|
displacement = thicknessInUnits / -NdotL;
|
|
}
|
|
|
|
return displacement * L;
|
|
}
|
|
|
|
// Currently, we only model diffuse transmission. Specular transmission is not yet supported.
|
|
// Transmitted lighting is computed as follows:
|
|
// - we assume that the object is a thick plane (slab);
|
|
// - we reverse the front-facing normal for the back of the object;
|
|
// - we assume that the incoming radiance is constant along the entire back surface;
|
|
// - we apply BSDF-specific diffuse transmission to transmit the light subsurface and back;
|
|
// - we integrate the diffuse reflectance profile w.r.t. the radius (while also accounting
|
|
// for the thickness) to compute the transmittance;
|
|
// - we multiply the transmitted radiance by the transmittance.
|
|
float3 EvaluateTransmission(BSDFData bsdfData, float NdotL, float NdotV, float attenuation)
|
|
{
|
|
float wrappedNdotL = ComputeWrappedDiffuseLighting(-NdotL, SSS_WRAP_LIGHT);
|
|
float negatedNdotL = saturate(-NdotL);
|
|
|
|
// Apply wrapped lighting to better handle thin objects (cards) at grazing angles.
|
|
float backNdotL = bsdfData.useThickObjectMode ? negatedNdotL : wrappedNdotL;
|
|
|
|
// Apply BSDF-specific diffuse transmission to attenuation. See also: [SSS-NOTE-TRSM]
|
|
// We don't multiply by 'bsdfData.diffuseColor' here. It's done only once in PostEvaluateBSDF().
|
|
#ifdef LIT_DIFFUSE_LAMBERT_BRDF
|
|
attenuation *= Lambert();
|
|
#else
|
|
attenuation *= INV_PI * F_Transm_Schlick(0, 0.5, NdotV) * F_Transm_Schlick(0, 0.5, backNdotL);
|
|
#endif
|
|
|
|
float intensity = attenuation * backNdotL;
|
|
|
|
return intensity * bsdfData.transmittance;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// EvaluateBSDF_Directional
|
|
//-----------------------------------------------------------------------------
|
|
|
|
DirectLighting EvaluateBSDF_Directional(LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput, PreLightData preLightData,
|
|
DirectionalLightData lightData, BSDFData bsdfData,
|
|
BakeLightingData bakeLightingData)
|
|
{
|
|
DirectLighting lighting;
|
|
ZERO_INITIALIZE(DirectLighting, lighting);
|
|
|
|
float3 N = bsdfData.normalWS;
|
|
float3 L = -lightData.forward; // Lights point backward in Unity
|
|
float NdotL = dot(N, L);
|
|
|
|
posInput.positionWS += ComputeThicknessDisplacement(bsdfData, L, NdotL);
|
|
|
|
float3 color; float attenuation;
|
|
EvaluateLight_Directional(lightLoopContext, posInput, lightData, bakeLightingData, N, L,
|
|
color, attenuation);
|
|
|
|
float intensity = attenuation * saturate(NdotL);
|
|
|
|
[branch] if (intensity > 0)
|
|
{
|
|
BSDF(V, L, posInput.positionWS, preLightData, bsdfData, lighting.diffuse, lighting.specular);
|
|
|
|
lighting.diffuse *= intensity * lightData.diffuseScale;
|
|
lighting.specular *= intensity * lightData.specularScale;
|
|
}
|
|
|
|
[branch] if (bsdfData.enableTransmission)
|
|
{
|
|
// We use diffuse lighting for accumulation since it is going to be blurred during the SSS pass.
|
|
lighting.diffuse += EvaluateTransmission(bsdfData, NdotL, preLightData.NdotV, attenuation * lightData.diffuseScale);
|
|
}
|
|
|
|
// Save ALU by applying light and cookie colors only once.
|
|
lighting.diffuse *= color;
|
|
lighting.specular *= color;
|
|
|
|
return lighting;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// EvaluateBSDF_Punctual (supports spot, point and projector lights)
|
|
//-----------------------------------------------------------------------------
|
|
|
|
DirectLighting EvaluateBSDF_Punctual(LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput,
|
|
PreLightData preLightData, LightData lightData, BSDFData bsdfData, BakeLightingData bakeLightingData)
|
|
{
|
|
DirectLighting lighting;
|
|
ZERO_INITIALIZE(DirectLighting, lighting);
|
|
|
|
float3 lightToSample = posInput.positionWS - lightData.positionWS;
|
|
int lightType = lightData.lightType;
|
|
|
|
float3 unL = (lightType != GPULIGHTTYPE_PROJECTOR_BOX) ? -lightToSample : -lightData.forward;
|
|
float distSq = dot(unL, unL);
|
|
float distRcp = rsqrt(distSq);
|
|
float dist = distSq * distRcp;
|
|
float3 N = bsdfData.normalWS;
|
|
float3 L = unL * distRcp;
|
|
float NdotL = dot(N, L);
|
|
|
|
posInput.positionWS += ComputeThicknessDisplacement(bsdfData, L, NdotL);
|
|
|
|
float3 color; float attenuation;
|
|
EvaluateLight_Punctual(lightLoopContext, posInput, lightData, bakeLightingData, N, L, dist, distSq,
|
|
color, attenuation);
|
|
|
|
float intensity = attenuation * saturate(NdotL);
|
|
|
|
[branch] if (intensity > 0)
|
|
{
|
|
// Simulate a sphere light with this hack.
|
|
bsdfData.roughnessT = max(bsdfData.roughnessT, lightData.minRoughness);
|
|
bsdfData.roughnessB = max(bsdfData.roughnessB, lightData.minRoughness);
|
|
|
|
BSDF(V, L, posInput.positionWS, preLightData, bsdfData, lighting.diffuse, lighting.specular);
|
|
|
|
lighting.diffuse *= intensity * lightData.diffuseScale;
|
|
lighting.specular *= intensity * lightData.specularScale;
|
|
}
|
|
|
|
[branch] if (bsdfData.enableTransmission)
|
|
{
|
|
// We use diffuse lighting for accumulation since it is going to be blurred during the SSS pass.
|
|
lighting.diffuse += EvaluateTransmission(bsdfData, NdotL, preLightData.NdotV, attenuation * lightData.diffuseScale);
|
|
}
|
|
|
|
// Save ALU by applying light and cookie colors only once.
|
|
lighting.diffuse *= color;
|
|
lighting.specular *= color;
|
|
|
|
return lighting;
|
|
}
|
|
|
|
#include "LitReference.hlsl"
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// EvaluateBSDF_Line - Approximation with Linearly Transformed Cosines
|
|
//-----------------------------------------------------------------------------
|
|
|
|
DirectLighting EvaluateBSDF_Line( LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput,
|
|
PreLightData preLightData, LightData lightData, BSDFData bsdfData, BakeLightingData bakeLightingData)
|
|
{
|
|
DirectLighting lighting;
|
|
ZERO_INITIALIZE(DirectLighting, lighting);
|
|
|
|
float3 positionWS = posInput.positionWS;
|
|
|
|
#ifdef LIT_DISPLAY_REFERENCE_AREA
|
|
IntegrateBSDF_LineRef(V, positionWS, preLightData, lightData, bsdfData,
|
|
lighting.diffuse, lighting.specular);
|
|
#else
|
|
float len = lightData.size.x;
|
|
float3 T = lightData.right;
|
|
|
|
float3 unL = lightData.positionWS - positionWS;
|
|
|
|
// Pick the major axis of the ellipsoid.
|
|
float3 axis = lightData.right;
|
|
|
|
// We define the ellipsoid s.t. r1 = (r + len / 2), r2 = r3 = r.
|
|
// TODO: This could be precomputed.
|
|
float radius = rsqrt(lightData.invSqrAttenuationRadius);
|
|
float invAspectRatio = radius / (radius + (0.5 * len));
|
|
|
|
// Compute the light attenuation.
|
|
float intensity = GetEllipsoidalDistanceAttenuation(unL, lightData.invSqrAttenuationRadius,
|
|
axis, invAspectRatio);
|
|
|
|
// Terminate if the shaded point is too far away.
|
|
if (intensity == 0.0)
|
|
return lighting;
|
|
|
|
lightData.diffuseScale *= intensity;
|
|
lightData.specularScale *= intensity;
|
|
|
|
// Translate the light s.t. the shaded point is at the origin of the coordinate system.
|
|
lightData.positionWS -= positionWS;
|
|
|
|
// TODO: some of this could be precomputed.
|
|
float3 P1 = lightData.positionWS - T * (0.5 * len);
|
|
float3 P2 = lightData.positionWS + T * (0.5 * len);
|
|
|
|
// Rotate the endpoints into the local coordinate system.
|
|
P1 = mul(P1, transpose(preLightData.orthoBasisViewNormal));
|
|
P2 = mul(P2, transpose(preLightData.orthoBasisViewNormal));
|
|
|
|
// Compute the binormal in the local coordinate system.
|
|
float3 B = normalize(cross(P1, P2));
|
|
|
|
float ltcValue;
|
|
|
|
// Evaluate the diffuse part
|
|
{
|
|
ltcValue = LTCEvaluate(P1, P2, B, preLightData.ltcTransformDiffuse);
|
|
ltcValue *= lightData.diffuseScale;
|
|
// We don't multiply by 'bsdfData.diffuseColor' here. It's done only once in PostEvaluateBSDF().
|
|
lighting.diffuse = preLightData.ltcMagnitudeDiffuse * ltcValue;
|
|
}
|
|
|
|
[branch] if (bsdfData.enableTransmission)
|
|
{
|
|
// Flip the view vector and the normal. The bitangent stays the same.
|
|
float3x3 flipMatrix = float3x3(-1, 0, 0,
|
|
0, 1, 0,
|
|
0, 0, -1);
|
|
|
|
// Use the Lambertian approximation for performance reasons.
|
|
// The matrix multiplication should not generate any extra ALU on GCN.
|
|
// TODO: double evaluation is very inefficient! This is a temporary solution.
|
|
ltcValue = LTCEvaluate(P1, P2, B, mul(flipMatrix, k_identity3x3));
|
|
ltcValue *= lightData.diffuseScale;
|
|
|
|
// We use diffuse lighting for accumulation since it is going to be blurred during the SSS pass.
|
|
// We don't multiply by 'bsdfData.diffuseColor' here. It's done only once in PostEvaluateBSDF().
|
|
lighting.diffuse += bsdfData.transmittance * ltcValue;
|
|
}
|
|
|
|
// Evaluate the coat part
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
// TODO
|
|
// ltcValue = LTCEvaluate(P1, P2, B, preLightData.ltcXformClearCoat);
|
|
// ltcValue *= lightData.specularScale;
|
|
// specularLighting = preLightData.ltcClearCoatFresnelTerm * (ltcValue * bsdfData.coatCoverage);
|
|
}
|
|
|
|
// Evaluate the specular part
|
|
{
|
|
ltcValue = LTCEvaluate(P1, P2, B, preLightData.ltcTransformSpecular);
|
|
ltcValue *= lightData.specularScale;
|
|
lighting.specular += preLightData.ltcMagnitudeFresnel * ltcValue;
|
|
}
|
|
|
|
// Save ALU by applying 'lightData.color' only once.
|
|
lighting.diffuse *= lightData.color;
|
|
lighting.specular *= lightData.color;
|
|
#endif // LIT_DISPLAY_REFERENCE_AREA
|
|
|
|
return lighting;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// EvaluateBSDF_Area - Approximation with Linearly Transformed Cosines
|
|
//-----------------------------------------------------------------------------
|
|
|
|
// #define ELLIPSOIDAL_ATTENUATION
|
|
|
|
DirectLighting EvaluateBSDF_Rect( LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput,
|
|
PreLightData preLightData, LightData lightData, BSDFData bsdfData, BakeLightingData bakeLightingData)
|
|
{
|
|
DirectLighting lighting;
|
|
ZERO_INITIALIZE(DirectLighting, lighting);
|
|
|
|
float3 positionWS = posInput.positionWS;
|
|
|
|
#ifdef LIT_DISPLAY_REFERENCE_AREA
|
|
IntegrateBSDF_AreaRef(V, positionWS, preLightData, lightData, bsdfData,
|
|
lighting.diffuse, lighting.specular);
|
|
#else
|
|
float3 unL = lightData.positionWS - positionWS;
|
|
|
|
if (dot(lightData.forward, unL) >= 0.0001)
|
|
{
|
|
// The light is back-facing.
|
|
return lighting;
|
|
}
|
|
|
|
// Rotate the light direction into the light space.
|
|
float3x3 lightToWorld = float3x3(lightData.right, lightData.up, -lightData.forward);
|
|
unL = mul(unL, transpose(lightToWorld));
|
|
|
|
// TODO: This could be precomputed.
|
|
float halfWidth = lightData.size.x * 0.5;
|
|
float halfHeight = lightData.size.y * 0.5;
|
|
|
|
// Define the dimensions of the attenuation volume.
|
|
// TODO: This could be precomputed.
|
|
float radius = rsqrt(lightData.invSqrAttenuationRadius);
|
|
float3 invHalfDim = rcp(float3(radius + halfWidth,
|
|
radius + halfHeight,
|
|
radius));
|
|
|
|
// Compute the light attenuation.
|
|
#ifdef ELLIPSOIDAL_ATTENUATION
|
|
// The attenuation volume is an axis-aligned ellipsoid s.t.
|
|
// r1 = (r + w / 2), r2 = (r + h / 2), r3 = r.
|
|
float intensity = GetEllipsoidalDistanceAttenuation(unL, invHalfDim);
|
|
#else
|
|
// The attenuation volume is an axis-aligned box s.t.
|
|
// hX = (r + w / 2), hY = (r + h / 2), hZ = r.
|
|
float intensity = GetBoxDistanceAttenuation(unL, invHalfDim);
|
|
#endif
|
|
|
|
// Terminate if the shaded point is too far away.
|
|
if (intensity == 0.0)
|
|
return lighting;
|
|
|
|
lightData.diffuseScale *= intensity;
|
|
lightData.specularScale *= intensity;
|
|
|
|
// Translate the light s.t. the shaded point is at the origin of the coordinate system.
|
|
lightData.positionWS -= positionWS;
|
|
|
|
float4x3 lightVerts;
|
|
|
|
// TODO: some of this could be precomputed.
|
|
lightVerts[0] = lightData.positionWS + lightData.right * halfWidth + lightData.up * halfHeight;
|
|
lightVerts[1] = lightData.positionWS + lightData.right * halfWidth + lightData.up * -halfHeight;
|
|
lightVerts[2] = lightData.positionWS + lightData.right * -halfWidth + lightData.up * -halfHeight;
|
|
lightVerts[3] = lightData.positionWS + lightData.right * -halfWidth + lightData.up * halfHeight;
|
|
|
|
// Rotate the endpoints into the local coordinate system.
|
|
lightVerts = mul(lightVerts, transpose(preLightData.orthoBasisViewNormal));
|
|
|
|
float ltcValue;
|
|
|
|
// Evaluate the diffuse part
|
|
{
|
|
// Polygon irradiance in the transformed configuration.
|
|
ltcValue = PolygonIrradiance(mul(lightVerts, preLightData.ltcTransformDiffuse));
|
|
ltcValue *= lightData.diffuseScale;
|
|
// We don't multiply by 'bsdfData.diffuseColor' here. It's done only once in PostEvaluateBSDF().
|
|
lighting.diffuse = preLightData.ltcMagnitudeDiffuse * ltcValue;
|
|
}
|
|
|
|
[branch] if (bsdfData.enableTransmission)
|
|
{
|
|
// Flip the view vector and the normal. The bitangent stays the same.
|
|
float3x3 flipMatrix = float3x3(-1, 0, 0,
|
|
0, 1, 0,
|
|
0, 0, -1);
|
|
|
|
// Use the Lambertian approximation for performance reasons.
|
|
// The matrix multiplication should not generate any extra ALU on GCN.
|
|
float3x3 ltcTransform = mul(flipMatrix, k_identity3x3);
|
|
|
|
// Polygon irradiance in the transformed configuration.
|
|
// TODO: double evaluation is very inefficient! This is a temporary solution.
|
|
ltcValue = PolygonIrradiance(mul(lightVerts, ltcTransform));
|
|
ltcValue *= lightData.diffuseScale;
|
|
|
|
// We use diffuse lighting for accumulation since it is going to be blurred during the SSS pass.
|
|
// We don't multiply by 'bsdfData.diffuseColor' here. It's done only once in PostEvaluateBSDF().
|
|
lighting.diffuse += bsdfData.transmittance * ltcValue;
|
|
}
|
|
|
|
// Evaluate the coat part
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
// TODO
|
|
// ltcValue = LTCEvaluate(lightVerts, V, bsdfData.coatNormalWS, preLightData.coatNdotV, preLightData.ltcXformClearCoat);
|
|
// lighting.specular = preLightData.ltcClearCoatFresnelTerm * (ltcValue * bsdfData.coatCoverage);
|
|
|
|
// modify matL value based on Fresnel transmission
|
|
// matL = mul(matL, preLightData.ltcCoatT);
|
|
|
|
// V = preLightData.refractV;
|
|
}
|
|
|
|
// Evaluate the specular part
|
|
{
|
|
// Polygon irradiance in the transformed configuration.
|
|
ltcValue = PolygonIrradiance(mul(lightVerts, preLightData.ltcTransformSpecular));
|
|
ltcValue *= lightData.specularScale;
|
|
lighting.specular += preLightData.ltcMagnitudeFresnel * ltcValue;
|
|
}
|
|
|
|
// Save ALU by applying 'lightData.color' only once.
|
|
lighting.diffuse *= lightData.color;
|
|
lighting.specular *= lightData.color;
|
|
#endif // LIT_DISPLAY_REFERENCE_AREA
|
|
|
|
return lighting;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// EvaluateBSDF_SSLighting for screen space lighting
|
|
// ----------------------------------------------------------------------------
|
|
|
|
IndirectLighting EvaluateBSDF_SSReflection(LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput,
|
|
PreLightData preLightData, BSDFData bsdfData,
|
|
inout float hierarchyWeight)
|
|
{
|
|
IndirectLighting lighting;
|
|
ZERO_INITIALIZE(IndirectLighting, lighting);
|
|
|
|
// TODO
|
|
|
|
return lighting;
|
|
}
|
|
|
|
IndirectLighting EvaluateBSDF_SSRefraction(LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput,
|
|
PreLightData preLightData, BSDFData bsdfData,
|
|
inout float hierarchyWeight)
|
|
{
|
|
IndirectLighting lighting;
|
|
ZERO_INITIALIZE(IndirectLighting, lighting);
|
|
|
|
#if HAS_REFRACTION
|
|
// Refraction process:
|
|
// 1. Depending on the shape model, we calculate the refracted point in world space and the optical depth
|
|
// 2. We calculate the screen space position of the refracted point
|
|
// 3. If this point is available (ie: in color buffer and point is not in front of the object)
|
|
// a. Get the corresponding color depending on the roughness from the gaussian pyramid of the color buffer
|
|
// b. Multiply by the transmittance for absorption (depends on the optical depth)
|
|
|
|
float3 refractedBackPointWS = EstimateRaycast(V, posInput, preLightData.transmissionPositionWS, preLightData.transmissionRefractV);
|
|
|
|
// Calculate screen space coordinates of refracted point in back plane
|
|
float2 refractedBackPointNDC = ComputeNormalizedDeviceCoordinates(refractedBackPointWS, UNITY_MATRIX_VP);
|
|
uint2 depthSize = uint2(_PyramidDepthMipSize.xy);
|
|
float refractedBackPointDepth = LinearEyeDepth(LOAD_TEXTURE2D_LOD(_PyramidDepthTexture, refractedBackPointNDC * depthSize, 0).r, _ZBufferParams);
|
|
|
|
// Exit if texel is out of color buffer
|
|
// Or if the texel is from an object in front of the object
|
|
if (refractedBackPointDepth < posInput.linearDepth
|
|
|| any(refractedBackPointNDC < 0.0)
|
|
|| any(refractedBackPointNDC > 1.0))
|
|
{
|
|
// Do nothing and don't update the hierarchy weight so we can fall back on refraction probe
|
|
return lighting;
|
|
}
|
|
|
|
// Map the roughness to the correct mip map level of the color pyramid
|
|
lighting.specularTransmitted = SAMPLE_TEXTURE2D_LOD(_GaussianPyramidColorTexture, s_trilinear_clamp_sampler, refractedBackPointNDC, preLightData.transmissionSSMipLevel).rgb;
|
|
|
|
// Beer-Lamber law for absorption
|
|
lighting.specularTransmitted *= preLightData.transmissionTransmittance;
|
|
|
|
float weight = 1.0;
|
|
UpdateLightingHierarchyWeights(hierarchyWeight, weight); // Shouldn't be needed, but safer in case we decide to change hierarchy priority
|
|
// We use specularFGD as an approximation of the fresnel effect (that also handle smoothness), so take the remaining for transmission
|
|
lighting.specularTransmitted *= (1.0 - preLightData.specularFGD) * weight;
|
|
#else
|
|
// No refraction, no need to go further
|
|
hierarchyWeight = 1.0;
|
|
#endif
|
|
|
|
return lighting;
|
|
}
|
|
|
|
DirectLighting EvaluateBSDF_Area(LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput,
|
|
PreLightData preLightData, LightData lightData,
|
|
BSDFData bsdfData, BakeLightingData bakeLightingData)
|
|
{
|
|
if (lightData.lightType == GPULIGHTTYPE_LINE)
|
|
{
|
|
return EvaluateBSDF_Line(lightLoopContext, V, posInput, preLightData, lightData, bsdfData, bakeLightingData);
|
|
}
|
|
else
|
|
{
|
|
return EvaluateBSDF_Rect(lightLoopContext, V, posInput, preLightData, lightData, bsdfData, bakeLightingData);
|
|
}
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// EvaluateBSDF_Env
|
|
// ----------------------------------------------------------------------------
|
|
|
|
// _preIntegratedFGD and _CubemapLD are unique for each BRDF
|
|
IndirectLighting EvaluateBSDF_Env( LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput,
|
|
PreLightData preLightData, EnvLightData lightData, BSDFData bsdfData, int envShapeType, int GPUImageBasedLightingType,
|
|
inout float hierarchyWeight)
|
|
{
|
|
IndirectLighting lighting;
|
|
ZERO_INITIALIZE(IndirectLighting, lighting);
|
|
#if !HAS_REFRACTION
|
|
if (GPUImageBasedLightingType == GPUIMAGEBASEDLIGHTINGTYPE_REFRACTION)
|
|
return lighting;
|
|
#endif
|
|
|
|
float3 envLighting = float3(0.0, 0.0, 0.0);
|
|
float3 positionWS = posInput.positionWS;
|
|
float weight = 1.0;
|
|
|
|
#ifdef LIT_DISPLAY_REFERENCE_IBL
|
|
|
|
envLighting = IntegrateSpecularGGXIBLRef(lightLoopContext, V, preLightData, lightData, bsdfData);
|
|
|
|
// TODO: Do refraction reference (is it even possible ?)
|
|
|
|
|
|
// #ifdef LIT_DIFFUSE_LAMBERT_BRDF
|
|
// envLighting += IntegrateLambertIBLRef(lightData, V, bsdfData);
|
|
// #else
|
|
// envLighting += IntegrateDisneyDiffuseIBLRef(lightLoopContext, V, preLightData, lightData, bsdfData);
|
|
// #endif
|
|
|
|
weight = 1.0;
|
|
|
|
#else
|
|
|
|
// TODO: factor this code in common, so other material authoring don't require to rewrite everything,
|
|
// TODO: test the strech from Tomasz
|
|
// float roughness = PerceptualRoughnessToRoughness(bsdfData.perceptualRoughness);
|
|
// float shrunkRoughness = AnisotropicStrechAtGrazingAngle(roughness, roughness, NdotV);
|
|
|
|
// Guideline for reflection volume: In HDRenderPipeline we separate the projection volume (the proxy of the scene) from the influence volume (what pixel on the screen is affected)
|
|
// However we add the constrain that the shape of the projection and influence volume is the same (i.e if we have a sphere shape projection volume, we have a shape influence).
|
|
// It allow to have more coherence for the dynamic if in shader code.
|
|
// Users can also chose to not have any projection, in this case we use the property minProjectionDistance to minimize code change. minProjectionDistance is set to huge number
|
|
// that simulate effect of no shape projection
|
|
|
|
float3 R = preLightData.iblDirWS;
|
|
float3 coatR = preLightData.coatIblDirWS;
|
|
|
|
if (GPUImageBasedLightingType == GPUIMAGEBASEDLIGHTINGTYPE_REFRACTION)
|
|
{
|
|
positionWS = preLightData.transmissionPositionWS;
|
|
R = preLightData.transmissionRefractV;
|
|
}
|
|
|
|
// In Unity the cubemaps are capture with the localToWorld transform of the component.
|
|
// This mean that location and orientation matter. So after intersection of proxy volume we need to convert back to world.
|
|
|
|
// CAUTION: localToWorld is the transform use to convert the cubemap capture point to world space (mean it include the offset)
|
|
// the center of the bounding box is thus in locals space: positionLS - offsetLS
|
|
// We use this formulation as it is the one of legacy unity that was using only AABB box.
|
|
float3x3 worldToLocal = transpose(float3x3(lightData.right, lightData.up, lightData.forward)); // worldToLocal assume no scaling
|
|
float3 positionLS = positionWS - lightData.positionWS;
|
|
positionLS = mul(positionLS, worldToLocal).xyz - lightData.offsetLS; // We want to calculate the intersection from the center of the bounding box.
|
|
|
|
// Note: using envShapeType instead of lightData.envShapeType allow to make compiler optimization in case the type is know (like for sky)
|
|
if (envShapeType == ENVSHAPETYPE_SPHERE)
|
|
{
|
|
// 1. First process the projection
|
|
float3 dirLS = mul(R, worldToLocal);
|
|
float sphereOuterDistance = lightData.innerDistance.x + lightData.blendDistance;
|
|
float dist = SphereRayIntersectSimple(positionLS, dirLS, sphereOuterDistance);
|
|
dist = max(dist, lightData.minProjectionDistance); // Setup projection to infinite if requested (mean no projection shape)
|
|
// We can reuse dist calculate in LS directly in WS as there is no scaling. Also the offset is already include in lightData.positionWS
|
|
R = (positionWS + dist * R) - lightData.positionWS;
|
|
|
|
// Test again for clear code
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
dirLS = mul(coatR, worldToLocal);
|
|
dist = SphereRayIntersectSimple(positionLS, dirLS, sphereOuterDistance);
|
|
coatR = (positionWS + dist * coatR) - lightData.positionWS;
|
|
}
|
|
|
|
// 2. Process the influence
|
|
float distFade = max(length(positionLS) - lightData.innerDistance.x, 0.0);
|
|
weight = saturate(1.0 - distFade / max(lightData.blendDistance, 0.0001)); // avoid divide by zero
|
|
}
|
|
else if (envShapeType == ENVSHAPETYPE_BOX)
|
|
{
|
|
float3 dirLS = mul(R, worldToLocal);
|
|
float3 boxOuterDistance = lightData.innerDistance + float3(lightData.blendDistance, lightData.blendDistance, lightData.blendDistance);
|
|
float dist = BoxRayIntersectSimple(positionLS, dirLS, -boxOuterDistance, boxOuterDistance);
|
|
dist = max(dist, lightData.minProjectionDistance); // Setup projection to infinite if requested (mean no projection shape)
|
|
// No need to normalize for fetching cubemap
|
|
// We can reuse dist calculate in LS directly in WS as there is no scaling. Also the offset is already include in lightData.positionWS
|
|
R = (positionWS + dist * R) - lightData.positionWS;
|
|
|
|
// TODO: add distance based roughness
|
|
|
|
// Test again for clear code
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
dirLS = mul(coatR, worldToLocal);
|
|
dist = BoxRayIntersectSimple(positionLS, dirLS, -boxOuterDistance, boxOuterDistance);
|
|
coatR = (positionWS + dist * coatR) - lightData.positionWS;
|
|
}
|
|
|
|
// Influence volume
|
|
// Calculate falloff value, so reflections on the edges of the volume would gradually blend to previous reflection.
|
|
float distFade = DistancePointBox(positionLS, -lightData.innerDistance, lightData.innerDistance);
|
|
weight = saturate(1.0 - distFade / max(lightData.blendDistance, 0.0001)); // avoid divide by zero
|
|
}
|
|
|
|
// Smooth weighting
|
|
weight = Smoothstep01(weight);
|
|
|
|
float3 F = 1.0;
|
|
|
|
// Evaluate the Clear Coat component if needed and change the BSDF roughness to match Fresnel transmission
|
|
if (bsdfData.materialId == MATERIALID_LIT_CLEAR_COAT && HasMaterialFeatureFlag(MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
|
|
{
|
|
F = F_Schlick(preLightData.coatFresnel0, preLightData.coatNdotV);
|
|
|
|
// Evaluate the Clear Coat color
|
|
float4 preLD = SampleEnv(lightLoopContext, lightData.envIndex, coatR, 0.0);
|
|
envLighting += F * preLD.rgb * bsdfData.coatCoverage;
|
|
|
|
// Change the Fresnel term to account for transmission through Clear Coat and reflection on the base layer.
|
|
F = Sq(-F * bsdfData.coatCoverage + 1.0);
|
|
}
|
|
|
|
// When we are rough, we tend to see outward shifting of the reflection when at the boundary of the projection volume
|
|
// Also it appear like more sharp. To avoid these artifact and at the same time get better match to reference we lerp to original unmodified reflection.
|
|
// Formula is empirical.
|
|
float roughness = PerceptualRoughnessToRoughness(bsdfData.perceptualRoughness);
|
|
R = lerp(R, preLightData.iblDirWS, saturate(smoothstep(0, 1, roughness * roughness)));
|
|
|
|
float4 preLD = SampleEnv(lightLoopContext, lightData.envIndex, R, preLightData.iblMipLevel);
|
|
envLighting += F * preLD.rgb;
|
|
|
|
#endif
|
|
|
|
UpdateLightingHierarchyWeights(hierarchyWeight, weight);
|
|
envLighting *= weight * lightData.dimmer;
|
|
|
|
if (GPUImageBasedLightingType == GPUIMAGEBASEDLIGHTINGTYPE_REFLECTION)
|
|
lighting.specularReflected = envLighting * preLightData.specularFGD;
|
|
else
|
|
// specular transmisted lighting is the remaining of the reflection (let's use this approx)
|
|
lighting.specularTransmitted = (1.0 - preLightData.specularFGD) * envLighting * preLightData.transmissionTransmittance;
|
|
|
|
return lighting;
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// PostEvaluateBSDF
|
|
// ----------------------------------------------------------------------------
|
|
|
|
void PostEvaluateBSDF( LightLoopContext lightLoopContext,
|
|
float3 V, PositionInputs posInput,
|
|
PreLightData preLightData, BSDFData bsdfData, BakeLightingData bakeLightingData, AggregateLighting lighting,
|
|
out float3 diffuseLighting, out float3 specularLighting)
|
|
{
|
|
float3 bakeDiffuseLighting = bakeLightingData.bakeDiffuseLighting;
|
|
|
|
// Use GTAOMultiBounce approximation for ambient occlusion (allow to get a tint from the baseColor)
|
|
#define GTAO_MULTIBOUNCE_APPROX 1
|
|
|
|
// Note: When we ImageLoad outside of texture size, the value returned by Load is 0 (Note: On Metal maybe it clamp to value of texture which is also fine)
|
|
// We use this property to have a neutral value for AO that doesn't consume a sampler and work also with compute shader (i.e use ImageLoad)
|
|
// We store inverse AO so neutral is black. So either we sample inside or outside the texture it return 0 in case of neutral
|
|
|
|
// Ambient occlusion use for indirect lighting (reflection probe, baked diffuse lighting)
|
|
#ifndef _SURFACE_TYPE_TRANSPARENT
|
|
float indirectAmbientOcclusion = 1.0 - LOAD_TEXTURE2D(_AmbientOcclusionTexture, posInput.positionSS).x;
|
|
// Ambient occlusion use for direct lighting (directional, punctual, area)
|
|
float directAmbientOcclusion = lerp(1.0, indirectAmbientOcclusion, _AmbientOcclusionParam.w);
|
|
#else
|
|
float indirectAmbientOcclusion = 1.0;
|
|
float directAmbientOcclusion = 1.0;
|
|
#endif
|
|
|
|
// Add indirect diffuse + emissive (if any) - Ambient occlusion is multiply by emissive which is wrong but not a big deal
|
|
#if GTAO_MULTIBOUNCE_APPROX
|
|
bakeDiffuseLighting *= GTAOMultiBounce(indirectAmbientOcclusion, bsdfData.diffuseColor);
|
|
#else
|
|
bakeDiffuseLighting *= lerp(_AmbientOcclusionParam.rgb, float3(1.0, 1.0, 1.0), indirectAmbientOcclusion);
|
|
#endif
|
|
|
|
float roughness = PerceptualRoughnessToRoughness(bsdfData.perceptualRoughness);
|
|
float specularOcclusion = GetSpecularOcclusionFromAmbientOcclusion(preLightData.NdotV, indirectAmbientOcclusion, roughness);
|
|
// Try to mimic multibounce with specular color. Not the point of the original formula but ok result.
|
|
// Take the min of screenspace specular occlusion and visibility cone specular occlusion
|
|
#if GTAO_MULTIBOUNCE_APPROX
|
|
lighting.indirect.specularReflected *= GTAOMultiBounce(min(bsdfData.specularOcclusion, specularOcclusion), bsdfData.fresnel0);
|
|
#else
|
|
lighting.indirect.specularReflected *= lerp(_AmbientOcclusionParam.rgb, float3(1.0, 1.0, 1.0), min(bsdfData.specularOcclusion, specularOcclusion));
|
|
#endif
|
|
|
|
lighting.direct.diffuse *=
|
|
#if GTAO_MULTIBOUNCE_APPROX
|
|
GTAOMultiBounce(directAmbientOcclusion, bsdfData.diffuseColor);
|
|
#else
|
|
lerp(_AmbientOcclusionParam.rgb, float3(1.0, 1.0, 1.0), directAmbientOcclusion);
|
|
#endif
|
|
|
|
float3 modifiedDiffuseColor;
|
|
if (bsdfData.materialId == MATERIALID_LIT_SSS)
|
|
modifiedDiffuseColor = ApplyDiffuseTexturingMode(bsdfData.diffuseColor, bsdfData.subsurfaceProfile);
|
|
else
|
|
modifiedDiffuseColor = bsdfData.diffuseColor;
|
|
|
|
// Apply the albedo to the direct diffuse lighting (only once). The indirect (baked)
|
|
// diffuse lighting has already had the albedo applied in GetBakedDiffuseLigthing().
|
|
diffuseLighting = modifiedDiffuseColor * lighting.direct.diffuse + bakeDiffuseLighting;
|
|
|
|
// If refraction is enable we use the transmittanceMask to lerp between current diffuse lighting and refraction value
|
|
// Physically speaking, it should be transmittanceMask should be 1, but for artistic reasons, we let the value vary
|
|
#if HAS_REFRACTION
|
|
diffuseLighting = lerp(diffuseLighting, lighting.indirect.specularTransmitted, bsdfData.transmittanceMask);
|
|
#endif
|
|
|
|
specularLighting = lighting.direct.specular + lighting.indirect.specularReflected;
|
|
// Rescale the GGX to account for the multiple scattering.
|
|
specularLighting *= 1.0 + bsdfData.fresnel0 * preLightData.energyCompensation;
|
|
|
|
#ifdef DEBUG_DISPLAY
|
|
if (_DebugLightingMode == DEBUGLIGHTINGMODE_INDIRECT_DIFFUSE_OCCLUSION_FROM_SSAO)
|
|
{
|
|
diffuseLighting = indirectAmbientOcclusion;
|
|
specularLighting = float3(0.0, 0.0, 0.0); // Disable specular lighting
|
|
}
|
|
else if (_DebugLightingMode == DEBUGLIGHTINGMODE_INDIRECT_SPECULAR_OCCLUSION_FROM_SSAO)
|
|
{
|
|
diffuseLighting = specularOcclusion;
|
|
specularLighting = float3(0.0, 0.0, 0.0); // Disable specular lighting
|
|
}
|
|
#if GTAO_MULTIBOUNCE_APPROX
|
|
else if (_DebugLightingMode == DEBUGLIGHTINGMODE_INDIRECT_DIFFUSE_GTAO_FROM_SSAO)
|
|
{
|
|
diffuseLighting = GTAOMultiBounce(indirectAmbientOcclusion, bsdfData.diffuseColor);
|
|
specularLighting = float3(0.0, 0.0, 0.0); // Disable specular lighting
|
|
}
|
|
else if (_DebugLightingMode == DEBUGLIGHTINGMODE_INDIRECT_SPECULAR_GTAO_FROM_SSAO)
|
|
{
|
|
diffuseLighting = GTAOMultiBounce(specularOcclusion, bsdfData.fresnel0);
|
|
specularLighting = float3(0.0, 0.0, 0.0); // Disable specular lighting
|
|
}
|
|
#endif
|
|
#endif
|
|
}
|
|
|
|
#endif // #ifdef HAS_LIGHTLOOP
|