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PixelJumperHero/Library/PackageCache/com.unity.render-pipelines.universal@11.0.0/ShaderLibrary/Lighting.hlsl
BRNSystems df2d24cbd3 testss
2021-06-13 10:28:03 +02:00

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#ifndef UNIVERSAL_LIGHTING_INCLUDED
#define UNIVERSAL_LIGHTING_INCLUDED
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/CommonMaterial.hlsl"
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/EntityLighting.hlsl"
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/ImageBasedLighting.hlsl"
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/BSDF.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Deprecated.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/SurfaceData.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Shadows.hlsl"
// If lightmap is not defined than we evaluate GI (ambient + probes) from SH
// We might do it fully or partially in vertex to save shader ALU
#if !defined(LIGHTMAP_ON)
// TODO: Controls things like these by exposing SHADER_QUALITY levels (low, medium, high)
#if defined(SHADER_API_GLES) || !defined(_NORMALMAP)
// Evaluates SH fully in vertex
#define EVALUATE_SH_VERTEX
#elif !SHADER_HINT_NICE_QUALITY
// Evaluates L2 SH in vertex and L0L1 in pixel
#define EVALUATE_SH_MIXED
#endif
// Otherwise evaluate SH fully per-pixel
#endif
#ifdef LIGHTMAP_ON
#define DECLARE_LIGHTMAP_OR_SH(lmName, shName, index) float2 lmName : TEXCOORD##index
#define OUTPUT_LIGHTMAP_UV(lightmapUV, lightmapScaleOffset, OUT) OUT.xy = lightmapUV.xy * lightmapScaleOffset.xy + lightmapScaleOffset.zw;
#define OUTPUT_SH(normalWS, OUT)
#else
#define DECLARE_LIGHTMAP_OR_SH(lmName, shName, index) half3 shName : TEXCOORD##index
#define OUTPUT_LIGHTMAP_UV(lightmapUV, lightmapScaleOffset, OUT)
#define OUTPUT_SH(normalWS, OUT) OUT.xyz = SampleSHVertex(normalWS)
#endif
// Renamed -> LIGHTMAP_SHADOW_MIXING
#if !defined(_MIXED_LIGHTING_SUBTRACTIVE) && defined(LIGHTMAP_SHADOW_MIXING) && !defined(SHADOWS_SHADOWMASK)
#define _MIXED_LIGHTING_SUBTRACTIVE
#endif
///////////////////////////////////////////////////////////////////////////////
// Light Helpers //
///////////////////////////////////////////////////////////////////////////////
// Abstraction over Light shading data.
struct Light
{
half3 direction;
half3 color;
half distanceAttenuation;
half shadowAttenuation;
};
///////////////////////////////////////////////////////////////////////////////
// Attenuation Functions /
///////////////////////////////////////////////////////////////////////////////
// Matches Unity Vanila attenuation
// Attenuation smoothly decreases to light range.
float DistanceAttenuation(float distanceSqr, half2 distanceAttenuation)
{
// We use a shared distance attenuation for additional directional and puctual lights
// for directional lights attenuation will be 1
float lightAtten = rcp(distanceSqr);
#if SHADER_HINT_NICE_QUALITY
// Use the smoothing factor also used in the Unity lightmapper.
half factor = distanceSqr * distanceAttenuation.x;
half smoothFactor = saturate(1.0h - factor * factor);
smoothFactor = smoothFactor * smoothFactor;
#else
// We need to smoothly fade attenuation to light range. We start fading linearly at 80% of light range
// Therefore:
// fadeDistance = (0.8 * 0.8 * lightRangeSq)
// smoothFactor = (lightRangeSqr - distanceSqr) / (lightRangeSqr - fadeDistance)
// We can rewrite that to fit a MAD by doing
// distanceSqr * (1.0 / (fadeDistanceSqr - lightRangeSqr)) + (-lightRangeSqr / (fadeDistanceSqr - lightRangeSqr)
// distanceSqr * distanceAttenuation.y + distanceAttenuation.z
half smoothFactor = saturate(distanceSqr * distanceAttenuation.x + distanceAttenuation.y);
#endif
return lightAtten * smoothFactor;
}
half AngleAttenuation(half3 spotDirection, half3 lightDirection, half2 spotAttenuation)
{
// Spot Attenuation with a linear falloff can be defined as
// (SdotL - cosOuterAngle) / (cosInnerAngle - cosOuterAngle)
// This can be rewritten as
// invAngleRange = 1.0 / (cosInnerAngle - cosOuterAngle)
// SdotL * invAngleRange + (-cosOuterAngle * invAngleRange)
// SdotL * spotAttenuation.x + spotAttenuation.y
// If we precompute the terms in a MAD instruction
half SdotL = dot(spotDirection, lightDirection);
half atten = saturate(SdotL * spotAttenuation.x + spotAttenuation.y);
return atten * atten;
}
///////////////////////////////////////////////////////////////////////////////
// Light Abstraction //
///////////////////////////////////////////////////////////////////////////////
Light GetMainLight()
{
Light light;
light.direction = _MainLightPosition.xyz;
light.distanceAttenuation = unity_LightData.z; // unity_LightData.z is 1 when not culled by the culling mask, otherwise 0.
light.shadowAttenuation = 1.0;
light.color = _MainLightColor.rgb;
return light;
}
Light GetMainLight(float4 shadowCoord)
{
Light light = GetMainLight();
light.shadowAttenuation = MainLightRealtimeShadow(shadowCoord);
return light;
}
Light GetMainLight(float4 shadowCoord, float3 positionWS, half4 shadowMask)
{
Light light = GetMainLight();
light.shadowAttenuation = MainLightShadow(shadowCoord, positionWS, shadowMask, _MainLightOcclusionProbes);
return light;
}
// Fills a light struct given a perObjectLightIndex
Light GetAdditionalPerObjectLight(int perObjectLightIndex, float3 positionWS)
{
// Abstraction over Light input constants
#if USE_STRUCTURED_BUFFER_FOR_LIGHT_DATA
float4 lightPositionWS = _AdditionalLightsBuffer[perObjectLightIndex].position;
half3 color = _AdditionalLightsBuffer[perObjectLightIndex].color.rgb;
half4 distanceAndSpotAttenuation = _AdditionalLightsBuffer[perObjectLightIndex].attenuation;
half4 spotDirection = _AdditionalLightsBuffer[perObjectLightIndex].spotDirection;
#else
float4 lightPositionWS = _AdditionalLightsPosition[perObjectLightIndex];
half3 color = _AdditionalLightsColor[perObjectLightIndex].rgb;
half4 distanceAndSpotAttenuation = _AdditionalLightsAttenuation[perObjectLightIndex];
half4 spotDirection = _AdditionalLightsSpotDir[perObjectLightIndex];
#endif
// Directional lights store direction in lightPosition.xyz and have .w set to 0.0.
// This way the following code will work for both directional and punctual lights.
float3 lightVector = lightPositionWS.xyz - positionWS * lightPositionWS.w;
float distanceSqr = max(dot(lightVector, lightVector), HALF_MIN);
half3 lightDirection = half3(lightVector * rsqrt(distanceSqr));
half attenuation = DistanceAttenuation(distanceSqr, distanceAndSpotAttenuation.xy) * AngleAttenuation(spotDirection.xyz, lightDirection, distanceAndSpotAttenuation.zw);
Light light;
light.direction = lightDirection;
light.distanceAttenuation = attenuation;
light.shadowAttenuation = 1.0; // This value can later be overridden in GetAdditionalLight(uint i, float3 positionWS, half4 shadowMask)
light.color = color;
return light;
}
uint GetPerObjectLightIndexOffset()
{
#if USE_STRUCTURED_BUFFER_FOR_LIGHT_DATA
return unity_LightData.x;
#else
return 0;
#endif
}
// Returns a per-object index given a loop index.
// This abstract the underlying data implementation for storing lights/light indices
int GetPerObjectLightIndex(uint index)
{
/////////////////////////////////////////////////////////////////////////////////////////////
// Structured Buffer Path /
// /
// Lights and light indices are stored in StructuredBuffer. We can just index them. /
// Currently all non-mobile platforms take this path :( /
// There are limitation in mobile GPUs to use SSBO (performance / no vertex shader support) /
/////////////////////////////////////////////////////////////////////////////////////////////
#if USE_STRUCTURED_BUFFER_FOR_LIGHT_DATA
uint offset = unity_LightData.x;
return _AdditionalLightsIndices[offset + index];
/////////////////////////////////////////////////////////////////////////////////////////////
// UBO path /
// /
// We store 8 light indices in float4 unity_LightIndices[2]; /
// Due to memory alignment unity doesn't support int[] or float[] /
// Even trying to reinterpret cast the unity_LightIndices to float[] won't work /
// it will cast to float4[] and create extra register pressure. :( /
/////////////////////////////////////////////////////////////////////////////////////////////
#elif !defined(SHADER_API_GLES)
// since index is uint shader compiler will implement
// div & mod as bitfield ops (shift and mask).
// TODO: Can we index a float4? Currently compiler is
// replacing unity_LightIndicesX[i] with a dp4 with identity matrix.
// u_xlat16_40 = dot(unity_LightIndices[int(u_xlatu13)], ImmCB_0_0_0[u_xlati1]);
// This increases both arithmetic and register pressure.
return unity_LightIndices[index / 4][index % 4];
#else
// Fallback to GLES2. No bitfield magic here :(.
// We limit to 4 indices per object and only sample unity_4LightIndices0.
// Conditional moves are branch free even on mali-400
// small arithmetic cost but no extra register pressure from ImmCB_0_0_0 matrix.
half2 lightIndex2 = (index < 2.0h) ? unity_LightIndices[0].xy : unity_LightIndices[0].zw;
half i_rem = (index < 2.0h) ? index : index - 2.0h;
return (i_rem < 1.0h) ? lightIndex2.x : lightIndex2.y;
#endif
}
// Fills a light struct given a loop i index. This will convert the i
// index to a perObjectLightIndex
Light GetAdditionalLight(uint i, float3 positionWS)
{
int perObjectLightIndex = GetPerObjectLightIndex(i);
return GetAdditionalPerObjectLight(perObjectLightIndex, positionWS);
}
Light GetAdditionalLight(uint i, float3 positionWS, half4 shadowMask)
{
int perObjectLightIndex = GetPerObjectLightIndex(i);
Light light = GetAdditionalPerObjectLight(perObjectLightIndex, positionWS);
#if USE_STRUCTURED_BUFFER_FOR_LIGHT_DATA
half4 occlusionProbeChannels = _AdditionalLightsBuffer[perObjectLightIndex].occlusionProbeChannels;
#else
half4 occlusionProbeChannels = _AdditionalLightsOcclusionProbes[perObjectLightIndex];
#endif
light.shadowAttenuation = AdditionalLightShadow(perObjectLightIndex, positionWS, light.direction, shadowMask, occlusionProbeChannels);
return light;
}
int GetAdditionalLightsCount()
{
// TODO: we need to expose in SRP api an ability for the pipeline cap the amount of lights
// in the culling. This way we could do the loop branch with an uniform
// This would be helpful to support baking exceeding lights in SH as well
return min(_AdditionalLightsCount.x, unity_LightData.y);
}
///////////////////////////////////////////////////////////////////////////////
// BRDF Functions //
///////////////////////////////////////////////////////////////////////////////
#define kDielectricSpec half4(0.04, 0.04, 0.04, 1.0 - 0.04) // standard dielectric reflectivity coef at incident angle (= 4%)
struct BRDFData
{
half3 diffuse;
half3 specular;
half reflectivity;
half perceptualRoughness;
half roughness;
half roughness2;
half grazingTerm;
// We save some light invariant BRDF terms so we don't have to recompute
// them in the light loop. Take a look at DirectBRDF function for detailed explaination.
half normalizationTerm; // roughness * 4.0 + 2.0
half roughness2MinusOne; // roughness^2 - 1.0
};
half ReflectivitySpecular(half3 specular)
{
#if defined(SHADER_API_GLES)
return specular.r; // Red channel - because most metals are either monocrhome or with redish/yellowish tint
#else
return max(max(specular.r, specular.g), specular.b);
#endif
}
half OneMinusReflectivityMetallic(half metallic)
{
// We'll need oneMinusReflectivity, so
// 1-reflectivity = 1-lerp(dielectricSpec, 1, metallic) = lerp(1-dielectricSpec, 0, metallic)
// store (1-dielectricSpec) in kDielectricSpec.a, then
// 1-reflectivity = lerp(alpha, 0, metallic) = alpha + metallic*(0 - alpha) =
// = alpha - metallic * alpha
half oneMinusDielectricSpec = kDielectricSpec.a;
return oneMinusDielectricSpec - metallic * oneMinusDielectricSpec;
}
inline void InitializeBRDFDataDirect(half3 diffuse, half3 specular, half reflectivity, half oneMinusReflectivity, half smoothness, inout half alpha, out BRDFData outBRDFData)
{
outBRDFData.diffuse = diffuse;
outBRDFData.specular = specular;
outBRDFData.reflectivity = reflectivity;
outBRDFData.perceptualRoughness = PerceptualSmoothnessToPerceptualRoughness(smoothness);
outBRDFData.roughness = max(PerceptualRoughnessToRoughness(outBRDFData.perceptualRoughness), HALF_MIN_SQRT);
outBRDFData.roughness2 = max(outBRDFData.roughness * outBRDFData.roughness, HALF_MIN);
outBRDFData.grazingTerm = saturate(smoothness + reflectivity);
outBRDFData.normalizationTerm = outBRDFData.roughness * 4.0h + 2.0h;
outBRDFData.roughness2MinusOne = outBRDFData.roughness2 - 1.0h;
#ifdef _ALPHAPREMULTIPLY_ON
outBRDFData.diffuse *= alpha;
alpha = alpha * oneMinusReflectivity + reflectivity; // NOTE: alpha modified and propagated up.
#endif
}
inline void InitializeBRDFData(half3 albedo, half metallic, half3 specular, half smoothness, inout half alpha, out BRDFData outBRDFData)
{
#ifdef _SPECULAR_SETUP
half reflectivity = ReflectivitySpecular(specular);
half oneMinusReflectivity = 1.0 - reflectivity;
half3 brdfDiffuse = albedo * (half3(1.0h, 1.0h, 1.0h) - specular);
half3 brdfSpecular = specular;
#else
half oneMinusReflectivity = OneMinusReflectivityMetallic(metallic);
half reflectivity = 1.0 - oneMinusReflectivity;
half3 brdfDiffuse = albedo * oneMinusReflectivity;
half3 brdfSpecular = lerp(kDieletricSpec.rgb, albedo, metallic);
#endif
InitializeBRDFDataDirect(brdfDiffuse, brdfSpecular, reflectivity, oneMinusReflectivity, smoothness, alpha, outBRDFData);
}
half3 ConvertF0ForClearCoat15(half3 f0)
{
#if defined(SHADER_API_MOBILE)
return ConvertF0ForAirInterfaceToF0ForClearCoat15Fast(f0);
#else
return ConvertF0ForAirInterfaceToF0ForClearCoat15(f0);
#endif
}
inline void InitializeBRDFDataClearCoat(half clearCoatMask, half clearCoatSmoothness, inout BRDFData baseBRDFData, out BRDFData outBRDFData)
{
// Calculate Roughness of Clear Coat layer
outBRDFData.diffuse = kDielectricSpec.aaa; // 1 - kDielectricSpec
outBRDFData.specular = kDielectricSpec.rgb;
outBRDFData.reflectivity = kDielectricSpec.r;
outBRDFData.perceptualRoughness = PerceptualSmoothnessToPerceptualRoughness(clearCoatSmoothness);
outBRDFData.roughness = max(PerceptualRoughnessToRoughness(outBRDFData.perceptualRoughness), HALF_MIN_SQRT);
outBRDFData.roughness2 = max(outBRDFData.roughness * outBRDFData.roughness, HALF_MIN);
outBRDFData.normalizationTerm = outBRDFData.roughness * 4.0h + 2.0h;
outBRDFData.roughness2MinusOne = outBRDFData.roughness2 - 1.0h;
outBRDFData.grazingTerm = saturate(clearCoatSmoothness + kDielectricSpec.x);
// Relatively small effect, cut it for lower quality
#if !defined(SHADER_API_MOBILE)
// Modify Roughness of base layer using coat IOR
half ieta = lerp(1.0h, CLEAR_COAT_IETA, clearCoatMask);
half coatRoughnessScale = Sq(ieta);
half sigma = RoughnessToVariance(PerceptualRoughnessToRoughness(baseBRDFData.perceptualRoughness));
baseBRDFData.perceptualRoughness = RoughnessToPerceptualRoughness(VarianceToRoughness(sigma * coatRoughnessScale));
// Recompute base material for new roughness, previous computation should be eliminated by the compiler (as it's unused)
baseBRDFData.roughness = max(PerceptualRoughnessToRoughness(baseBRDFData.perceptualRoughness), HALF_MIN_SQRT);
baseBRDFData.roughness2 = max(baseBRDFData.roughness * baseBRDFData.roughness, HALF_MIN);
baseBRDFData.normalizationTerm = baseBRDFData.roughness * 4.0h + 2.0h;
baseBRDFData.roughness2MinusOne = baseBRDFData.roughness2 - 1.0h;
#endif
// Darken/saturate base layer using coat to surface reflectance (vs. air to surface)
baseBRDFData.specular = lerp(baseBRDFData.specular, ConvertF0ForClearCoat15(baseBRDFData.specular), clearCoatMask);
// TODO: what about diffuse? at least in specular workflow diffuse should be recalculated as it directly depends on it.
}
// Computes the specular term for EnvironmentBRDF
half3 EnvironmentBRDFSpecular(BRDFData brdfData, half fresnelTerm)
{
float surfaceReduction = 1.0 / (brdfData.roughness2 + 1.0);
return surfaceReduction * lerp(brdfData.specular, brdfData.grazingTerm, fresnelTerm);
}
half3 EnvironmentBRDF(BRDFData brdfData, half3 indirectDiffuse, half3 indirectSpecular, half fresnelTerm)
{
half3 c = indirectDiffuse * brdfData.diffuse;
c += indirectSpecular * EnvironmentBRDFSpecular(brdfData, fresnelTerm);
return c;
}
// Environment BRDF without diffuse for clear coat
half3 EnvironmentBRDFClearCoat(BRDFData brdfData, half clearCoatMask, half3 indirectSpecular, half fresnelTerm)
{
float surfaceReduction = 1.0 / (brdfData.roughness2 + 1.0);
return indirectSpecular * EnvironmentBRDFSpecular(brdfData, fresnelTerm) * clearCoatMask;
}
// Computes the scalar specular term for Minimalist CookTorrance BRDF
// NOTE: needs to be multiplied with reflectance f0, i.e. specular color to complete
half DirectBRDFSpecular(BRDFData brdfData, half3 normalWS, half3 lightDirectionWS, half3 viewDirectionWS)
{
float3 halfDir = SafeNormalize(float3(lightDirectionWS) + float3(viewDirectionWS));
float NoH = saturate(dot(normalWS, halfDir));
half LoH = saturate(dot(lightDirectionWS, halfDir));
// GGX Distribution multiplied by combined approximation of Visibility and Fresnel
// BRDFspec = (D * V * F) / 4.0
// D = roughness^2 / ( NoH^2 * (roughness^2 - 1) + 1 )^2
// V * F = 1.0 / ( LoH^2 * (roughness + 0.5) )
// See "Optimizing PBR for Mobile" from Siggraph 2015 moving mobile graphics course
// https://community.arm.com/events/1155
// Final BRDFspec = roughness^2 / ( NoH^2 * (roughness^2 - 1) + 1 )^2 * (LoH^2 * (roughness + 0.5) * 4.0)
// We further optimize a few light invariant terms
// brdfData.normalizationTerm = (roughness + 0.5) * 4.0 rewritten as roughness * 4.0 + 2.0 to a fit a MAD.
float d = NoH * NoH * brdfData.roughness2MinusOne + 1.00001f;
half LoH2 = LoH * LoH;
half specularTerm = brdfData.roughness2 / ((d * d) * max(0.1h, LoH2) * brdfData.normalizationTerm);
// On platforms where half actually means something, the denominator has a risk of overflow
// clamp below was added specifically to "fix" that, but dx compiler (we convert bytecode to metal/gles)
// sees that specularTerm have only non-negative terms, so it skips max(0,..) in clamp (leaving only min(100,...))
#if defined (SHADER_API_MOBILE) || defined (SHADER_API_SWITCH)
specularTerm = specularTerm - HALF_MIN;
specularTerm = clamp(specularTerm, 0.0, 100.0); // Prevent FP16 overflow on mobiles
#endif
return specularTerm;
}
// Based on Minimalist CookTorrance BRDF
// Implementation is slightly different from original derivation: http://www.thetenthplanet.de/archives/255
//
// * NDF [Modified] GGX
// * Modified Kelemen and Szirmay-Kalos for Visibility term
// * Fresnel approximated with 1/LdotH
half3 DirectBDRF(BRDFData brdfData, half3 normalWS, half3 lightDirectionWS, half3 viewDirectionWS, bool specularHighlightsOff)
{
// Can still do compile-time optimisation.
// If no compile-time optimized, extra overhead if branch taken is around +2.5% on Switch, -10% if not taken.
[branch] if (!specularHighlightsOff)
{
half specularTerm = DirectBRDFSpecular(brdfData, normalWS, lightDirectionWS, viewDirectionWS);
half3 color = brdfData.diffuse + specularTerm * brdfData.specular;
return color;
}
else
return brdfData.diffuse;
}
// Based on Minimalist CookTorrance BRDF
// Implementation is slightly different from original derivation: http://www.thetenthplanet.de/archives/255
//
// * NDF [Modified] GGX
// * Modified Kelemen and Szirmay-Kalos for Visibility term
// * Fresnel approximated with 1/LdotH
half3 DirectBRDF(BRDFData brdfData, half3 normalWS, half3 lightDirectionWS, half3 viewDirectionWS)
{
#ifndef _SPECULARHIGHLIGHTS_OFF
return brdfData.diffuse + DirectBRDFSpecular(brdfData, normalWS, lightDirectionWS, viewDirectionWS) * brdfData.specular;
#else
return brdfData.diffuse;
#endif
}
///////////////////////////////////////////////////////////////////////////////
// Global Illumination //
///////////////////////////////////////////////////////////////////////////////
// Ambient occlusion
TEXTURE2D_X(_ScreenSpaceOcclusionTexture);
SAMPLER(sampler_ScreenSpaceOcclusionTexture);
struct AmbientOcclusionFactor
{
half indirectAmbientOcclusion;
half directAmbientOcclusion;
};
half SampleAmbientOcclusion(float2 normalizedScreenSpaceUV)
{
float2 uv = UnityStereoTransformScreenSpaceTex(normalizedScreenSpaceUV);
return SAMPLE_TEXTURE2D_X(_ScreenSpaceOcclusionTexture, sampler_ScreenSpaceOcclusionTexture, uv).x;
}
AmbientOcclusionFactor GetScreenSpaceAmbientOcclusion(float2 normalizedScreenSpaceUV)
{
AmbientOcclusionFactor aoFactor;
aoFactor.indirectAmbientOcclusion = SampleAmbientOcclusion(normalizedScreenSpaceUV);
aoFactor.directAmbientOcclusion = lerp(1.0, aoFactor.indirectAmbientOcclusion, _AmbientOcclusionParam.w);
return aoFactor;
}
// Samples SH L0, L1 and L2 terms
half3 SampleSH(half3 normalWS)
{
// LPPV is not supported in Ligthweight Pipeline
real4 SHCoefficients[7];
SHCoefficients[0] = unity_SHAr;
SHCoefficients[1] = unity_SHAg;
SHCoefficients[2] = unity_SHAb;
SHCoefficients[3] = unity_SHBr;
SHCoefficients[4] = unity_SHBg;
SHCoefficients[5] = unity_SHBb;
SHCoefficients[6] = unity_SHC;
return max(half3(0, 0, 0), SampleSH9(SHCoefficients, normalWS));
}
// SH Vertex Evaluation. Depending on target SH sampling might be
// done completely per vertex or mixed with L2 term per vertex and L0, L1
// per pixel. See SampleSHPixel
half3 SampleSHVertex(half3 normalWS)
{
#if defined(EVALUATE_SH_VERTEX)
return SampleSH(normalWS);
#elif defined(EVALUATE_SH_MIXED)
// no max since this is only L2 contribution
return SHEvalLinearL2(normalWS, unity_SHBr, unity_SHBg, unity_SHBb, unity_SHC);
#endif
// Fully per-pixel. Nothing to compute.
return half3(0.0, 0.0, 0.0);
}
// SH Pixel Evaluation. Depending on target SH sampling might be done
// mixed or fully in pixel. See SampleSHVertex
half3 SampleSHPixel(half3 L2Term, half3 normalWS)
{
#if defined(EVALUATE_SH_VERTEX)
return L2Term;
#elif defined(EVALUATE_SH_MIXED)
half3 L0L1Term = SHEvalLinearL0L1(normalWS, unity_SHAr, unity_SHAg, unity_SHAb);
half3 res = L2Term + L0L1Term;
#ifdef UNITY_COLORSPACE_GAMMA
res = LinearToSRGB(res);
#endif
return max(half3(0, 0, 0), res);
#endif
// Default: Evaluate SH fully per-pixel
return SampleSH(normalWS);
}
#if defined(UNITY_DOTS_INSTANCING_ENABLED)
#define LIGHTMAP_NAME unity_Lightmaps
#define LIGHTMAP_INDIRECTION_NAME unity_LightmapsInd
#define LIGHTMAP_SAMPLER_NAME samplerunity_Lightmaps
#define LIGHTMAP_SAMPLE_EXTRA_ARGS lightmapUV, unity_LightmapIndex.x
#else
#define LIGHTMAP_NAME unity_Lightmap
#define LIGHTMAP_INDIRECTION_NAME unity_LightmapInd
#define LIGHTMAP_SAMPLER_NAME samplerunity_Lightmap
#define LIGHTMAP_SAMPLE_EXTRA_ARGS lightmapUV
#endif
// Sample baked lightmap. Non-Direction and Directional if available.
// Realtime GI is not supported.
half3 SampleLightmap(float2 lightmapUV, half3 normalWS)
{
#ifdef UNITY_LIGHTMAP_FULL_HDR
bool encodedLightmap = false;
#else
bool encodedLightmap = true;
#endif
half4 decodeInstructions = half4(LIGHTMAP_HDR_MULTIPLIER, LIGHTMAP_HDR_EXPONENT, 0.0h, 0.0h);
// The shader library sample lightmap functions transform the lightmap uv coords to apply bias and scale.
// However, universal pipeline already transformed those coords in vertex. We pass half4(1, 1, 0, 0) and
// the compiler will optimize the transform away.
half4 transformCoords = half4(1, 1, 0, 0);
#if defined(LIGHTMAP_ON) && defined(DIRLIGHTMAP_COMBINED)
return SampleDirectionalLightmap(TEXTURE2D_LIGHTMAP_ARGS(LIGHTMAP_NAME, LIGHTMAP_SAMPLER_NAME),
TEXTURE2D_LIGHTMAP_ARGS(LIGHTMAP_INDIRECTION_NAME, LIGHTMAP_SAMPLER_NAME),
LIGHTMAP_SAMPLE_EXTRA_ARGS, transformCoords, normalWS, encodedLightmap, decodeInstructions);
#elif defined(LIGHTMAP_ON)
return SampleSingleLightmap(TEXTURE2D_LIGHTMAP_ARGS(LIGHTMAP_NAME, LIGHTMAP_SAMPLER_NAME), LIGHTMAP_SAMPLE_EXTRA_ARGS, transformCoords, encodedLightmap, decodeInstructions);
#else
return half3(0.0, 0.0, 0.0);
#endif
}
// We either sample GI from baked lightmap or from probes.
// If lightmap: sampleData.xy = lightmapUV
// If probe: sampleData.xyz = L2 SH terms
#if defined(LIGHTMAP_ON)
#define SAMPLE_GI(lmName, shName, normalWSName) SampleLightmap(lmName, normalWSName)
#else
#define SAMPLE_GI(lmName, shName, normalWSName) SampleSHPixel(shName, normalWSName)
#endif
half3 GlossyEnvironmentReflection(half3 reflectVector, half perceptualRoughness, half occlusion)
{
#if !defined(_ENVIRONMENTREFLECTIONS_OFF)
half mip = PerceptualRoughnessToMipmapLevel(perceptualRoughness);
half4 encodedIrradiance = SAMPLE_TEXTURECUBE_LOD(unity_SpecCube0, samplerunity_SpecCube0, reflectVector, mip);
//TODO:DOTS - we need to port probes to live in c# so we can manage this manually.
#if defined(UNITY_USE_NATIVE_HDR) || defined(UNITY_DOTS_INSTANCING_ENABLED)
half3 irradiance = encodedIrradiance.rgb;
#else
half3 irradiance = DecodeHDREnvironment(encodedIrradiance, unity_SpecCube0_HDR);
#endif
return irradiance * occlusion;
#endif // GLOSSY_REFLECTIONS
return _GlossyEnvironmentColor.rgb * occlusion;
}
half3 SubtractDirectMainLightFromLightmap(Light mainLight, half3 normalWS, half3 bakedGI)
{
// Let's try to make realtime shadows work on a surface, which already contains
// baked lighting and shadowing from the main sun light.
// Summary:
// 1) Calculate possible value in the shadow by subtracting estimated light contribution from the places occluded by realtime shadow:
// a) preserves other baked lights and light bounces
// b) eliminates shadows on the geometry facing away from the light
// 2) Clamp against user defined ShadowColor.
// 3) Pick original lightmap value, if it is the darkest one.
// 1) Gives good estimate of illumination as if light would've been shadowed during the bake.
// We only subtract the main direction light. This is accounted in the contribution term below.
half shadowStrength = GetMainLightShadowStrength();
half contributionTerm = saturate(dot(mainLight.direction, normalWS));
half3 lambert = mainLight.color * contributionTerm;
half3 estimatedLightContributionMaskedByInverseOfShadow = lambert * (1.0 - mainLight.shadowAttenuation);
half3 subtractedLightmap = bakedGI - estimatedLightContributionMaskedByInverseOfShadow;
// 2) Allows user to define overall ambient of the scene and control situation when realtime shadow becomes too dark.
half3 realtimeShadow = max(subtractedLightmap, _SubtractiveShadowColor.xyz);
realtimeShadow = lerp(bakedGI, realtimeShadow, shadowStrength);
// 3) Pick darkest color
return min(bakedGI, realtimeShadow);
}
half3 GlobalIllumination(BRDFData brdfData, BRDFData brdfDataClearCoat, float clearCoatMask,
half3 bakedGI, half occlusion,
half3 normalWS, half3 viewDirectionWS)
{
half3 reflectVector = reflect(-viewDirectionWS, normalWS);
half NoV = saturate(dot(normalWS, viewDirectionWS));
half fresnelTerm = Pow4(1.0 - NoV);
half3 indirectDiffuse = bakedGI * occlusion;
half3 indirectSpecular = GlossyEnvironmentReflection(reflectVector, brdfData.perceptualRoughness, occlusion);
half3 color = EnvironmentBRDF(brdfData, indirectDiffuse, indirectSpecular, fresnelTerm);
#if defined(_CLEARCOAT) || defined(_CLEARCOATMAP)
half3 coatIndirectSpecular = GlossyEnvironmentReflection(reflectVector, brdfDataClearCoat.perceptualRoughness, occlusion);
// TODO: "grazing term" causes problems on full roughness
half3 coatColor = EnvironmentBRDFClearCoat(brdfDataClearCoat, clearCoatMask, coatIndirectSpecular, fresnelTerm);
// Blend with base layer using khronos glTF recommended way using NoV
// Smooth surface & "ambiguous" lighting
// NOTE: fresnelTerm (above) is pow4 instead of pow5, but should be ok as blend weight.
half coatFresnel = kDielectricSpec.x + kDielectricSpec.a * fresnelTerm;
return color * (1.0 - coatFresnel * clearCoatMask) + coatColor;
#else
return color;
#endif
}
// Backwards compatiblity
half3 GlobalIllumination(BRDFData brdfData, half3 bakedGI, half occlusion, half3 normalWS, half3 viewDirectionWS)
{
const BRDFData noClearCoat = (BRDFData)0;
return GlobalIllumination(brdfData, noClearCoat, 0.0, bakedGI, occlusion, normalWS, viewDirectionWS);
}
void MixRealtimeAndBakedGI(inout Light light, half3 normalWS, inout half3 bakedGI)
{
#if defined(LIGHTMAP_ON) && defined(_MIXED_LIGHTING_SUBTRACTIVE)
bakedGI = SubtractDirectMainLightFromLightmap(light, normalWS, bakedGI);
#endif
}
// Backwards compatiblity
void MixRealtimeAndBakedGI(inout Light light, half3 normalWS, inout half3 bakedGI, half4 shadowMask)
{
MixRealtimeAndBakedGI(light, normalWS, bakedGI);
}
///////////////////////////////////////////////////////////////////////////////
// Lighting Functions //
///////////////////////////////////////////////////////////////////////////////
half3 LightingLambert(half3 lightColor, half3 lightDir, half3 normal)
{
half NdotL = saturate(dot(normal, lightDir));
return lightColor * NdotL;
}
half3 LightingSpecular(half3 lightColor, half3 lightDir, half3 normal, half3 viewDir, half4 specular, half smoothness)
{
float3 halfVec = SafeNormalize(float3(lightDir) + float3(viewDir));
half NdotH = saturate(dot(normal, halfVec));
half modifier = pow(NdotH, smoothness);
half3 specularReflection = specular.rgb * modifier;
return lightColor * specularReflection;
}
half3 LightingPhysicallyBased(BRDFData brdfData, BRDFData brdfDataClearCoat,
half3 lightColor, half3 lightDirectionWS, half lightAttenuation,
half3 normalWS, half3 viewDirectionWS,
half clearCoatMask, bool specularHighlightsOff)
{
half NdotL = saturate(dot(normalWS, lightDirectionWS));
half3 radiance = lightColor * (lightAttenuation * NdotL);
half3 brdf = brdfData.diffuse;
#ifndef _SPECULARHIGHLIGHTS_OFF
[branch] if (!specularHighlightsOff)
{
brdf += brdfData.specular * DirectBRDFSpecular(brdfData, normalWS, lightDirectionWS, viewDirectionWS);
#if defined(_CLEARCOAT) || defined(_CLEARCOATMAP)
// Clear coat evaluates the specular a second timw and has some common terms with the base specular.
// We rely on the compiler to merge these and compute them only once.
half brdfCoat = kDielectricSpec.r * DirectBRDFSpecular(brdfDataClearCoat, normalWS, lightDirectionWS, viewDirectionWS);
// Mix clear coat and base layer using khronos glTF recommended formula
// https://github.com/KhronosGroup/glTF/blob/master/extensions/2.0/Khronos/KHR_materials_clearcoat/README.md
// Use NoV for direct too instead of LoH as an optimization (NoV is light invariant).
half NoV = saturate(dot(normalWS, viewDirectionWS));
// Use slightly simpler fresnelTerm (Pow4 vs Pow5) as a small optimization.
// It is matching fresnel used in the GI/Env, so should produce a consistent clear coat blend (env vs. direct)
half coatFresnel = kDielectricSpec.x + kDielectricSpec.a * Pow4(1.0 - NoV);
brdf = brdf * (1.0 - clearCoatMask * coatFresnel) + brdfCoat * clearCoatMask;
#endif // _CLEARCOAT
}
#endif // _SPECULARHIGHLIGHTS_OFF
return brdf * radiance;
}
half3 LightingPhysicallyBased(BRDFData brdfData, BRDFData brdfDataClearCoat, Light light, half3 normalWS, half3 viewDirectionWS, half clearCoatMask, bool specularHighlightsOff)
{
return LightingPhysicallyBased(brdfData, brdfDataClearCoat, light.color, light.direction, light.distanceAttenuation * light.shadowAttenuation, normalWS, viewDirectionWS, clearCoatMask, specularHighlightsOff);
}
// Backwards compatibility
half3 LightingPhysicallyBased(BRDFData brdfData, Light light, half3 normalWS, half3 viewDirectionWS)
{
#ifdef _SPECULARHIGHLIGHTS_OFF
bool specularHighlightsOff = true;
#else
bool specularHighlightsOff = false;
#endif
const BRDFData noClearCoat = (BRDFData)0;
return LightingPhysicallyBased(brdfData, noClearCoat, light, normalWS, viewDirectionWS, 0.0, specularHighlightsOff);
}
half3 LightingPhysicallyBased(BRDFData brdfData, half3 lightColor, half3 lightDirectionWS, half lightAttenuation, half3 normalWS, half3 viewDirectionWS)
{
Light light;
light.color = lightColor;
light.direction = lightDirectionWS;
light.distanceAttenuation = lightAttenuation;
light.shadowAttenuation = 1;
return LightingPhysicallyBased(brdfData, light, normalWS, viewDirectionWS);
}
half3 LightingPhysicallyBased(BRDFData brdfData, Light light, half3 normalWS, half3 viewDirectionWS, bool specularHighlightsOff)
{
const BRDFData noClearCoat = (BRDFData)0;
return LightingPhysicallyBased(brdfData, noClearCoat, light, normalWS, viewDirectionWS, 0.0, specularHighlightsOff);
}
half3 LightingPhysicallyBased(BRDFData brdfData, half3 lightColor, half3 lightDirectionWS, half lightAttenuation, half3 normalWS, half3 viewDirectionWS, bool specularHighlightsOff)
{
Light light;
light.color = lightColor;
light.direction = lightDirectionWS;
light.distanceAttenuation = lightAttenuation;
light.shadowAttenuation = 1;
return LightingPhysicallyBased(brdfData, light, viewDirectionWS, specularHighlightsOff, specularHighlightsOff);
}
half3 VertexLighting(float3 positionWS, half3 normalWS)
{
half3 vertexLightColor = half3(0.0, 0.0, 0.0);
#ifdef _ADDITIONAL_LIGHTS_VERTEX
uint lightsCount = GetAdditionalLightsCount();
for (uint lightIndex = 0u; lightIndex < lightsCount; ++lightIndex)
{
Light light = GetAdditionalLight(lightIndex, positionWS);
half3 lightColor = light.color * light.distanceAttenuation;
vertexLightColor += LightingLambert(lightColor, light.direction, normalWS);
}
#endif
return vertexLightColor;
}
///////////////////////////////////////////////////////////////////////////////
// Fragment Functions //
// Used by ShaderGraph and others builtin renderers //
///////////////////////////////////////////////////////////////////////////////
half4 UniversalFragmentPBR(InputData inputData, SurfaceData surfaceData)
{
#ifdef _SPECULARHIGHLIGHTS_OFF
bool specularHighlightsOff = true;
#else
bool specularHighlightsOff = false;
#endif
BRDFData brdfData;
// NOTE: can modify alpha
InitializeBRDFData(surfaceData.albedo, surfaceData.metallic, surfaceData.specular, surfaceData.smoothness, surfaceData.alpha, brdfData);
BRDFData brdfDataClearCoat = (BRDFData)0;
#if defined(_CLEARCOAT) || defined(_CLEARCOATMAP)
// base brdfData is modified here, rely on the compiler to eliminate dead computation by InitializeBRDFData()
InitializeBRDFDataClearCoat(surfaceData.clearCoatMask, surfaceData.clearCoatSmoothness, brdfData, brdfDataClearCoat);
#endif
// To ensure backward compatibility we have to avoid using shadowMask input, as it is not present in older shaders
#if defined(SHADOWS_SHADOWMASK) && defined(LIGHTMAP_ON)
half4 shadowMask = inputData.shadowMask;
#elif !defined (LIGHTMAP_ON)
half4 shadowMask = unity_ProbesOcclusion;
#else
half4 shadowMask = half4(1, 1, 1, 1);
#endif
Light mainLight = GetMainLight(inputData.shadowCoord, inputData.positionWS, shadowMask);
#if defined(_SCREEN_SPACE_OCCLUSION)
AmbientOcclusionFactor aoFactor = GetScreenSpaceAmbientOcclusion(inputData.normalizedScreenSpaceUV);
mainLight.color *= aoFactor.directAmbientOcclusion;
surfaceData.occlusion = min(surfaceData.occlusion, aoFactor.indirectAmbientOcclusion);
#endif
MixRealtimeAndBakedGI(mainLight, inputData.normalWS, inputData.bakedGI);
half3 color = GlobalIllumination(brdfData, brdfDataClearCoat, surfaceData.clearCoatMask,
inputData.bakedGI, surfaceData.occlusion,
inputData.normalWS, inputData.viewDirectionWS);
color += LightingPhysicallyBased(brdfData, brdfDataClearCoat,
mainLight,
inputData.normalWS, inputData.viewDirectionWS,
surfaceData.clearCoatMask, specularHighlightsOff);
#ifdef _ADDITIONAL_LIGHTS
uint pixelLightCount = GetAdditionalLightsCount();
for (uint lightIndex = 0u; lightIndex < pixelLightCount; ++lightIndex)
{
Light light = GetAdditionalLight(lightIndex, inputData.positionWS, shadowMask);
#if defined(_SCREEN_SPACE_OCCLUSION)
light.color *= aoFactor.directAmbientOcclusion;
#endif
color += LightingPhysicallyBased(brdfData, brdfDataClearCoat,
light,
inputData.normalWS, inputData.viewDirectionWS,
surfaceData.clearCoatMask, specularHighlightsOff);
}
#endif
#ifdef _ADDITIONAL_LIGHTS_VERTEX
color += inputData.vertexLighting * brdfData.diffuse;
#endif
color += surfaceData.emission;
return half4(color, surfaceData.alpha);
}
half4 UniversalFragmentPBR(InputData inputData, half3 albedo, half metallic, half3 specular,
half smoothness, half occlusion, half3 emission, half alpha)
{
SurfaceData s;
s.albedo = albedo;
s.metallic = metallic;
s.specular = specular;
s.smoothness = smoothness;
s.occlusion = occlusion;
s.emission = emission;
s.alpha = alpha;
s.clearCoatMask = 0.0;
s.clearCoatSmoothness = 1.0;
return UniversalFragmentPBR(inputData, s);
}
half4 UniversalFragmentBlinnPhong(InputData inputData, half3 diffuse, half4 specularGloss, half smoothness, half3 emission, half alpha)
{
// To ensure backward compatibility we have to avoid using shadowMask input, as it is not present in older shaders
#if defined(SHADOWS_SHADOWMASK) && defined(LIGHTMAP_ON)
half4 shadowMask = inputData.shadowMask;
#elif !defined (LIGHTMAP_ON)
half4 shadowMask = unity_ProbesOcclusion;
#else
half4 shadowMask = half4(1, 1, 1, 1);
#endif
Light mainLight = GetMainLight(inputData.shadowCoord, inputData.positionWS, shadowMask);
#if defined(_SCREEN_SPACE_OCCLUSION)
AmbientOcclusionFactor aoFactor = GetScreenSpaceAmbientOcclusion(inputData.normalizedScreenSpaceUV);
mainLight.color *= aoFactor.directAmbientOcclusion;
inputData.bakedGI *= aoFactor.indirectAmbientOcclusion;
#endif
MixRealtimeAndBakedGI(mainLight, inputData.normalWS, inputData.bakedGI);
half3 attenuatedLightColor = mainLight.color * (mainLight.distanceAttenuation * mainLight.shadowAttenuation);
half3 diffuseColor = inputData.bakedGI + LightingLambert(attenuatedLightColor, mainLight.direction, inputData.normalWS);
half3 specularColor = LightingSpecular(attenuatedLightColor, mainLight.direction, inputData.normalWS, inputData.viewDirectionWS, specularGloss, smoothness);
#ifdef _ADDITIONAL_LIGHTS
uint pixelLightCount = GetAdditionalLightsCount();
for (uint lightIndex = 0u; lightIndex < pixelLightCount; ++lightIndex)
{
Light light = GetAdditionalLight(lightIndex, inputData.positionWS, shadowMask);
#if defined(_SCREEN_SPACE_OCCLUSION)
light.color *= aoFactor.directAmbientOcclusion;
#endif
half3 attenuatedLightColor = light.color * (light.distanceAttenuation * light.shadowAttenuation);
diffuseColor += LightingLambert(attenuatedLightColor, light.direction, inputData.normalWS);
specularColor += LightingSpecular(attenuatedLightColor, light.direction, inputData.normalWS, inputData.viewDirectionWS, specularGloss, smoothness);
}
#endif
#ifdef _ADDITIONAL_LIGHTS_VERTEX
diffuseColor += inputData.vertexLighting;
#endif
half3 finalColor = diffuseColor * diffuse + emission;
#if defined(_SPECGLOSSMAP) || defined(_SPECULAR_COLOR)
finalColor += specularColor;
#endif
return half4(finalColor, alpha);
}
//LWRP -> Universal Backwards Compatibility
half4 LightweightFragmentPBR(InputData inputData, half3 albedo, half metallic, half3 specular,
half smoothness, half occlusion, half3 emission, half alpha)
{
return UniversalFragmentPBR(inputData, albedo, metallic, specular, smoothness, occlusion, emission, alpha);
}
half4 LightweightFragmentBlinnPhong(InputData inputData, half3 diffuse, half4 specularGloss, half smoothness, half3 emission, half alpha)
{
return UniversalFragmentBlinnPhong(inputData, diffuse, specularGloss, smoothness, emission, alpha);
}
#endif
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