Singularity/Library/PackageCache/com.unity.render-pipelines..../ShaderLibrary/EntityLighting.hlsl

379 lines
16 KiB
HLSL
Raw Permalink Normal View History

2024-05-06 14:45:45 -04:00
#ifndef UNITY_ENTITY_LIGHTING_INCLUDED
#define UNITY_ENTITY_LIGHTING_INCLUDED
#if SHADER_API_MOBILE || SHADER_API_GLES || SHADER_API_GLES3
#pragma warning (disable : 3205) // conversion of larger type to smaller
#endif
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Color.hlsl"
#define LIGHTMAP_RGBM_MAX_GAMMA real(5.0) // NB: Must match value in RGBMRanges.h
#define LIGHTMAP_RGBM_MAX_LINEAR real(34.493242) // LIGHTMAP_RGBM_MAX_GAMMA ^ 2.2
#ifdef UNITY_LIGHTMAP_RGBM_ENCODING
#ifdef UNITY_COLORSPACE_GAMMA
#define LIGHTMAP_HDR_MULTIPLIER LIGHTMAP_RGBM_MAX_GAMMA
#define LIGHTMAP_HDR_EXPONENT real(1.0) // Not used in gamma color space
#else
#define LIGHTMAP_HDR_MULTIPLIER LIGHTMAP_RGBM_MAX_LINEAR
#define LIGHTMAP_HDR_EXPONENT real(2.2)
#endif
#elif defined(UNITY_LIGHTMAP_DLDR_ENCODING)
#ifdef UNITY_COLORSPACE_GAMMA
#define LIGHTMAP_HDR_MULTIPLIER real(2.0)
#else
#define LIGHTMAP_HDR_MULTIPLIER real(4.59) // 2.0 ^ 2.2
#endif
#define LIGHTMAP_HDR_EXPONENT real(0.0)
#else // (UNITY_LIGHTMAP_FULL_HDR)
#define LIGHTMAP_HDR_MULTIPLIER real(1.0)
#define LIGHTMAP_HDR_EXPONENT real(1.0)
#endif
// TODO: Check if PI is correctly handled!
// Ref: "Efficient Evaluation of Irradiance Environment Maps" from ShaderX 2
real3 SHEvalLinearL0L1(real3 N, real4 shAr, real4 shAg, real4 shAb)
{
real4 vA = real4(N, 1.0);
real3 x1;
// Linear (L1) + constant (L0) polynomial terms
x1.r = dot(shAr, vA);
x1.g = dot(shAg, vA);
x1.b = dot(shAb, vA);
return x1;
}
real3 SHEvalLinearL1(real3 N, real3 shAr, real3 shAg, real3 shAb)
{
real3 x1;
x1.r = dot(shAr, N);
x1.g = dot(shAg, N);
x1.b = dot(shAb, N);
return x1;
}
real3 SHEvalLinearL2(real3 N, real4 shBr, real4 shBg, real4 shBb, real4 shC)
{
real3 x2;
// 4 of the quadratic (L2) polynomials
real4 vB = N.xyzz * N.yzzx;
x2.r = dot(shBr, vB);
x2.g = dot(shBg, vB);
x2.b = dot(shBb, vB);
// Final (5th) quadratic (L2) polynomial
real vC = N.x * N.x - N.y * N.y;
real3 x3 = shC.rgb * vC;
return x2 + x3;
}
#if HAS_HALF
half3 SampleSH9(half4 SHCoefficients[7], half3 N)
{
half4 shAr = SHCoefficients[0];
half4 shAg = SHCoefficients[1];
half4 shAb = SHCoefficients[2];
half4 shBr = SHCoefficients[3];
half4 shBg = SHCoefficients[4];
half4 shBb = SHCoefficients[5];
half4 shCr = SHCoefficients[6];
// Linear + constant polynomial terms
half3 res = SHEvalLinearL0L1(N, shAr, shAg, shAb);
// Quadratic polynomials
res += SHEvalLinearL2(N, shBr, shBg, shBb, shCr);
#ifdef UNITY_COLORSPACE_GAMMA
res = LinearToSRGB(res);
#endif
return res;
}
#endif
float3 SampleSH9(float4 SHCoefficients[7], float3 N)
{
float4 shAr = SHCoefficients[0];
float4 shAg = SHCoefficients[1];
float4 shAb = SHCoefficients[2];
float4 shBr = SHCoefficients[3];
float4 shBg = SHCoefficients[4];
float4 shBb = SHCoefficients[5];
float4 shCr = SHCoefficients[6];
// Linear + constant polynomial terms
float3 res = SHEvalLinearL0L1(N, shAr, shAg, shAb);
// Quadratic polynomials
res += SHEvalLinearL2(N, shBr, shBg, shBb, shCr);
#ifdef UNITY_COLORSPACE_GAMMA
res = LinearToSRGB(res);
#endif
return res;
}
// texture3dLod is not supported on gles2.
#if !defined(SHADER_API_GLES)
// This sample a 3D volume storing SH
// Volume is store as 3D texture with 4 R, G, B, Occ set of 4 coefficient store atlas in same 3D texture. Occ is use for occlusion.
// TODO: the packing here is inefficient as we will fetch values far away from each other and they may not fit into the cache - Suggest we pack RGB continuously
// TODO: The calcul of texcoord could be perform with a single matrix multicplication calcualted on C++ side that will fold probeVolumeMin and probeVolumeSizeInv into it and handle the identity case, no reasons to do it in C++ (ask Ionut about it)
// It should also handle the camera relative path (if the render pipeline use it)
// bakeDiffuseLighting and backBakeDiffuseLighting must be initialize outside the function
void SampleProbeVolumeSH4(TEXTURE3D_PARAM(SHVolumeTexture, SHVolumeSampler), float3 positionWS, float3 normalWS, float3 backNormalWS, float4x4 WorldToTexture,
float transformToLocal, float texelSizeX, float3 probeVolumeMin, float3 probeVolumeSizeInv,
inout float3 bakeDiffuseLighting, inout float3 backBakeDiffuseLighting)
{
float3 position = (transformToLocal == 1.0) ? mul(WorldToTexture, float4(positionWS, 1.0)).xyz : positionWS;
float3 texCoord = (position - probeVolumeMin) * probeVolumeSizeInv.xyz;
// Each component is store in the same texture 3D. Each use one quater on the x axis
// Here we get R component then increase by step size (0.25) to get other component. This assume 4 component
// but last one is not used.
// Clamp to edge of the "internal" texture, as R is from half texel to size of R texture minus half texel.
// This avoid leaking
texCoord.x = clamp(texCoord.x * 0.25, 0.5 * texelSizeX, 0.25 - 0.5 * texelSizeX);
float4 shAr = SAMPLE_TEXTURE3D_LOD(SHVolumeTexture, SHVolumeSampler, texCoord, 0);
texCoord.x += 0.25;
float4 shAg = SAMPLE_TEXTURE3D_LOD(SHVolumeTexture, SHVolumeSampler, texCoord, 0);
texCoord.x += 0.25;
float4 shAb = SAMPLE_TEXTURE3D_LOD(SHVolumeTexture, SHVolumeSampler, texCoord, 0);
bakeDiffuseLighting += SHEvalLinearL0L1(normalWS, shAr, shAg, shAb);
backBakeDiffuseLighting += SHEvalLinearL0L1(backNormalWS, shAr, shAg, shAb);
}
// Just a shortcut that call function above
float3 SampleProbeVolumeSH4(TEXTURE3D_PARAM(SHVolumeTexture, SHVolumeSampler), float3 positionWS, float3 normalWS, float4x4 WorldToTexture,
float transformToLocal, float texelSizeX, float3 probeVolumeMin, float3 probeVolumeSizeInv)
{
float3 backNormalWSUnused = 0.0;
float3 bakeDiffuseLighting = 0.0;
float3 backBakeDiffuseLightingUnused = 0.0;
SampleProbeVolumeSH4(TEXTURE3D_ARGS(SHVolumeTexture, SHVolumeSampler), positionWS, normalWS, backNormalWSUnused, WorldToTexture,
transformToLocal, texelSizeX, probeVolumeMin, probeVolumeSizeInv,
bakeDiffuseLighting, backBakeDiffuseLightingUnused);
return bakeDiffuseLighting;
}
// The SphericalHarmonicsL2 coefficients are packed into 7 coefficients per color channel instead of 9.
// The packing from 9 to 7 is done from engine code and will use the alpha component of the pixel to store an additional SH coefficient.
// The 3D atlas texture will contain 7 SH coefficient parts.
// bakeDiffuseLighting and backBakeDiffuseLighting must be initialize outside the function
void SampleProbeVolumeSH9(TEXTURE3D_PARAM(SHVolumeTexture, SHVolumeSampler), float3 positionWS, float3 normalWS, float3 backNormalWS, float4x4 WorldToTexture,
float transformToLocal, float texelSizeX, float3 probeVolumeMin, float3 probeVolumeSizeInv,
inout float3 bakeDiffuseLighting, inout float3 backBakeDiffuseLighting)
{
float3 position = (transformToLocal == 1.0f) ? mul(WorldToTexture, float4(positionWS, 1.0)).xyz : positionWS;
float3 texCoord = (position - probeVolumeMin) * probeVolumeSizeInv;
const uint shCoeffCount = 7;
const float invShCoeffCount = 1.0f / float(shCoeffCount);
// We need to compute proper X coordinate to sample into the atlas.
texCoord.x = texCoord.x / shCoeffCount;
// Clamp the x coordinate otherwise we'll have leaking between RGB coefficients.
float texCoordX = clamp(texCoord.x, 0.5f * texelSizeX, invShCoeffCount - 0.5f * texelSizeX);
float4 SHCoefficients[7];
for (uint i = 0; i < shCoeffCount; i++)
{
texCoord.x = texCoordX + i * invShCoeffCount;
SHCoefficients[i] = SAMPLE_TEXTURE3D_LOD(SHVolumeTexture, SHVolumeSampler, texCoord, 0);
}
bakeDiffuseLighting += SampleSH9(SHCoefficients, normalize(normalWS));
backBakeDiffuseLighting += SampleSH9(SHCoefficients, normalize(backNormalWS));
}
// Just a shortcut that call function above
float3 SampleProbeVolumeSH9(TEXTURE3D_PARAM(SHVolumeTexture, SHVolumeSampler), float3 positionWS, float3 normalWS, float4x4 WorldToTexture,
float transformToLocal, float texelSizeX, float3 probeVolumeMin, float3 probeVolumeSizeInv)
{
float3 backNormalWSUnused = 0.0;
float3 bakeDiffuseLighting = 0.0;
float3 backBakeDiffuseLightingUnused = 0.0;
SampleProbeVolumeSH9(TEXTURE3D_ARGS(SHVolumeTexture, SHVolumeSampler), positionWS, normalWS, backNormalWSUnused, WorldToTexture,
transformToLocal, texelSizeX, probeVolumeMin, probeVolumeSizeInv,
bakeDiffuseLighting, backBakeDiffuseLightingUnused);
return bakeDiffuseLighting;
}
#endif
float4 SampleProbeOcclusion(TEXTURE3D_PARAM(SHVolumeTexture, SHVolumeSampler), float3 positionWS, float4x4 WorldToTexture,
float transformToLocal, float texelSizeX, float3 probeVolumeMin, float3 probeVolumeSizeInv)
{
float3 position = (transformToLocal == 1.0) ? mul(WorldToTexture, float4(positionWS, 1.0)).xyz : positionWS;
float3 texCoord = (position - probeVolumeMin) * probeVolumeSizeInv.xyz;
// Sample fourth texture in the atlas
// We need to compute proper U coordinate to sample.
// Clamp the coordinate otherwize we'll have leaking between ShB coefficients and Probe Occlusion(Occ) info
texCoord.x = max(texCoord.x * 0.25 + 0.75, 0.75 + 0.5 * texelSizeX);
return SAMPLE_TEXTURE3D(SHVolumeTexture, SHVolumeSampler, texCoord);
}
// Following functions are to sample enlighten lightmaps (or lightmaps encoded the same way as our
// enlighten implementation). They assume use of RGB9E5 for dynamic illuminance map and RGBM for baked ones.
// It is required for other platform that aren't supporting this format to implement variant of these functions
// (But these kind of platform should use regular render loop and not news shaders).
// TODO: This is the max value allowed for emissive (bad name - but keep for now to retrieve it) (It is 8^2.2 (gamma) and 8 is the limit of punctual light slider...), comme from UnityCg.cginc. Fix it!
// Ask Jesper if this can be change for HDRenderPipeline
#define EMISSIVE_RGBM_SCALE 97.0
// RGBM stuff is temporary. For now baked lightmap are in RGBM and the RGBM range for lightmaps is specific so we can't use the generic method.
// In the end baked lightmaps are going to be BC6H so the code will be the same as dynamic lightmaps.
// Same goes for emissive packed as an input for Enlighten with another hard coded multiplier.
// TODO: This function is used with the LightTransport pass to encode lightmap or emissive
real4 PackEmissiveRGBM(real3 rgb)
{
real kOneOverRGBMMaxRange = 1.0 / EMISSIVE_RGBM_SCALE;
const real kMinMultiplier = 2.0 * 1e-2;
real4 rgbm = real4(rgb * kOneOverRGBMMaxRange, 1.0);
rgbm.a = max(max(rgbm.r, rgbm.g), max(rgbm.b, kMinMultiplier));
rgbm.a = ceil(rgbm.a * 255.0) / 255.0;
// Division-by-zero warning from d3d9, so make compiler happy.
rgbm.a = max(rgbm.a, kMinMultiplier);
rgbm.rgb /= rgbm.a;
return rgbm;
}
real3 UnpackLightmapRGBM(real4 rgbmInput, real4 decodeInstructions)
{
#ifdef UNITY_COLORSPACE_GAMMA
return rgbmInput.rgb * (rgbmInput.a * decodeInstructions.x);
#else
return rgbmInput.rgb * (PositivePow(rgbmInput.a, decodeInstructions.y) * decodeInstructions.x);
#endif
}
real3 UnpackLightmapDoubleLDR(real4 encodedColor, real4 decodeInstructions)
{
return encodedColor.rgb * decodeInstructions.x;
}
#ifndef BUILTIN_TARGET_API
real3 DecodeLightmap(real4 encodedIlluminance, real4 decodeInstructions)
{
#if defined(UNITY_LIGHTMAP_RGBM_ENCODING)
return UnpackLightmapRGBM(encodedIlluminance, decodeInstructions);
#elif defined(UNITY_LIGHTMAP_DLDR_ENCODING)
return UnpackLightmapDoubleLDR(encodedIlluminance, decodeInstructions);
#else // (UNITY_LIGHTMAP_FULL_HDR)
return encodedIlluminance.rgb;
#endif
}
#endif
real3 DecodeHDREnvironment(real4 encodedIrradiance, real4 decodeInstructions)
{
// Take into account texture alpha if decodeInstructions.w is true(the alpha value affects the RGB channels)
real alpha = max(decodeInstructions.w * (encodedIrradiance.a - 1.0) + 1.0, 0.0);
// If Linear mode is not supported we can skip exponent part
return (decodeInstructions.x * PositivePow(alpha, decodeInstructions.y)) * encodedIrradiance.rgb;
}
#if defined(UNITY_DOTS_INSTANCING_ENABLED)
#define TEXTURE2D_LIGHTMAP_PARAM TEXTURE2D_ARRAY_PARAM
#define TEXTURE2D_LIGHTMAP_ARGS TEXTURE2D_ARRAY_ARGS
#define SAMPLE_TEXTURE2D_LIGHTMAP SAMPLE_TEXTURE2D_ARRAY
#define LIGHTMAP_EXTRA_ARGS float2 uv, float slice
#define LIGHTMAP_EXTRA_ARGS_USE uv, slice
#else
#define TEXTURE2D_LIGHTMAP_PARAM TEXTURE2D_PARAM
#define TEXTURE2D_LIGHTMAP_ARGS TEXTURE2D_ARGS
#define SAMPLE_TEXTURE2D_LIGHTMAP SAMPLE_TEXTURE2D
#define LIGHTMAP_EXTRA_ARGS float2 uv
#define LIGHTMAP_EXTRA_ARGS_USE uv
#endif
real3 SampleSingleLightmap(TEXTURE2D_LIGHTMAP_PARAM(lightmapTex, lightmapSampler), LIGHTMAP_EXTRA_ARGS, float4 transform, bool encodedLightmap, real4 decodeInstructions)
{
// transform is scale and bias
uv = uv * transform.xy + transform.zw;
real3 illuminance = real3(0.0, 0.0, 0.0);
// Remark: baked lightmap is RGBM for now, dynamic lightmap is RGB9E5
if (encodedLightmap)
{
real4 encodedIlluminance = SAMPLE_TEXTURE2D_LIGHTMAP(lightmapTex, lightmapSampler, LIGHTMAP_EXTRA_ARGS_USE).rgba;
illuminance = DecodeLightmap(encodedIlluminance, decodeInstructions);
}
else
{
illuminance = SAMPLE_TEXTURE2D_LIGHTMAP(lightmapTex, lightmapSampler, LIGHTMAP_EXTRA_ARGS_USE).rgb;
}
return illuminance;
}
void SampleDirectionalLightmap(TEXTURE2D_LIGHTMAP_PARAM(lightmapTex, lightmapSampler), TEXTURE2D_LIGHTMAP_PARAM(lightmapDirTex, lightmapDirSampler), LIGHTMAP_EXTRA_ARGS, float4 transform,
float3 normalWS, float3 backNormalWS, bool encodedLightmap, real4 decodeInstructions, inout real3 bakeDiffuseLighting, inout real3 backBakeDiffuseLighting)
{
// In directional mode Enlighten bakes dominant light direction
// in a way, that using it for half Lambert and then dividing by a "rebalancing coefficient"
// gives a result close to plain diffuse response lightmaps, but normalmapped.
// Note that dir is not unit length on purpose. Its length is "directionality", like
// for the directional specular lightmaps.
// transform is scale and bias
uv = uv * transform.xy + transform.zw;
real4 direction = SAMPLE_TEXTURE2D_LIGHTMAP(lightmapDirTex, lightmapDirSampler, LIGHTMAP_EXTRA_ARGS_USE);
// Remark: baked lightmap is RGBM for now, dynamic lightmap is RGB9E5
real3 illuminance = real3(0.0, 0.0, 0.0);
if (encodedLightmap)
{
real4 encodedIlluminance = SAMPLE_TEXTURE2D_LIGHTMAP(lightmapTex, lightmapSampler, LIGHTMAP_EXTRA_ARGS_USE).rgba;
illuminance = DecodeLightmap(encodedIlluminance, decodeInstructions);
}
else
{
illuminance = SAMPLE_TEXTURE2D_LIGHTMAP(lightmapTex, lightmapSampler, LIGHTMAP_EXTRA_ARGS_USE).rgb;
}
real halfLambert = dot(normalWS, direction.xyz - 0.5) + 0.5;
bakeDiffuseLighting += illuminance * halfLambert / max(1e-4, direction.w);
real backHalfLambert = dot(backNormalWS, direction.xyz - 0.5) + 0.5;
backBakeDiffuseLighting += illuminance * backHalfLambert / max(1e-4, direction.w);
}
// Just a shortcut that call function above
real3 SampleDirectionalLightmap(TEXTURE2D_LIGHTMAP_PARAM(lightmapTex, lightmapSampler), TEXTURE2D_LIGHTMAP_PARAM(lightmapDirTex, lightmapDirSampler), LIGHTMAP_EXTRA_ARGS, float4 transform,
float3 normalWS, bool encodedLightmap, real4 decodeInstructions)
{
float3 backNormalWSUnused = 0.0;
real3 bakeDiffuseLighting = 0.0;
real3 backBakeDiffuseLightingUnused = 0.0;
SampleDirectionalLightmap(TEXTURE2D_LIGHTMAP_ARGS(lightmapTex, lightmapSampler), TEXTURE2D_LIGHTMAP_ARGS(lightmapDirTex, lightmapDirSampler), LIGHTMAP_EXTRA_ARGS_USE, transform,
normalWS, backNormalWSUnused, encodedLightmap, decodeInstructions, bakeDiffuseLighting, backBakeDiffuseLightingUnused);
return bakeDiffuseLighting;
}
#if SHADER_API_MOBILE || SHADER_API_GLES || SHADER_API_GLES3
#pragma warning (enable : 3205) // conversion of larger type to smaller
#endif
#endif // UNITY_ENTITY_LIGHTING_INCLUDED