diff options
Diffstat (limited to 'indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl')
| -rw-r--r-- | indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl | 268 |
1 files changed, 243 insertions, 25 deletions
diff --git a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl index 652e609718..52345e7e51 100644 --- a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl +++ b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl @@ -23,9 +23,38 @@ * $/LicenseInfo$ */ + + + + +/* Parts of this file are taken from Sascha Willem's Vulkan GLTF refernce implementation +MIT License + +Copyright (c) 2018 Sascha Willems + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. +*/ + uniform sampler2DRect normalMap; uniform sampler2DRect depthMap; uniform sampler2D projectionMap; // rgba +uniform sampler2D brdfLut; // projected lighted params uniform mat4 proj_mat; //screen space to light space projector @@ -482,38 +511,227 @@ vec3 BRDFSpecularGGX( vec3 reflect0, vec3 reflect90, float alphaRough, float spe return fresnel * vis * d; } +// Based omn http://byteblacksmith.com/improvements-to-the-canonical-one-liner-glsl-rand-for-opengl-es-2-0/ +float random(vec2 co) +{ + float a = 12.9898; + float b = 78.233; + float c = 43758.5453; + float dt= dot(co.xy ,vec2(a,b)); + float sn= mod(dt,3.14); + return fract(sin(sn) * c); +} + +vec2 hammersley2d(uint i, uint N) +{ + // Radical inverse based on http://holger.dammertz.org/stuff/notes_HammersleyOnHemisphere.html + uint bits = (i << 16u) | (i >> 16u); + bits = ((bits & 0x55555555u) << 1u) | ((bits & 0xAAAAAAAAu) >> 1u); + bits = ((bits & 0x33333333u) << 2u) | ((bits & 0xCCCCCCCCu) >> 2u); + bits = ((bits & 0x0F0F0F0Fu) << 4u) | ((bits & 0xF0F0F0F0u) >> 4u); + bits = ((bits & 0x00FF00FFu) << 8u) | ((bits & 0xFF00FF00u) >> 8u); + float rdi = float(bits) * 2.3283064365386963e-10; + return vec2(float(i) /float(N), rdi); +} + +// Based on http://blog.selfshadow.com/publications/s2013-shading-course/karis/s2013_pbs_epic_slides.pdf +vec3 importanceSample_GGX(vec2 Xi, float roughness, vec3 normal) +{ + // Maps a 2D point to a hemisphere with spread based on roughness + float alpha = roughness * roughness; + float phi = 2.0 * M_PI * Xi.x + random(normal.xz) * 0.1; + float cosTheta = sqrt((1.0 - Xi.y) / (1.0 + (alpha*alpha - 1.0) * Xi.y)); + float sinTheta = sqrt(1.0 - cosTheta * cosTheta); + vec3 H = vec3(sinTheta * cos(phi), sinTheta * sin(phi), cosTheta); + + // Tangent space + vec3 up = abs(normal.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(1.0, 0.0, 0.0); + vec3 tangentX = normalize(cross(up, normal)); + vec3 tangentY = normalize(cross(normal, tangentX)); + + // Convert to world Space + return normalize(tangentX * H.x + tangentY * H.y + normal * H.z); +} + +// Geometric Shadowing function +float G_SchlicksmithGGX(float dotNL, float dotNV, float roughness) +{ + float k = (roughness * roughness) / 2.0; + float GL = dotNL / (dotNL * (1.0 - k) + k); + float GV = dotNV / (dotNV * (1.0 - k) + k); + return GL * GV; +} + +#define NUM_SAMPLES 16 + +vec2 BRDF(float NoV, float roughness) +{ +#if 0 + // Normal always points along z-axis for the 2D lookup + const vec3 N = vec3(0.0, 0.0, 1.0); + vec3 V = vec3(sqrt(1.0 - NoV*NoV), 0.0, NoV); + + vec2 LUT = vec2(0.0); + for(uint i = 0u; i < NUM_SAMPLES; i++) { + vec2 Xi = hammersley2d(i, NUM_SAMPLES); + vec3 H = importanceSample_GGX(Xi, roughness, N); + vec3 L = 2.0 * dot(V, H) * H - V; + + float dotNL = max(dot(N, L), 0.0); + float dotNV = max(dot(N, V), 0.0); + float dotVH = max(dot(V, H), 0.0); + float dotNH = max(dot(H, N), 0.0); + + if (dotNL > 0.0) { + float G = G_SchlicksmithGGX(dotNL, dotNV, roughness); + float G_Vis = (G * dotVH) / (dotNH * dotNV); + float Fc = pow(1.0 - dotVH, 5.0); + LUT += vec2((1.0 - Fc) * G_Vis, Fc * G_Vis); + } + } + return LUT / float(NUM_SAMPLES); +#else + return texture(brdfLut, vec2(NoV, roughness)).rg; +#endif +} + // set colorDiffuse and colorSpec to the results of GLTF PBR style IBL -void pbrIbl(out vec3 colorDiffuse, // diffuse color output - out vec3 colorSpec, // specular color output, +vec3 pbrIbl(vec3 diffuseColor, + vec3 specularColor, vec3 radiance, // radiance map sample vec3 irradiance, // irradiance map sample float ao, // ambient occlusion factor float nv, // normal dot view vector - float perceptualRough, // roughness factor - float gloss, // 1.0 - roughness factor - vec3 reflect0, // see also: initMaterial - vec3 c_diff) + float perceptualRough) { - // Common to RadianceGGX and RadianceLambertian - vec2 brdfPoint = clamp(vec2(nv, perceptualRough), vec2(0,0), vec2(1,1)); - vec2 vScaleBias = getGGX( brdfPoint); // Environment BRDF: scale and bias applied to reflect0 - vec3 fresnelR = max(vec3(gloss), reflect0) - reflect0; // roughness dependent fresnel - vec3 kSpec = reflect0 + fresnelR*pow(1.0 - nv, 5.0); - - vec3 FssEssGGX = kSpec*vScaleBias.x + vScaleBias.y; - colorSpec = radiance * FssEssGGX; + // retrieve a scale and bias to F0. See [1], Figure 3 + vec2 brdf = BRDF(clamp(nv, 0, 1), 1.0-perceptualRough); + vec3 diffuseLight = irradiance; + vec3 specularLight = radiance; - // Reference: getIBLRadianceLambertian fs - vec3 FssEssLambert = kSpec * vScaleBias.x + vScaleBias.y; // NOTE: Very similar to FssEssRadiance but with extra specWeight term - float Ems = 1.0 - (vScaleBias.x + vScaleBias.y); - vec3 avg = (reflect0 + (1.0 - reflect0) / 21.0); - vec3 AvgEms = avg * Ems; - vec3 FmsEms = AvgEms * FssEssLambert / (1.0 - AvgEms); - vec3 kDiffuse = c_diff * (1.0 - FssEssLambert + FmsEms); - colorDiffuse = (FmsEms + kDiffuse) * irradiance; + vec3 diffuse = diffuseLight * diffuseColor; + vec3 specular = specularLight * (specularColor * brdf.x + brdf.y); + + + return (diffuse + specular) * ao; +} + +// Encapsulate the various inputs used by the various functions in the shading equation +// We store values in this struct to simplify the integration of alternative implementations +// of the shading terms, outlined in the Readme.MD Appendix. +struct PBRInfo +{ + float NdotL; // cos angle between normal and light direction + float NdotV; // cos angle between normal and view direction + float NdotH; // cos angle between normal and half vector + float LdotH; // cos angle between light direction and half vector + float VdotH; // cos angle between view direction and half vector + float perceptualRoughness; // roughness value, as authored by the model creator (input to shader) + float metalness; // metallic value at the surface + vec3 reflectance0; // full reflectance color (normal incidence angle) + vec3 reflectance90; // reflectance color at grazing angle + float alphaRoughness; // roughness mapped to a more linear change in the roughness (proposed by [2]) + vec3 diffuseColor; // color contribution from diffuse lighting + vec3 specularColor; // color contribution from specular lighting +}; + +// Basic Lambertian diffuse +// Implementation from Lambert's Photometria https://archive.org/details/lambertsphotome00lambgoog +// See also [1], Equation 1 +vec3 diffuse(PBRInfo pbrInputs) +{ + return pbrInputs.diffuseColor / M_PI; +} + +// The following equation models the Fresnel reflectance term of the spec equation (aka F()) +// Implementation of fresnel from [4], Equation 15 +vec3 specularReflection(PBRInfo pbrInputs) +{ + return pbrInputs.reflectance0 + (pbrInputs.reflectance90 - pbrInputs.reflectance0) * pow(clamp(1.0 - pbrInputs.VdotH, 0.0, 1.0), 5.0); +} + +// This calculates the specular geometric attenuation (aka G()), +// where rougher material will reflect less light back to the viewer. +// This implementation is based on [1] Equation 4, and we adopt their modifications to +// alphaRoughness as input as originally proposed in [2]. +float geometricOcclusion(PBRInfo pbrInputs) +{ + float NdotL = pbrInputs.NdotL; + float NdotV = pbrInputs.NdotV; + float r = pbrInputs.alphaRoughness; + + float attenuationL = 2.0 * NdotL / (NdotL + sqrt(r * r + (1.0 - r * r) * (NdotL * NdotL))); + float attenuationV = 2.0 * NdotV / (NdotV + sqrt(r * r + (1.0 - r * r) * (NdotV * NdotV))); + return attenuationL * attenuationV; +} + +// The following equation(s) model the distribution of microfacet normals across the area being drawn (aka D()) +// Implementation from "Average Irregularity Representation of a Roughened Surface for Ray Reflection" by T. S. Trowbridge, and K. P. Reitz +// Follows the distribution function recommended in the SIGGRAPH 2013 course notes from EPIC Games [1], Equation 3. +float microfacetDistribution(PBRInfo pbrInputs) +{ + float roughnessSq = pbrInputs.alphaRoughness * pbrInputs.alphaRoughness; + float f = (pbrInputs.NdotH * roughnessSq - pbrInputs.NdotH) * pbrInputs.NdotH + 1.0; + return roughnessSq / (M_PI * f * f); +} + +vec3 pbrPunctual(vec3 diffuseColor, vec3 specularColor, + float perceptualRoughness, + float metallic, + vec3 n, // normal + vec3 v, // surface point to camera + vec3 l) //surface point to light +{ + float alphaRoughness = perceptualRoughness * perceptualRoughness; + + // Compute reflectance. + float reflectance = max(max(specularColor.r, specularColor.g), specularColor.b); + + // For typical incident reflectance range (between 4% to 100%) set the grazing reflectance to 100% for typical fresnel effect. + // For very low reflectance range on highly diffuse objects (below 4%), incrementally reduce grazing reflecance to 0%. + float reflectance90 = clamp(reflectance * 25.0, 0.0, 1.0); + vec3 specularEnvironmentR0 = specularColor.rgb; + vec3 specularEnvironmentR90 = vec3(1.0, 1.0, 1.0) * reflectance90; + + vec3 h = normalize(l+v); // Half vector between both l and v + vec3 reflection = -normalize(reflect(v, n)); + reflection.y *= -1.0f; + + float NdotL = clamp(dot(n, l), 0.001, 1.0); + float NdotV = clamp(abs(dot(n, v)), 0.001, 1.0); + float NdotH = clamp(dot(n, h), 0.0, 1.0); + float LdotH = clamp(dot(l, h), 0.0, 1.0); + float VdotH = clamp(dot(v, h), 0.0, 1.0); + + PBRInfo pbrInputs = PBRInfo( + NdotL, + NdotV, + NdotH, + LdotH, + VdotH, + perceptualRoughness, + metallic, + specularEnvironmentR0, + specularEnvironmentR90, + alphaRoughness, + diffuseColor, + specularColor + ); + + // Calculate the shading terms for the microfacet specular shading model + vec3 F = specularReflection(pbrInputs); + float G = geometricOcclusion(pbrInputs); + float D = microfacetDistribution(pbrInputs); + + const vec3 u_LightColor = vec3(1.0); + + // Calculation of analytical lighting contribution + vec3 diffuseContrib = (1.0 - F) * diffuse(pbrInputs); + vec3 specContrib = F * G * D / (4.0 * NdotL * NdotV); + // Obtain final intensity as reflectance (BRDF) scaled by the energy of the light (cosine law) + vec3 color = NdotL * u_LightColor * (diffuseContrib + specContrib); - colorDiffuse *= ao; - colorSpec *= ao; + return color; } void pbrDirectionalLight(inout vec3 colorDiffuse, @@ -529,7 +747,7 @@ void pbrDirectionalLight(inout vec3 colorDiffuse, float nv, float nh) { - float scale = 16.0; + float scale = 32.0; vec3 sunColor = sunlit * scale; // scol = sun shadow |