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Diffstat (limited to 'indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl')
| -rw-r--r-- | indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl b/indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl new file mode 100644 index 0000000000..e60ddcd569 --- /dev/null +++ b/indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl @@ -0,0 +1,172 @@ +/** + * @file radianceGenF.glsl + * + * $LicenseInfo:firstyear=2022&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2022, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + + +/*[EXTRA_CODE_HERE]*/ + +out vec4 frag_color; + +uniform samplerCubeArray reflectionProbes; +uniform int sourceIdx; + +VARYING vec3 vary_dir; + +//uniform float roughness; + +uniform float mipLevel; +uniform int u_width; +uniform float max_probe_lod; + + +// ============================================================================================================= +// Parts of this file are (c) 2018 Sascha Willems +// SNIPPED FROM https://github.com/SaschaWillems/Vulkan-glTF-PBR/blob/master/data/shaders/prefilterenvmap.frag +/* +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. +*/ +// ============================================================================================================= + +const float PI = 3.1415926536; + +// 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 * 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); +} + +// Normal Distribution function +float D_GGX(float dotNH, float roughness) +{ + float alpha = roughness * roughness; + float alpha2 = alpha * alpha; + float denom = dotNH * dotNH * (alpha2 - 1.0) + 1.0; + return (alpha2)/(PI * denom*denom); +} + +vec4 prefilterEnvMap(vec3 R) +{ + vec3 N = R; + vec3 V = R; + vec4 color = vec4(0.0); + float totalWeight = 0.0; + float envMapDim = u_width; + int numSamples = 4; + + float numMips = max_probe_lod; + + float roughness = mipLevel/numMips; + + numSamples = max(int(numSamples*roughness), 1); + + for(uint i = 0u; i < numSamples; i++) { + vec2 Xi = hammersley2d(i, numSamples); + vec3 H = importanceSample_GGX(Xi, roughness, N); + vec3 L = 2.0 * dot(V, H) * H - V; + float dotNL = clamp(dot(N, L), 0.0, 1.0); + if(dotNL > 0.0) { + // Filtering based on https://placeholderart.wordpress.com/2015/07/28/implementation-notes-runtime-environment-map-filtering-for-image-based-lighting/ + + float dotNH = clamp(dot(N, H), 0.0, 1.0); + float dotVH = clamp(dot(V, H), 0.0, 1.0); + + // Probability Distribution Function + float pdf = D_GGX(dotNH, roughness) * dotNH / (4.0 * dotVH) + 0.0001; + // Slid angle of current smple + float omegaS = 1.0 / (float(numSamples) * pdf); + // Solid angle of 1 pixel across all cube faces + float omegaP = 4.0 * PI / (6.0 * envMapDim * envMapDim); + // Biased (+1.0) mip level for better result + float mip = roughness == 0.0 ? 0.0 : clamp(0.5 * log2(omegaS / omegaP) + 1.0, 0.0f, numMips); + //float mip = clamp(0.5 * log2(omegaS / omegaP) + 1.0, 0.0f, 7.f); + color += textureLod(reflectionProbes, vec4(L,sourceIdx), mip) * dotNL; + totalWeight += dotNL; + + } + } + return (color / totalWeight); +} + +void main() +{ + vec3 N = normalize(vary_dir); + frag_color = prefilterEnvMap(N); +} +// ============================================================================================================= |