77 lines
3.2 KiB
GLSL
77 lines
3.2 KiB
GLSL
#line 10001
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#ifdef COMPILEPS
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float GetMipFromRoughness(float roughness)
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{
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return (roughness * 12.0 - pow(roughness, 6.0) * 1.5);
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}
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vec3 EnvBRDFApprox (vec3 SpecularColor, float Roughness, float NoV)
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{
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vec4 c0 = vec4(-1, -0.0275, -0.572, 0.022 );
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vec4 c1 = vec4(1, 0.0425, 1.0, -0.04 );
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vec4 r = Roughness * c0 + c1;
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float a004 = min( r.x * r.x, exp2( -9.28 * NoV ) ) * r.x + r.y;
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vec2 AB = vec2( -1.04, 1.04 ) * a004 + r.zw;
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return SpecularColor * AB.x + AB.y;
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}
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vec3 FixCubeLookup(vec3 v)
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{
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float M = max(max(abs(v.x), abs(v.y)), abs(v.z));
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float scale = (1024 - 1) / 1024;
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if (abs(v.x) != M) v.x += scale;
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if (abs(v.y) != M) v.y += scale;
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if (abs(v.z) != M) v.z += scale;
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return v;
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}
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/// Calculate IBL contributation
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/// reflectVec: reflection vector for cube sampling
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/// wsNormal: surface normal in word space
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/// toCamera: normalized direction from surface point to camera
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/// roughness: surface roughness
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/// ambientOcclusion: ambient occlusion
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vec3 ImageBasedLighting(vec3 reflectVec, vec3 wsNormal, vec3 toCamera, vec3 diffColor, vec3 specColor, float roughness, inout vec3 reflectionCubeColor)
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{
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roughness = max(roughness, 0.08);
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reflectVec = GetSpecularDominantDir(wsNormal, reflectVec, roughness);
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float ndv = clamp(dot(-toCamera, wsNormal), 0.0, 1.0);
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// PMREM Mipmapmode https://seblagarde.wordpress.com/2012/06/10/amd-cubemapgen-for-physically-based-rendering/
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//float GlossScale = 16.0;
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//float GlossBias = 5.0;
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float mipSelect = GetMipFromRoughness(roughness); //exp2(GlossScale * roughness * roughness + GlossBias) - exp2(GlossBias);
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// OpenGL ES does not support textureLod without extensions and does not have the sZoneCubeMap sampler,
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// so for now, sample without explicit LOD, and from the environment sampler, where the zone texture will be put
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// on mobile hardware
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#ifndef GL_ES
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vec3 cube = textureLod(sZoneCubeMap, FixCubeLookup(reflectVec), mipSelect).rgb;
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vec3 cubeD = textureLod(sZoneCubeMap, FixCubeLookup(wsNormal), 9.0).rgb;
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#else
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vec3 cube = textureCube(sEnvCubeMap, FixCubeLookup(reflectVec)).rgb;
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vec3 cubeD = textureCube(sEnvCubeMap, FixCubeLookup(wsNormal)).rgb;
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#endif
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// Fake the HDR texture
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float brightness = clamp(cAmbientColor.a, 0.0, 1.0);
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float darknessCutoff = clamp((cAmbientColor.a - 1.0) * 0.1, 0.0, 0.25);
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const float hdrMaxBrightness = 5.0;
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vec3 hdrCube = pow(cube + darknessCutoff, vec3(max(1.0, cAmbientColor.a)));
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hdrCube += max(vec3(0.0), hdrCube - vec3(1.0)) * hdrMaxBrightness;
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vec3 hdrCubeD = pow(cubeD + darknessCutoff, vec3(max(1.0, cAmbientColor.a)));
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hdrCubeD += max(vec3(0.0), hdrCubeD - vec3(1.0)) * hdrMaxBrightness;
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vec3 environmentSpecular = EnvBRDFApprox(specColor, roughness, ndv);
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vec3 environmentDiffuse = EnvBRDFApprox(diffColor, 1.0, ndv);
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return (hdrCube * environmentSpecular + hdrCubeD * environmentDiffuse) * brightness;
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}
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#endif
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