diff options
Diffstat (limited to 'source/blender/draw/engines/eevee/shaders/probe_filter_frag.glsl')
-rw-r--r-- | source/blender/draw/engines/eevee/shaders/probe_filter_frag.glsl | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/source/blender/draw/engines/eevee/shaders/probe_filter_frag.glsl b/source/blender/draw/engines/eevee/shaders/probe_filter_frag.glsl new file mode 100644 index 00000000000..bee674e3e76 --- /dev/null +++ b/source/blender/draw/engines/eevee/shaders/probe_filter_frag.glsl @@ -0,0 +1,49 @@ + +uniform samplerCube probeHdr; +uniform float roughnessSquared; +uniform float lodFactor; +uniform float lodMax; + +in vec3 worldPosition; + +out vec4 FragColor; + +void main() { + vec3 N, T, B, V; + + vec3 R = normalize(worldPosition); + + /* Isotropic assumption */ + N = V = R; + + make_orthonormal_basis(N, T, B); /* Generate tangent space */ + + /* Noise to dither the samples */ + /* Note : ghosting is better looking than noise. */ + // setup_noise(); + + /* Integrating Envmap */ + float weight = 0.0; + vec3 out_radiance = vec3(0.0); + for (float i = 0; i < sampleCount; i++) { + vec3 H = sample_ggx(i, roughnessSquared, N, T, B); /* Microfacet normal */ + vec3 L = -reflect(V, H); + float NL = dot(N, L); + + if (NL > 0.0) { + float NH = max(1e-8, dot(N, H)); /* cosTheta */ + + /* Coarse Approximation of the mapping distortion + * Unit Sphere -> Cubemap Face */ + const float dist = 4.0 * M_PI / 6.0; + float pdf = pdf_ggx_reflect(NH, roughnessSquared); + /* http://http.developer.nvidia.com/GPUGems3/gpugems3_ch20.html : Equation 13 */ + float lod = clamp(lodFactor - 0.5 * log2(pdf * dist), 0.0, lodMax) ; + + out_radiance += textureLod(probeHdr, L, lod).rgb * NL; + weight += NL; + } + } + + FragColor = vec4(out_radiance / weight, 1.0); +}
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