71dfcf4558
Replaces all usage by the the gpu_shader_math equivalent. This is because the old shader library was quite tangled. This avoids dependency hell trying to mix libraries. Changes are split into isolated commits until I had to do mass changes because of inter- dependencies. Pull Request: https://projects.blender.org/blender/blender/pulls/113631
41 lines
1.0 KiB
GLSL
41 lines
1.0 KiB
GLSL
/* SPDX-FileCopyrightText: 2019-2022 Blender Authors
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*
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* SPDX-License-Identifier: GPL-2.0-or-later */
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float fresnel_dielectric_cos(float cosi, float eta)
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{
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/* compute fresnel reflectance without explicitly computing
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* the refracted direction */
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float c = abs(cosi);
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float g = eta * eta - 1.0 + c * c;
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float result;
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if (g > 0.0) {
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g = sqrt(g);
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float A = (g - c) / (g + c);
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float B = (c * (g + c) - 1.0) / (c * (g - c) + 1.0);
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result = 0.5 * A * A * (1.0 + B * B);
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}
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else {
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result = 1.0; /* TIR (no refracted component) */
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}
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return result;
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}
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float fresnel_dielectric(vec3 Incoming, vec3 Normal, float eta)
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{
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/* compute fresnel reflectance without explicitly computing
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* the refracted direction */
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return fresnel_dielectric_cos(dot(Incoming, Normal), eta);
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}
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void node_fresnel(float ior, vec3 N, out float result)
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{
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N = normalize(N);
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vec3 V = coordinate_incoming(g_data.P);
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float eta = max(ior, 0.00001);
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result = fresnel_dielectric(V, N, (FrontFacing) ? eta : 1.0 / eta);
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}
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