forked from bartvdbraak/blender
Brecht Van Lommel
7613ffc944
This was already done for the Principled BSDF to be compatible with typical baked roughness maps in PBR workflows.
61 lines
1.8 KiB
Plaintext
61 lines
1.8 KiB
Plaintext
/*
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* Copyright 2011-2013 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "stdosl.h"
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shader node_anisotropic_bsdf(
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color Color = 0.0,
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string distribution = "GGX",
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float Roughness = 0.0,
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float Anisotropy = 0.0,
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float Rotation = 0.0,
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normal Normal = N,
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normal Tangent = normalize(dPdu),
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output closure color BSDF = 0)
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{
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/* rotate tangent around normal */
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vector T = Tangent;
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if (Rotation != 0.0)
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T = rotate(T, Rotation * M_2PI, point(0.0, 0.0, 0.0), Normal);
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/* compute roughness */
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float roughness = Roughness * Roughness;
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float roughness_u, roughness_v;
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float aniso = clamp(Anisotropy, -0.99, 0.99);
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if (aniso < 0.0) {
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roughness_u = roughness / (1.0 + aniso);
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roughness_v = roughness * (1.0 + aniso);
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}
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else {
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roughness_u = roughness * (1.0 - aniso);
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roughness_v = roughness / (1.0 - aniso);
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}
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if (distribution == "sharp")
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BSDF = Color * reflection(Normal);
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else if (distribution == "beckmann")
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BSDF = Color * microfacet_beckmann_aniso(Normal, T, roughness_u, roughness_v);
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else if (distribution == "GGX")
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BSDF = Color * microfacet_ggx_aniso(Normal, T, roughness_u, roughness_v);
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else if (distribution == "Multiscatter GGX")
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BSDF = Color * microfacet_multi_ggx_aniso(Normal, T, roughness_u, roughness_v, Color);
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else
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BSDF = Color * ashikhmin_shirley(Normal, T, roughness_u, roughness_v);
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}
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