blender/intern/cycles/kernel/shaders/node_anisotropic_bsdf.osl
Karsten Schwenk 8ce1090d4e Cycles: Ashikhmin-Shirley anisotropic BSDF
* Ashikhmin-Shirley anisotropic BSDF was added as closure
* Anisotropic BSDF node now has two distributions

Reviewers: brecht, dingto

Differential Revision: https://developer.blender.org/D549
2014-06-14 13:49:57 +02:00

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/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License
*/
#include "stdosl.h"
shader node_anisotropic_bsdf(
color Color = 0.0,
string distribution = "Ward",
float Roughness = 0.0,
float Anisotropy = 0.0,
float Rotation = 0.0,
normal Normal = N,
normal Tangent = normalize(dPdu),
output closure color BSDF = 0)
{
/* rotate tangent around normal */
vector T = Tangent;
if (Rotation != 0.0)
T = rotate(T, Rotation * M_2PI, point(0.0, 0.0, 0.0), Normal);
/* compute roughness */
float RoughnessU, RoughnessV;
float aniso = clamp(Anisotropy, -0.99, 0.99);
if (aniso < 0.0) {
RoughnessU = Roughness / (1.0 + aniso);
RoughnessV = Roughness * (1.0 + aniso);
}
else {
RoughnessU = Roughness * (1.0 - aniso);
RoughnessV = Roughness / (1.0 - aniso);
}
if (distribution == "Ashikhmin-Shirley")
BSDF = Color * ashikhmin_shirley(Normal, T, RoughnessU, RoughnessV);
else
BSDF = Color * ward(Normal, T, RoughnessU, RoughnessV);
}