forked from bartvdbraak/blender
da376e0237
Cycles uses code from some great open source projects, many thanks them: * BVH building and traversal code from NVidia's "Understanding the Efficiency of Ray Traversal on GPUs": http://code.google.com/p/understanding-the-efficiency-of-ray-traversal-on-gpus/ * Open Shading Language for a large part of the shading system: http://code.google.com/p/openshadinglanguage/ * Blender for procedural textures and a few other nodes. * Approximate Catmull Clark subdivision from NVidia Mesh tools: http://code.google.com/p/nvidia-mesh-tools/ * Sobol direction vectors from: http://web.maths.unsw.edu.au/~fkuo/sobol/ * Film response functions from: http://www.cs.columbia.edu/CAVE/software/softlib/dorf.php
41 lines
1.2 KiB
Plaintext
41 lines
1.2 KiB
Plaintext
/*
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* Copyright 2011, Blender Foundation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#include "stdosl.h"
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#include "node_fresnel.h"
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shader node_velvet_bsdf(
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color Color = color(0.8, 0.8, 0.8),
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float Sigma = 0.0,
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float Fresnel = 0.3,
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normal Normal = N,
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output closure color BSDF = diffuse(Normal))
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{
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float Fr = 1.0;
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if(Fresnel < 1.0) {
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float eta = 1.0/clamp(1.0 - Fresnel, 1e-5, 1.0 - 1e-5);
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Fr = fresnel_dielectric(I, Normal, eta);
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}
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float sigma = clamp(Sigma, 0.0, 1.0);
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BSDF = (Fr*Color)*ashikhmin_velvet(Normal, sigma);
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}
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