Blender V2.61 - r43446

bsdf_refraction.cpp

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00001 /*
00002  * Adapted from Open Shading Language with this license:
00003  *
00004  * Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
00005  * All Rights Reserved.
00006  *
00007  * Modifications Copyright 2011, Blender Foundation.
00008  * 
00009  * Redistribution and use in source and binary forms, with or without
00010  * modification, are permitted provided that the following conditions are
00011  * met:
00012  * * Redistributions of source code must retain the above copyright
00013  *   notice, this list of conditions and the following disclaimer.
00014  * * Redistributions in binary form must reproduce the above copyright
00015  *   notice, this list of conditions and the following disclaimer in the
00016  *   documentation and/or other materials provided with the distribution.
00017  * * Neither the name of Sony Pictures Imageworks nor the names of its
00018  *   contributors may be used to endorse or promote products derived from
00019  *   this software without specific prior written permission.
00020  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00021  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00022  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
00023  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
00024  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00025  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00026  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00027  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00028  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00029  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00030  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00031  */
00032 
00033 #include <OpenImageIO/fmath.h>
00034 
00035 #include <OSL/genclosure.h>
00036 
00037 #include "osl_closures.h"
00038 
00039 CCL_NAMESPACE_BEGIN
00040 
00041 using namespace OSL;
00042 
00043 class RefractionClosure : public BSDFClosure {
00044 public:
00045     Vec3  m_N;     // shading normal
00046     float m_eta;   // ratio of indices of refraction (inside / outside)
00047     RefractionClosure() : BSDFClosure(Labels::SINGULAR, Back) { }
00048 
00049     void setup() {}
00050 
00051     bool mergeable (const ClosurePrimitive *other) const {
00052         const RefractionClosure *comp = (const RefractionClosure *)other;
00053         return m_N == comp->m_N && m_eta == comp->m_eta &&
00054             BSDFClosure::mergeable(other);
00055     }
00056 
00057     size_t memsize () const { return sizeof(*this); }
00058 
00059     const char *name () const { return "refraction"; }
00060 
00061     void print_on (std::ostream &out) const {
00062         out << name() << " (";
00063         out << "(" << m_N[0] << ", " << m_N[1] << ", " << m_N[2] << "), ";
00064         out << m_eta;
00065         out << ")";
00066     }
00067 
00068     Color3 eval_reflect (const Vec3 &omega_out, const Vec3 &omega_in, float& pdf) const
00069     {
00070         return Color3 (0, 0, 0);
00071     }
00072 
00073     Color3 eval_transmit (const Vec3 &omega_out, const Vec3 &omega_in, float& pdf) const
00074     {
00075         return Color3 (0, 0, 0);
00076     }
00077 
00078     float albedo (const Vec3 &omega_out) const
00079     {
00080         return 1.0f;
00081     }
00082 
00083     ustring sample (const Vec3 &Ng,
00084                  const Vec3 &omega_out, const Vec3 &domega_out_dx, const Vec3 &domega_out_dy,
00085                  float randu, float randv,
00086                  Vec3 &omega_in, Vec3 &domega_in_dx, Vec3 &domega_in_dy,
00087                  float &pdf, Color3 &eval) const
00088     {
00089         Vec3 R, dRdx, dRdy;
00090         Vec3 T, dTdx, dTdy;
00091         bool inside;
00092 
00093         fresnel_dielectric(m_eta, m_N,
00094                            omega_out, domega_out_dx, domega_out_dy,
00095                            R, dRdx, dRdy,
00096                            T, dTdx, dTdy,
00097                            inside);
00098 
00099         if (!inside) {
00100             pdf = 1;
00101             eval.setValue(1.0f, 1.0f, 1.0f);
00102             omega_in = T;
00103             domega_in_dx = dTdx;
00104             domega_in_dy = dTdy;
00105         }
00106 
00107         return Labels::TRANSMIT;
00108     }
00109 };
00110 
00111 ClosureParam bsdf_refraction_params[] = {
00112     CLOSURE_VECTOR_PARAM(RefractionClosure, m_N),
00113     CLOSURE_FLOAT_PARAM (RefractionClosure, m_eta),
00114     CLOSURE_STRING_KEYPARAM("label"),
00115     CLOSURE_FINISH_PARAM(RefractionClosure) };
00116 
00117 CLOSURE_PREPARE(bsdf_refraction_prepare, RefractionClosure)
00118 
00119 CCL_NAMESPACE_END
00120