00001 /*************************************************************************** 00002 * Copyright (C) 1998-2008 by authors (see AUTHORS.txt ) * 00003 * * 00004 * This file is part of LuxRender. * 00005 * * 00006 * Lux Renderer is free software; you can redistribute it and/or modify * 00007 * it under the terms of the GNU General Public License as published by * 00008 * the Free Software Foundation; either version 3 of the License, or * 00009 * (at your option) any later version. * 00010 * * 00011 * Lux Renderer is distributed in the hope that it will be useful, * 00012 * but WITHOUT ANY WARRANTY; without even the implied warranty of * 00013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * 00014 * GNU General Public License for more details. * 00015 * * 00016 * You should have received a copy of the GNU General Public License * 00017 * along with this program. If not, see <http://www.gnu.org/licenses/>. * 00018 * * 00019 * This project is based on PBRT ; see http://www.pbrt.org * 00020 * Lux Renderer website : http://www.luxrender.net * 00021 ***************************************************************************/ 00022 00023 #ifndef LUX_ORENNAYAR_H 00024 #define LUX_ORENNAYAR_H 00025 // orennayar.h* 00026 #include "lux.h" 00027 #include "bxdf.h" 00028 #include "spectrum.h" 00029 00030 namespace lux 00031 { 00032 00033 class OrenNayar : public BxDF { 00034 public: 00035 // OrenNayar Public Methods 00036 SWCSpectrum f(const Vector &wo, const Vector &wi) const; 00037 OrenNayar(const SWCSpectrum &reflectance, float sig) 00038 : BxDF(BxDFType(BSDF_REFLECTION | BSDF_DIFFUSE)), 00039 R(reflectance) { 00040 float sigma = Radians(sig); 00041 float sigma2 = sigma*sigma; 00042 A = 1.f - (sigma2 / (2.f * (sigma2 + 0.33f))); 00043 B = 0.45f * sigma2 / (sigma2 + 0.09f); 00044 } 00045 private: 00046 // OrenNayar Private Data 00047 SWCSpectrum R; 00048 float A, B; 00049 }; 00050 00051 }//namespace lux 00052 00053 #endif // LUX_ORENNAYAR_H 00054