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
108 lines
3.8 KiB
C++
108 lines
3.8 KiB
C++
/*
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* Adapted from Open Shading Language with this license:
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*
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* Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al.
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* All Rights Reserved.
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*
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* Modifications Copyright 2011, Blender Foundation.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of Sony Pictures Imageworks nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <OpenImageIO/fmath.h>
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#include <OSL/genclosure.h>
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#include "osl_closures.h"
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CCL_NAMESPACE_BEGIN
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using namespace OSL;
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/// Variable cone emissive closure
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///
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/// This primitive emits in a cone having a configurable
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/// penumbra area where the light decays to 0 reaching the
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/// outer_angle limit. It can also behave as a lambertian emitter
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/// if the provided angles are PI/2, which is the default
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///
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class GenericEmissiveClosure : public EmissiveClosure {
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public:
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GenericEmissiveClosure() { }
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void setup() { }
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size_t memsize () const { return sizeof(*this); }
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const char *name () const { return "emission"; }
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void print_on (std::ostream &out) const {
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out << name() << "()";
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}
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Color3 eval (const Vec3 &Ng, const Vec3 &omega_out) const
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{
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float cosNO = fabsf(Ng.dot(omega_out));
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float res = cosNO > 0 ? 1.0f / float(M_PI) : 0.0f;
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return Color3(res, res, res);
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}
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void sample (const Vec3 &Ng, float randu, float randv,
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Vec3 &omega_out, float &pdf) const
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{
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// We don't do anything sophisticated here for the step
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// We just sample the whole cone uniformly to the cosine
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Vec3 T, B;
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make_orthonormals(Ng, T, B);
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float phi = 2 * (float) M_PI * randu;
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float cosTheta = sqrtf(1.0f - 1.0f * randv);
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float sinTheta = sqrtf(1.0f - cosTheta * cosTheta);
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omega_out = (cosf(phi) * sinTheta) * T +
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(sinf(phi) * sinTheta) * B +
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cosTheta * Ng;
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pdf = 1.0f / float(M_PI);
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}
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/// Return the probability distribution function in the direction omega_out,
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/// given the parameters and the light's surface normal. This MUST match
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/// the PDF computed by sample().
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float pdf (const Vec3 &Ng,
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const Vec3 &omega_out) const
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{
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float cosNO = Ng.dot(omega_out);
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return cosNO > 0 ? 1.0f / float(M_PI) : 0.0f;
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}
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};
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ClosureParam closure_emission_params[] = {
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CLOSURE_STRING_KEYPARAM("label"),
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CLOSURE_FINISH_PARAM(GenericEmissiveClosure) };
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CLOSURE_PREPARE(closure_emission_prepare, GenericEmissiveClosure)
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CCL_NAMESPACE_END
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