PBRT
/home/felix/UBC/projects/AdaptiveLightfieldSampling/pbrt_v2/src/volumes/homogeneous.h
00001 
00002 /*
00003     pbrt source code Copyright(c) 1998-2012 Matt Pharr and Greg Humphreys.
00004 
00005     This file is part of pbrt.
00006 
00007     Redistribution and use in source and binary forms, with or without
00008     modification, are permitted provided that the following conditions are
00009     met:
00010 
00011     - Redistributions of source code must retain the above copyright
00012       notice, this list of conditions and the following disclaimer.
00013 
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 
00018     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
00019     IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
00020     TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
00021     PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
00022     HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00023     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00024     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00025     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00026     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00027     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00028     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00029 
00030  */
00031 
00032 #if defined(_MSC_VER)
00033 #pragma once
00034 #endif
00035 
00036 #ifndef PBRT_VOLUMES_HOMOGENEOUS_H
00037 #define PBRT_VOLUMES_HOMOGENEOUS_H
00038 
00039 // volumes/homogeneous.h*
00040 #include "volume.h"
00041 
00042 // HomogeneousVolumeDensity Declarations
00043 class HomogeneousVolumeDensity : public VolumeRegion {
00044 public:
00045     // HomogeneousVolumeDensity Public Methods
00046     HomogeneousVolumeDensity(const Spectrum &sa, const Spectrum &ss, float gg,
00047             const Spectrum &emit, const BBox &e, const Transform &v2w) {
00048         WorldToVolume = Inverse(v2w);
00049         sig_a = sa;
00050         sig_s = ss;
00051         g = gg;
00052         le = emit;
00053         extent = e;
00054     }
00055     BBox WorldBound() const {
00056         return Inverse(WorldToVolume)(extent);
00057     }
00058     bool IntersectP(const Ray &r, float *t0, float *t1) const {
00059         Ray ray = WorldToVolume(r);
00060         return extent.IntersectP(ray, t0, t1);
00061     }
00062     Spectrum sigma_a(const Point &p, const Vector &, float) const {
00063         return extent.Inside(WorldToVolume(p)) ? sig_a : 0.;
00064     }
00065     Spectrum sigma_s(const Point &p, const Vector &, float) const {
00066         return extent.Inside(WorldToVolume(p)) ? sig_s : 0.;
00067     }
00068     Spectrum sigma_t(const Point &p, const Vector &, float) const {
00069         return extent.Inside(WorldToVolume(p)) ? (sig_a + sig_s) : 0.;
00070     }
00071     Spectrum Lve(const Point &p, const Vector &, float) const {
00072         return extent.Inside(WorldToVolume(p)) ? le : 0.;
00073     }
00074     float p(const Point &p, const Vector &wi, const Vector &wo, float) const {
00075         if (!extent.Inside(WorldToVolume(p))) return 0.;
00076         return PhaseHG(wi, wo, g);
00077     }
00078     Spectrum tau(const Ray &ray, float, float) const {
00079         float t0, t1;
00080         if (!IntersectP(ray, &t0, &t1)) return 0.;
00081         return Distance(ray(t0), ray(t1)) * (sig_a + sig_s);
00082     }
00083 private:
00084     // HomogeneousVolumeDensity Private Data
00085     Spectrum sig_a, sig_s, le;
00086     float g;
00087     BBox extent;
00088     Transform WorldToVolume;
00089 };
00090 
00091 
00092 HomogeneousVolumeDensity *CreateHomogeneousVolumeDensityRegion(const Transform &volume2world,
00093         const ParamSet &params);
00094 
00095 #endif // PBRT_VOLUMES_HOMOGENEOUS_H