PhotonTracing.cc

Go to the documentation of this file.

#include <gra/reflection/PhotonTracing.h>
#include <esg/visitor/PhotonMapBhvVisitor.h>
#include <esg/energy/PhotonMapEnergy.h>

using namespace gra;

void PhotonTracing::_store_photon(PointEnv& surr, bool caustics)
{
    AutoPtr<EnergyCoat>* pAMap = surr.pVisitableObj->getEnergyState();
    if (!pAMap) return;

    EnergyCoat* pCoat = pAMap->origObject();
    if (!pCoat) return;

    PhotonMapEnergy* pMap = dynamic_cast<PhotonMapEnergy*>(pCoat);
    if (!pMap) return;
    
    // we have a photon map
    PhotonMapBhvVisitor pmbVisitor;
    surr.pVisitableObj->inspectAttributes(pmbVisitor);
    if (!pmbVisitor.behaviour()) return;
    
    if (caustics && pmbVisitor.behaviour()->acceptsCaustics()) {
        pMap->storeCausticPhoton(Photon(surr.intersection,
                                        surr.viewerDir,
                                        surr.energy));
        return;
    }
    
    if (pmbVisitor.behaviour()->acceptsGlobalPhotons()) 
        pMap->storeGlobalPhoton(Photon(surr.intersection,
                                       surr.viewerDir,
                                       surr.energy));
}

void PhotonTracing::_illuminate(PointEnv& surr,
                                unsigned  actDepth,
                                bool      firstObjHit,
                                Color3f&  unused)
{
    if (actDepth >= _maxDepth) return;

    /*
     * We suppose that the given "surr" contains proper point of intersection,
     * normal vector and associated primitive
     *
     * Transform point of intersection and properly orient normal
     */
    _check_point_of_intersection(surr);

    /*
     * Inspect attributes that are necessary for local illumination,
     * reflection and transmission. Set correct BRDF and emittance for local
     * reflection. If the point of interest is the second point of refraction
     * ray then previous material is used (the object was not changed)
     */
    MatVisitor* pMatVisitor = _check_material(surr.pVisitableObj, firstObjHit);

    const Vector3& refl   = pMatVisitor->reflection();
    const Vector3& transp = pMatVisitor->transparency();
    if (refl.x || refl.y || refl.z || transp.x || transp.y || transp.z) {
        /*
         * Traverse random direction using russian roulette
         */
        if (actDepth < _maxDepth) 
            _cast_secondary_rays(surr, actDepth, firstObjHit,
                                 unused, *pMatVisitor);
    } else {
        /*
         * store photon falled on a diffuse surface
         */
        _store_photon(surr, false);
    }
}


// --------- public ----------------

Color3f* PhotonTracing::illuminatePoint(PointEnv & env)
{
    if (!(_pDiffuseBRDF || _pSpecularBRDF)) return NULL;
    if (!(_pScene && _pScene->root())) return NULL;
    if (!_pIntersector) return NULL;
    if (!(env.mask & (ENV_HAVE_INTERSECTION|
                      ENV_HAVE_NORMAL|
                      ENV_HAVE_ASOC_PRIMITIVE|
                      ENV_HAVE_VIEWER_DIR))) return NULL;
    
    if (! env.pVisitableObj) return NULL;

    if (!(env.mask & ENV_HAVE_ENERGY)) env.energy.set(1.,1.,1.);

    Color3f* pColor = new Color3f(0.0, 0.0, 0.0);

#ifdef ESG_STATISTICS
    _numReflections = (_numRefractions = 0);
#endif
    _illuminate(env, 0, true, *pColor);

#ifdef ESG_STATISTICS
    ((Counter*)Statistics::instance()->get(Statistics::OID_REFLECTIONS)->receptor())->add(_numReflections);
    ((Counter*)Statistics::instance()->get(Statistics::OID_REFRACTIONS)->receptor())->add(_numRefractions);
#endif


    return pColor;
}

---