const ColorRGB Scene3D::traceRay(const Ray& ray, int depth) const
{
float closest_t_value = NO_INTERSECT;
const SceneObject* closest_object = findClosest(ray, closest_t_value);
if (closest_object == 0)
return ColorRGB(0,0,0);
ColorRGB retColor(0,0,0);
for (int i = 0; i < lights.size(); i++)
{
Vector3D normL = ((*lights[i]).get_position()-ray.getPointAt(closest_t_value)).normalize();
Vector3D normN = (*closest_object).surface_normal(ray.getPointAt(closest_t_value));
retColor += (*lights[i]).get_color()*(*closest_object).get_color()*std::max((normL*normN),float(0));
if (depth < 6 && (*closest_object).get_reflectivity() > 0)
{
Ray reflected_ray = ray.reflect(ray.getPointAt(closest_t_value), (*closest_object).surface_normal(ray.getPointAt(closest_t_value)));
ColorRGB reflection_color = traceRay(reflected_ray, depth+1);
retColor+= (*closest_object).get_reflectivity()*reflection_color;
}
}
return retColor;
}
Spectrum IntegratorHelpers::radianceDirect(const Scene* scene, const Ray& ray,
const RaySurfIntersection& hit, const IntegratorHelpers::SpectralStrategy& ss)
{
//Memory for output spectrum
//TODO: Remove all dynamic memory allocations from rendering inner loop
//...for now this is still in here for east of implementation
float* buf = new float[ss.numSpectralSamples];
for(int i = 0; i < ss.numSpectralSamples; i++){
buf[i] = 0.0f;
}
//Return spectrum
Spectrum retColor(buf, ss.nmMin, ss.nmMax, ss.nmStep, ss.numSpectralSamples);
//Create relavent params
const Vector omega_o(-ray.getDir());
const Vector vecN(hit.n.x, hit.n.y, hit.n.z);
const AccelStructure* geom = scene->getSceneGeom(); //Scene acceleration structure
const bool isEmitter = hit.shp->isEmitter();
const Point hitLocWS(hit.locWS);
//Determine the maximum number of light samples we will make
//and allocate this memory OUTSIDE of the light loop
int NLightSampsMax = -1;
for(size_t i = 0; i < scene->getNumLights(); i++){
NLightSampsMax = std::max<int>(
NLightSampsMax,
scene->getLight(i)->getRecNumVisibilitySamples());
}
Point* samps = new Point[NLightSampsMax];
//Process each light individually
for(size_t i = 0; i < scene->getNumLights(); i++){
Light* l = scene->getLight(i);
//Skip sampling the light itself if the geometry is an emitter
if(isEmitter && hit.shp->getEmitter() == l){
continue;
}
//Sample the light source potentially many times
const int N = l->getRecNumVisibilitySamples();
l->getSamples(samps, N);
//Loop over all light samples
const float invNumSamps = 1.0f / float(N);
for(int j = 0; j < N; j++){
//Check if we can see the light
VisibilityTester visTest(hitLocWS, samps[j], l->getGeom(),
geom, DFLT_RAY_MOVE_EPSILON);
//visTest.r is a ray to the light from hitLocWS
//Get the incident radiance from the light at the hit location
Spectrum L = l->sampleIncidentRadiance(hitLocWS, vecN, samps[j]);
//TODO: "continue" here if the spectrum is black...is this any faster?
//If we saw the light, add its contribution
bool sawLight = visTest.visible(NULL);
if(sawLight){
//Vector to light
const Vector omega_i(visTest.r.getDir());
//Geomety term (solid angle)
const Vector Nvec = hit.n;
const float G = GeomUtils::absDotProd(omega_i, Nvec);
//Technically, the above G is not correct! TODO
//const Vector v = (samps[j] - hitLocWS);
//const float r = v.magnitude();
//const float G = GeomUtils::absDotProd(omega_i, Nvec) / (r*r);
//Transform vectors into local BRDF frame
/*
Vector w_i_brdfCS = BRDFCoordHelpers::worldCSToBrdfCS(omega_i,
Nvec, hit.tangent, Nvec.cross(hit.tangent));
Vector w_o_brdfCS = BRDFCoordHelpers::worldCSToBrdfCS(omega_o,
Nvec, hit.tangent, Nvec.cross(hit.tangent));
*/
//Evaluate BRDF term at each wavelength
float nm = ss.nmMin;
BRDF* brdf = hit.shp->getBRDF();
for(int i = 0; i < ss.numSpectralSamples; i++){
buf[i] = brdf->f(omega_i, omega_o, nm);
//buf[i] = brdf->f(w_i_brdfCS, w_o_brdfCS, nm);
nm += ss.nmStep;
}
//Create a "spectrum" of BRDF values
Spectrum brdfSpec(buf, ss.nmMin, ss.nmMax, ss.nmStep,
ss.numSpectralSamples);
//Light term
retColor = retColor + (L * G * invNumSamps * brdfSpec);
}
}
}
//All done!
delete[] samps; samps = NULL;
delete[] buf; buf = NULL;
return retColor;
}
