double PointLight::getCumulativeIndex() {
if (m_refractive_index > 0) return m_refractive_index;
//calculate the refractive index
std::default_random_engine generator;
//randomly pick a ray
ray r = getPhoton(generator);
//trace the ray
multiset<const SceneObject*> objs;
isect i;
while (scene->intersect(r, i)) {
if (i.obj->hasInterior()) { //only care about volumetric shapes
if (r.getDirection().dot(i.N) > RAY_EPSILON) { //going out of the material
if (objs.find(i.obj) == objs.end()) { //not found in the set
//that must be one.
m_refractive_index *= i.getMaterial().index;
r = ray(r.at(i.t), r.getDirection());
}
else { //found the same object already
objs.erase(i.obj);
r = ray(r.at(i.t), r.getDirection());
}
}
else { //going into the material
objs.insert(i.obj);
r = ray(r.at(i.t), r.getDirection());
}
}
}
return m_refractive_index;
}
void PhotonMap::renderGL()
{
glBegin(GL_POINTS);
for (int i = 0; i < stored_photons; ++i)
{
Photon ph = getPhoton(i);
glVertex3f(ph.pos[0], ph.pos[1], ph.pos[2]);
}
glEnd();
}
