static Color3 finalGathering(KdTree<Photon> *map , Scene& scene ,
Intersection& inter , RNG& rng , const Vector3& wo ,
int gatherSamples , int knn , Real maxSqrDis)
{
Color3 res = Color3(0.0 , 0.0 , 0.0);
for (int i = 0; i < gatherSamples; i++)
{
Real pdf;
Vector3 wi = sampleCosHemisphere(rng.randVector3() , &pdf);
Ray ray = Ray(inter.p + wi * EPS , wi);
Intersection _inter;
Geometry *_g = scene.intersect(ray , _inter);
if (_g == NULL)
continue;
Color3 tmp = estimate(map , 0 , knn , scene , _inter , -wi , maxSqrDis);
BSDF bsdf(wi , _inter , scene);
Real cosine , bsdfPdf;
Color3 brdf = bsdf.f(scene , wo , cosine , &bsdfPdf);
if (brdf.isBlack())
continue;
pdf *= bsdfPdf;
res = res + (tmp | brdf) * (cosine / pdf);
}
res = res / gatherSamples;
return res;
}
void Material::samplePhong(Isect &isect, const Vector3d &out, Vector3d &in, double &pdf) const
{
in = sampleCosHemisphere(isect.normal());
}