Vec3f TraceBase::volumePhaseSample(const Primitive &light,
PathSampleGenerator &sampler,
MediumSample &mediumSample,
const Medium *medium,
int bounce,
const Ray &parentRay)
{
PhaseSample phaseSample;
if (!mediumSample.phase->sample(sampler, parentRay.dir(), phaseSample))
return Vec3f(0.0f);
Ray ray = parentRay.scatter(mediumSample.p, phaseSample.w, 0.0f);
ray.setPrimaryRay(false);
IntersectionTemporary data;
IntersectionInfo info;
Vec3f e = attenuatedEmission(sampler, light, medium, -1.0f, data, info, bounce, false, ray, nullptr);
if (e == Vec3f(0.0f))
return Vec3f(0.0f);
Vec3f phaseF = e*phaseSample.weight;
phaseF *= SampleWarp::powerHeuristic(phaseSample.pdf, light.directPdf(_threadId, data, info, mediumSample.p));
return phaseF;
}
Vec3f TraceBase::bsdfSample(const Primitive &light,
SurfaceScatterEvent &event,
const Medium *medium,
int bounce,
const Ray &parentRay)
{
event.requestedLobe = BsdfLobes::AllButSpecular;
if (!event.info->bsdf->sample(event, false))
return Vec3f(0.0f);
if (event.weight == 0.0f)
return Vec3f(0.0f);
Vec3f wo = event.frame.toGlobal(event.wo);
if (!isConsistent(event, wo))
return Vec3f(0.0f);
bool geometricBackside = (wo.dot(event.info->Ng) < 0.0f);
medium = event.info->primitive->selectMedium(medium, geometricBackside);
Ray ray = parentRay.scatter(event.info->p, wo, event.info->epsilon);
ray.setPrimaryRay(false);
IntersectionTemporary data;
IntersectionInfo info;
Vec3f e = attenuatedEmission(*event.sampler, light, medium, -1.0f, data, info, bounce, true, ray, nullptr);
if (e == Vec3f(0.0f))
return Vec3f(0.0f);
Vec3f bsdfF = e*event.weight;
bsdfF *= SampleWarp::powerHeuristic(event.pdf, light.directPdf(_threadId, data, info, event.info->p));
return bsdfF;
}
