static BidirPathVertex sample(const Scene& scene,
const Sensor& sensor,
const Vec2f& lensSample,
const Vec2f& imageSample) {
RaySample raySample;
Intersection I;
float positionPdf, directionPdf, intersectionPdfWrtArea,
sampledPointToIncidentDirectionJacobian;
auto We = sensor.sampleExitantRay(scene, lensSample, imageSample, raySample, positionPdf, directionPdf, I,
sampledPointToIncidentDirectionJacobian, intersectionPdfWrtArea);
if(We == zero<Vec3f>() || raySample.pdf == 0.f) {
return {};
}
We /= raySample.pdf;
if(!I) {
return {
I,
BSDF(),
ScatteringEvent::Emission,
0.f,
directionPdf,
0.f,
raySample.pdf,
We * I.Le,
0u,
false
};
}
return {
I,
BSDF(-raySample.value.dir, I, scene),
ScatteringEvent::Emission,
sampledPointToIncidentDirectionJacobian,
directionPdf,
intersectionPdfWrtArea,
positionPdf * intersectionPdfWrtArea,
We,
1u,
false
};
}
static BSDF init_fresnel (const Vector3D& normal_, const Color& kr_, const Color& kt_, float ior_) {
return BSDF (normal_, FRESNEL,
Color (0.f), Color (0.f), 0.f,
kr_, kt_, ior_);
}
static BSDF init_pure_refl (const Vector3D& normal_, const Color& kd_, const Color& kr_) {
return BSDF (normal_, PURE_REFL,
kd_, Color (0.f), 0.f,
kr_, Color (0.f), 1.3f); /** hack for the IOR, should use different Fresnel equations */
}
static BSDF init_blinn_phong (const Vector3D& normal_, const Color& kd_,
const Color& ks_, float shininess_) {
return BSDF (normal_, BLINN_PHONG,
kd_, ks_, shininess_,
Color (0.f), Color (0.f), 0.f);
}
static BSDF init_diffuse (const Vector3D& normal_, const Color& kd_) {
return BSDF (normal_, DIFFUSE,
kd_, Color (0.f), 0.f,
Color (0.f), Color (0.f), 0.f);
}
