RGB BRDFToBTDF::f(const Vector &wo, const Vector &wi) const {
return mBrdf->f(wo, otherHemisphere(wi));
}
Spectrum BRDFToBTDF::Sample_f(const Vector &wo, Vector *wi,
float u1, float u2, float *pdf) const {
Spectrum f = brdf->Sample_f(wo, wi, u1, u2, pdf);
*wi = otherHemisphere(*wi);
return f;
}
RGB BRDFToBTDF::Sample_f(const Vector& wo, Vector* wi, float u1, float u2,
float *pdf) const {
RGB ret = mBrdf->Sample_f(wo, wi, u1, u2, pdf);
*wi = otherHemisphere(*wi); //改变采样后的入射光的方向
return ret;
}
// BxDF Method Definitions
Spectrum BRDFToBTDF::f(const Vector &wo,
const Vector &wi) const {
return brdf->f(wo, otherHemisphere(wi));
}