RGBColor
Transparent::shade(ShadeRec& sr) {
if (ior_tex != NULL) {
//get current ior
float i = 0;
i = ior_tex->get_color(sr).average()*1.2;
set_ior(i);
}
RGBColor L(SV_Phong::shade(sr)); // direct illumination
Vector3D wo = -sr.ray.d;
Vector3D wi;
RGBColor fr = reflective_brdf->sample_f(sr, wo, wi);
Ray reflected_ray(sr.hit_point, wi);
if (specular_btdf->tir(sr))
L += sr.w.tracer_ptr->trace_ray(reflected_ray, sr.depth + 1);
else {
Vector3D wt;
RGBColor ft = specular_btdf->sample_f(sr,wo,wt);
Ray transmitted_ray(sr.hit_point, wt);
L += fr * sr.w.tracer_ptr->trace_ray(reflected_ray, sr.depth + 1) * fabs(sr.normal * wi);
L += ft * sr.w.tracer_ptr->trace_ray(transmitted_ray, sr.depth + 1) * fabs(sr.normal * wt);
}
return (L);
}
RGBColor Dielectric::shade(ShadeRec& sr)const
{
RGBColor L(Phong::shade(sr));
Vector3D wi;
Vector3D wo(-sr.ray.d);
RGBColor fr = fresnel_brdf->sample_f(sr, wo, wi); // computes wi
Ray reflected_ray(sr.hit_point, wi);
double t;
RGBColor Lr, Lt;
float ndotwi = sr.normal * wi;
if(fresnel_btdf->tir(sr))
{ // total internal reflection
if (ndotwi < 0.0)
{
// reflected ray is inside
Lr = sr.w.tracer_ptr->trace_ray(reflected_ray, t, sr.depth + 1);
L += cf_in.powc(t) * Lr; // inside filter color
}
else
{
// reflected ray is outside
Lr = sr.w.tracer_ptr->trace_ray(reflected_ray, t, sr.depth + 1); // kr = 1
L += cf_out.powc(t) * Lr; // outside filter color
}
}
else
{ // no total internal reflection
Vector3D wt;
RGBColor ft = fresnel_btdf->sample_f(sr, wo, wt); // computes wt
Ray transmitted_ray(sr.hit_point, wt);
float ndotwt = sr.normal * wt;
if (ndotwi < 0.0)
{
// reflected ray is inside
Lr = fr * sr.w.tracer_ptr->trace_ray(reflected_ray, t, sr.depth + 1) * fabs(ndotwi);
L += cf_in.powc(t) * Lr; // inside filter color
// transmitted ray is outside
Lt = ft * sr.w.tracer_ptr->trace_ray(transmitted_ray, t, sr.depth + 1) * fabs(ndotwt);
L += cf_out.powc(t) * Lt; // outside filter color
}
else
{
// reflected ray is outside
Lr = fr * sr.w.tracer_ptr->trace_ray(reflected_ray, t, sr.depth + 1) * fabs(ndotwi);
L += cf_out.powc(t) * Lr; // outside filter color
// transmitted ray is inside
Lt = ft * sr.w.tracer_ptr->trace_ray(transmitted_ray, t, sr.depth + 1) * fabs(ndotwt);
L += cf_in.powc(t) * Lt; // inside filter color
}
}
return (L);
}