phase flips fixed (in amplitude), removed extinction

src/dielectric.cpp

@@ -3,7 +3,7 @@
 #include <cassert>
 
 dielectric::dielectric(double index_of_refraction_inside, double index_of_refraction_outside, double extinction_inside)
-: ir_inside(index_of_refraction_inside), ir_outside(index_of_refraction_outside), extinction_inside(extinction_inside){
+: ir_inside(index_of_refraction_inside), ir_outside(index_of_refraction_outside){
 
 }
 
@@ -23,22 +23,17 @@ bool dielectric::scatter(
   vec3 unit_direction = unit_vector(r_in.direction());
   double refraction_ratio;
   double ir_in, ir_out;
-  double extinct_in, extinct_out;
   vec3 relevant_normal;
   if(rec.inbound){
     refraction_ratio = ir_outside / ir_inside;
     ir_in = ir_outside;
     ir_out = ir_inside;
-    extinct_in = 0.;
-    extinct_out = extinction_inside;
     relevant_normal = rec.normal;
   }
   else{
     refraction_ratio = ir_inside / ir_outside;
     ir_in = ir_inside;
     ir_out = ir_outside;
-    extinct_in = extinction_inside;
-    extinct_out = 0.;
     relevant_normal = -rec.normal;
   }
 
@@ -57,17 +52,23 @@ bool dielectric::scatter(
     double sin_theta_refracted = refraction_ratio * sin_theta;
     double cos_theta_refracted = std::sqrt(1. - sin_theta_refracted * sin_theta_refracted);
     fraction_reflected = reflectance(cos_theta, cos_theta_refracted, ir_in, ir_out);
-    fraction_refracted = 1. - fraction_reflected;
+    //fraction_refracted = 1. - fraction_reflected;
+    fraction_refracted = transmittance(cos_theta, cos_theta_refracted, ir_in, ir_out);
   }
   else{
     fraction_reflected = 1.;
     fraction_refracted = 0.;
   }
   int phase_flips = r_in.get_phaseflips();
+  /*
+  //Explicit handling of phase flips
   r_reflected = ir_out > ir_in ?
                 ray(rec.p, dir_reflected, fraction_reflected * r_in.get_amplitude_at(rec.t), optical_path_to_p, ir_in, extinct_in, phase_flips + 1, bounces_left - 1) :
                 ray(rec.p, dir_reflected, fraction_reflected * r_in.get_amplitude_at(rec.t), optical_path_to_p, ir_in, extinct_in, phase_flips, bounces_left - 1);
-  r_refracted = ray(rec.p, dir_refracted, fraction_refracted * r_in.get_amplitude_at(rec.t), optical_path_to_p, ir_out, extinct_out, phase_flips, bounces_left - 1);
+  */
+  //Phase flips are absorbed by the reflection amplitude
+  r_reflected = ray(rec.p, dir_reflected, fraction_reflected * r_in.get_amplitude_at(rec.t), optical_path_to_p, ir_in, phase_flips, bounces_left - 1);
+  r_refracted = ray(rec.p, dir_refracted, fraction_refracted * r_in.get_amplitude_at(rec.t), optical_path_to_p, ir_out, phase_flips, bounces_left - 1);
 
   #ifndef NDEBUG
   //if(fraction_reflected > 1.){
@@ -97,11 +98,13 @@ double dielectric::reflectance(double cos_theta_in, double cos_theta_out, double
   //new amplitude reflectance coefficients
   double rs = ( ir_in * cos_theta_in - ir_out * cos_theta_out ) / ( ir_in * cos_theta_in + ir_out * cos_theta_out );
   double rp = ( ir_out * cos_theta_in - ir_in * cos_theta_out ) / ( ir_out * cos_theta_in + ir_in * cos_theta_out );
-  return 0.5 * (rs + rp);
+  //return 0.5 * (rs + rp);
+  return rs;
 }
 
 double dielectric::transmittance(double cos_theta_in, double cos_theta_out, double ir_in, double ir_out) const{
   double ts = 2 * ir_in * cos_theta_in / ( ir_in * cos_theta_in + ir_out * cos_theta_out );
   double tp = 2 * ir_in * cos_theta_in / ( ir_out * cos_theta_in + ir_in * cos_theta_out );
-  return 0.5 * (ts + tp);
+  //return 0.5 * (ts + tp);
+  return ts;
 }