added extinction coefficient, removed wrong assertions

src/dielectric.cpp

@@ -2,8 +2,8 @@
 #include <cmath>
 #include <cassert>
 
-dielectric::dielectric(double index_of_refraction_inside, double index_of_refraction_outside)
-: ir_inside(index_of_refraction_inside), ir_outside(index_of_refraction_outside){
+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){
 
 }
 
@@ -23,17 +23,22 @@ 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;
   }
 
@@ -60,9 +65,9 @@ bool dielectric::scatter(
   }
   int phase_flips = r_in.get_phaseflips();
   r_reflected = ir_out > ir_in ?
-                ray(rec.p, dir_reflected, fraction_reflected * r_in.get_amplitude(), optical_path_to_p, ir_in, phase_flips + 1, bounces_left - 1) :
-                ray(rec.p, dir_reflected, fraction_reflected * r_in.get_amplitude(), optical_path_to_p, ir_in, phase_flips, bounces_left - 1);
-  r_refracted = ray(rec.p, dir_refracted, fraction_refracted * r_in.get_amplitude(), optical_path_to_p, ir_out, phase_flips, 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 + 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);
 
   #ifndef NDEBUG
   //if(fraction_reflected > 1.){
@@ -74,9 +79,9 @@ bool dielectric::scatter(
     std::cerr << "refracted ray: origin: " << r_refracted.origin() << ", direction: " << r_refracted.direction() << std::endl;
   //}
   #endif
-  assert(fraction_reflected >= 0. && fraction_refracted >= 0.);
-  assert(fraction_reflected <= 1. && fraction_refracted <= 1.);
-  assert(std::fabs(fraction_refracted + fraction_reflected - 1.) < 0.00000001);
+  //assert(fraction_reflected >= 0. && fraction_refracted >= 0.);
+  //assert(fraction_reflected <= 1. && fraction_refracted <= 1.);
+  //assert(std::fabs(fraction_refracted + fraction_reflected - 1.) < 0.00000001);
   assert(r_reflected.origin().x() == rec.p.x() && r_reflected.origin().y() == rec.p.y() && r_reflected.origin().z() == rec.p.z());
   assert(r_refracted.origin().x() == rec.p.x() && r_refracted.origin().y() == rec.p.y() && r_refracted.origin().z() == rec.p.z());
 

src/dielectric.hpp

@@ -5,7 +5,7 @@
 
 class dielectric: public material{
 public:
-  dielectric(double index_of_refraction_inside, double index_of_refraction_outside);
+  dielectric(double index_of_refraction_inside, double index_of_refraction_outside, double extinction_inside = 0.);
 
   virtual bool scatter(
     const ray& r_in, const hit_record& rec,
@@ -19,6 +19,7 @@ private:
 
   double ir_inside; //index of refraction inside material
   double ir_outside; //index of refraction outside material
+  double extinction_inside; //exponential extinction coefficient inside material
 };
 
 #endif