added extinction coefficient

src/radiator.cpp

@@ -9,7 +9,7 @@ bool radiator::scatter(
   double& fraction_reflected, ray& r_reflected,
   double& fraction_refracted, ray& r_refracted
 ) const{
-  r_reflected = ray(rec.p, r_in.direction(), r_in.get_amplitude(), r_in.optical_path_to(rec.t), r_in.refractive_index_current(), r_in.get_phaseflips(), r_in.get_bounces_left() - 1);
+  r_reflected = ray(rec.p, r_in.direction(), r_in.get_amplitude_at(rec.t), r_in.optical_path_to(rec.t), r_in.refractive_index_current(), 0., r_in.get_phaseflips(), r_in.get_bounces_left() - 1);
   r_reflected.set_source(sourceID);
   fraction_reflected = 1.;
   return false;