project: Global illumination pathtracer

Details

A simple pathtracer program, capable of producing renderings of simple bodies. The program computes global illumination, by intersecting scene objects, such as luminaries and solid bodies, with idealised surface properies.

  • last updated: August, 2018
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Screenshots

scene_3smpls.bmp scene_1smpl_dark.bmp scene_30smpls.bmp

src > box.cpp

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#include "./defines.hpp"

#include "./box.hpp"
#include "./vec3.hpp"
#include "./ray.hpp"
#include "./object.hpp"
#include "./material.hpp"

namespace raytracer
{
bool box::intersects(const ray& ray, double& length, vec3& normal, material& mat) const
{
  double tmin, tmax, tymin, tymax, tzmin, tzmax, swap;
  double bias= 1e-8;
  tmin = (vmin_.x - ray.origin.x)/(ray.direction.x+bias);
  tmax = (vmax_.x - ray.origin.x)/(ray.direction.x+bias);

   if (tmin > tmax){ swap=tmin; tmin= tmax; tmax= swap;}

   tymin = (vmin_.y - ray.origin.y)/(ray.direction.y+bias);
   tymax = (vmax_.y - ray.origin.y)/(ray.direction.y+bias);

   if (tymin > tymax){ swap=tymin; tymin= tymax; tymax= swap;}
   
   if ((tmin > tymax) || (tymin > tmax)) return false;
   if (tymin > tmin) tmin = tymin;
   if (tymax < tmax) tmax = tymax;

   tzmin = (vmin_.z - ray.origin.z)/(ray.direction.z+bias);
   tzmax = (vmax_.z - ray.origin.z)/(ray.direction.z+bias);

   if (tzmin > tzmax){ swap=tzmin; tzmin= tzmax; tzmax= swap;}
   
   if ((tmin > tzmax) || (tzmin > tmax)) return false;
   if (tzmin > tmin) tmin = tzmin;
   if (tzmax < tmax) tmax = tzmax;

   vec3 lenv= ray.direction.scale(tmin);
   //calc length
   length= lenv.length();

   //calc normal
   vec3 loc_surfp= ray.origin.add(lenv).add(this->pos_.negative());
   double bias2 = 1.000001;   
   
   normal= vec3((int)(loc_surfp.x*bias2/this->halflen_.x),
                (int)(loc_surfp.y*bias2/this->halflen_.y),
                (int)(loc_surfp.z*bias2/this->halflen_.z)
                );
   
   mat= *this->material_;
   return true;
};

}