Ray Tracing Rendering System

Basic System

Image *img = NULL;
View *view = NULL;
Light *lights = NULL;
OBJECT *objs = NULL;
Matrix4 mclip, mdpy;
RContext *rc;


main(int argc, char **argv)
{
  Color c; int u, v;
  Ray r; Inode *l;

  read_scene();
  init_render();

  for (v = view->sc_min.y; v < view->sc_max.y; v += 1) {
    for (u = view->sc_min.x; u < view->sc_max.x; u += 1) {
      if (l = ray_cast(objs, (r = ray_transform(ray_view(u, v), mclip))))
        c = point_shade(ray_point(r, l->t), l->n,
                        view->center, rc, lights, l->m);
      else
        c = BG_COL;
      inode_free(l);
      img_puti(img, u, v, col_dpymap(c));
    }
  }
  img_write(img,"stdout",0);
  exit(0);
}


Ray ray_view(int u, int v)
{
  Vector4 w = v4_m4mult(v4_make((Real)(u),(Real)(v),view->sc_max.z,1), mdpy);
  return ray_make(v3_v4conv(v4_m4mult(v4_make(0, 0, 1, 0), mdpy)),
                  v3_unit(v3_make(w.x, w.y, w.z)));
}


void init_render(void)
{
  if (view == NULL)
    view = initview();
  mclip = m4_m4prod(view->Vinv, view->Cinv);
  mdpy = m4_m4prod(view->Pinv,view->Sinv);

  if (img == NULL)
    img = img_init(view->sc_max.x, view->sc_max.y, 0);
  if (lights == NULL)
    LIST_INSERT(lights, light_ambient(0.5), Light);
  rc = NEWSTRUCT(RContext);
}  

Input-Output

scene{
        camera = view {
                from = {0, 0, -3}, to = {0, 0, 0}, roll = 0, fov = 60
                },
        
        light = dist_light {direction = {0, 1, 1} },

        object = csgobj{ 
                material = plastic { },
                shape = csg_prim{ sphere { center = {0, 0, 0}}}},
};

Image File (stdout)

Extension Options

• Include global illumination with recursive ray tracing.

• Include a ray tracing acceleration method.

• Include polygons.