ray shooting

ray_shooting.cpp

#include <iostream>
#include <fstream>

#include <CGAL/Simple_cartesian.h>
#include <CGAL/AABB_tree.h>
#include <CGAL/AABB_traits.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/AABB_face_graph_triangle_primitive.h>
#include <CGAL/Polygon_mesh_processing/compute_normal.h>

typedef CGAL::Simple_cartesian<double> K;
typedef K::FT FT;
typedef K::Point_3 Point;
typedef K::Vector_3 Vector;
typedef K::Ray_3 Ray;

typedef CGAL::Surface_mesh<Point> Polyhedron;
typedef boost::graph_traits<Polyhedron>::face_descriptor face_descriptor;
typedef boost::graph_traits<Polyhedron>::halfedge_descriptor halfedge_descriptor;

typedef CGAL::AABB_face_graph_triangle_primitive<Polyhedron> Primitive;
typedef CGAL::AABB_traits<K, Primitive> Traits;
typedef CGAL::AABB_tree<Traits> Tree;
typedef boost::optional< Tree::Intersection_and_primitive_id<Ray>::Type > Ray_intersection;


struct Skip {
  face_descriptor fd;

  Skip(const face_descriptor fd)
    : fd(fd)
  {}

  
  bool operator()(const face_descriptor& t) const
  { if(t == fd){
      std::cerr << "ignore" << t  <<std::endl;
    };
    return(t == fd);
  }
  
};

int main(int argc, char* argv[])
{
  const char* filename = (argc > 1) ? argv[1] : "data/bunny.off";
  std::ifstream input(filename);
  Polyhedron polyhedron;
  input >> polyhedron;
  Tree tree( faces(polyhedron).first, faces(polyhedron).second, polyhedron);
  

  BOOST_FOREACH(face_descriptor fd, faces(polyhedron)){
    halfedge_descriptor hd = halfedge(fd,polyhedron);
    Point p = CGAL::centroid(polyhedron.point(source(hd,polyhedron)),
                             polyhedron.point(target(hd,polyhedron)),
                             polyhedron.point(target(next(hd,polyhedron),polyhedron)));
    Vector v = CGAL::Polygon_mesh_processing::compute_face_normal(fd,polyhedron);	
    
    Ray ray(p,v);
    Ray_intersection intersection = tree.first_intersection(ray, Skip(fd));
    if(intersection){
      if(boost::get<Point>(&(intersection->first))){
        Point* p =  boost::get<Point>(&(intersection->first) );

        std::cout <<  p << std::endl;
      }
    }
  }
  std::cerr << "done" << std::endl;
  return 0;
}