CGAL 5.6 - 3D Fast Intersection and Distance Computation (AABB Tree)
AABB_tree/AABB_ray_shooting_example.cpp
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/AABB_tree.h>
#include <CGAL/AABB_traits.h>
#include <CGAL/AABB_face_graph_triangle_primitive.h>
#include <CGAL/Polygon_mesh_processing/compute_normal.h>
#include <CGAL/Polygon_mesh_processing/orientation.h>
#include <iostream>
#include <fstream>
typedef K::FT FT;
typedef K::Point_3 Point;
typedef K::Vector_3 Vector;
typedef K::Ray_3 Ray;
typedef CGAL::Surface_mesh<Point> Mesh;
typedef boost::graph_traits<Mesh>::face_descriptor face_descriptor;
typedef boost::graph_traits<Mesh>::halfedge_descriptor halfedge_descriptor;
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 std::string filename = (argc > 1) ? argv[1] : CGAL::data_file_path("meshes/tetrahedron.off");
Mesh mesh;
if(!CGAL::IO::read_polygon_mesh(filename, mesh))
{
std::cerr << "Invalid input." << std::endl;
return 1;
}
Tree tree(faces(mesh).first, faces(mesh).second, mesh);
double d = CGAL::Polygon_mesh_processing::is_outward_oriented(mesh)?-1:1;
for(face_descriptor fd : faces(mesh))
{
halfedge_descriptor hd = halfedge(fd,mesh);
Point p = CGAL::centroid(mesh.point(source(hd,mesh)),
mesh.point(target(hd,mesh)),
mesh.point(target(next(hd,mesh),mesh)));
Vector v = CGAL::Polygon_mesh_processing::compute_face_normal(fd,mesh);
Ray ray(p,d * v);
Skip skip(fd);
Ray_intersection intersection = tree.first_intersection(ray, skip);
if(intersection)
{
if(boost::get<Point>(&(intersection->first))){
const Point* p = boost::get<Point>(&(intersection->first) );
std::cout << *p << std::endl;
}
}
}
std::cerr << "done" << std::endl;
return 0;
}