Add an example for ray_intersection

AABB_tree/examples/AABB_tree/AABB_ray_intersection.cpp

@@ -0,0 +1,65 @@
+#include <algorithm>
+#include <iterator>
+#include <boost/functional/value_factory.hpp>
+#include <boost/timer/timer.hpp>
+
+#include <CGAL/Simple_cartesian.h>
+#include <CGAL/BVH_tree.h>
+#include <CGAL/BVH_bbox_traits_3.h>
+#include <CGAL/boost/graph/graph_traits_Polyhedron_3.h>
+#include <CGAL/BVH_face_graph_triangle_primitive.h>
+
+#include <CGAL/algorithm.h>
+#include <CGAL/point_generators_3.h>
+#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
+
+typedef CGAL::Epeck K;
+typedef K::FT FT;
+typedef K::Point_3 Point;
+typedef K::Vector_3 Vector;
+typedef K::Segment_3 Segment;
+typedef K::Ray_3 Ray;
+typedef CGAL::Polyhedron_3<K> Polyhedron;
+typedef CGAL::BVH_face_graph_triangle_primitive<Polyhedron> Primitive;
+typedef CGAL::BVH_bbox_traits_3<K, Primitive> Traits;
+typedef CGAL::BVH_tree<Traits> Tree;
+typedef Tree::Primitive_id Primitive_id;
+
+int main()
+{
+  Point p(1.0, 0.0, 0.0);
+  Point q(0.0, 1.0, 0.0);
+  Point r(0.0, 0.0, 1.0);
+  Point s(0.0, 0.0, 0.0);
+  Polyhedron polyhedron;
+  polyhedron.make_tetrahedron(p, q, r, s);
+
+  Tree tree(faces(polyhedron).first, faces(polyhedron).second, polyhedron);
+
+
+  const int NB_RAYS = 1000;
+  std::vector<Point> v1, v2;
+  v1.reserve(NB_RAYS); v2.reserve(NB_RAYS);
+
+  const float r = 2.0;
+  // Generate NB_RAYS*2 points that lie on a sphere of radius r.
+  CGAL::Random rand = CGAL::Random(23); // fix the seed to yield the same results each run
+  CGAL::cpp11::copy_n(CGAL::Random_points_on_sphere_3<Point>(r, rand), NB_RAYS, std::back_inserter(v1));
+  CGAL::cpp11::copy_n(CGAL::Random_points_on_sphere_3<Point>(r, rand), NB_RAYS, std::back_inserter(v2));
+
+  // Generate NB_RAYS using v1 as source and v2 as target.
+  std::vector<Ray> rays;
+  rays.reserve(NB_RAYS);
+  std::transform(v1.begin(), v1.end(), v2.begin(),
+                 std::back_inserter(rays), boost::value_factory<Ray>());
+
+  std::vector< boost::optional<Tree::template Intersection_and_primitive_id<Ray>::Type > >
+    intersections;
+
+  // Calculate intersections between rays and primitives.
+  for(std::vector<Ray>::iterator it = rays.begin(); it != rays.end(); ++it) {
+    prims2.push_back(tree.ray_intersection(*it, polyhedron.facets_begin()));
+  }
+
+  return 0;
+}