CGAL 4.7 - 3D Fast Intersection and Distance Computation (AABB Tree): AABB_tree/AABB_polyhedron_facet_distance_example.cpp

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CGAL 4.7 - 3D Fast Intersection and Distance Computation (AABB Tree)

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AABB_tree/AABB_polyhedron_facet_distance_example.cpp
// Author(s) : Pierre Alliez
#include <iostream>
#include <CGAL/Simple_cartesian.h>
#include <CGAL/AABB_tree.h>
#include <CGAL/AABB_traits.h>
#include <CGAL/Polyhedron_3.h>
#include <CGAL/boost/graph/graph_traits_Polyhedron_3.h>
#include <CGAL/AABB_face_graph_triangle_primitive.h>
typedef CGAL::Simple_cartesian<double> K;
typedef K::FT FT;
typedef K::Point_3 Point;
typedef K::Segment_3 Segment;
typedef CGAL::Polyhedron_3<K> Polyhedron;
typedef CGAL::AABB_face_graph_triangle_primitive<Polyhedron> Primitive;
typedef CGAL::AABB_traits<K, Primitive> Traits;
typedef CGAL::AABB_tree<Traits> Tree;
typedef Tree::Point_and_primitive_id Point_and_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);
// constructs AABB tree and computes internal KD-tree
// data structure to accelerate distance queries
Tree tree(faces(polyhedron).first, faces(polyhedron).second, polyhedron);
tree.accelerate_distance_queries();
// query point
Point query(0.0, 0.0, 3.0);
// computes squared distance from query
FT sqd = tree.squared_distance(query);
std::cout << "squared distance: " << sqd << std::endl;
// computes closest point
Point closest = tree.closest_point(query);
std::cout << "closest point: " << closest << std::endl;
// computes closest point and primitive id
Point_and_primitive_id pp = tree.closest_point_and_primitive(query);
Point closest_point = pp.first;
Polyhedron::Face_handle f = pp.second; // closest primitive id
std::cout << "closest point: " << closest_point << std::endl;
std::cout << "closest triangle: ( "
<< f->halfedge()->vertex()->point() << " , "
<< f->halfedge()->next()->vertex()->point() << " , "
<< f->halfedge()->next()->next()->vertex()->point()
<< " )" << std::endl;
return EXIT_SUCCESS;
}