Surface_mesh_segmentation/sdf_values_example.cpp

#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polyhedron_3.h>
 
#include <CGAL/mesh_segmentation.h>
#include <CGAL/property_map.h>
 
#include <iostream>
#include <fstream>
 
typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
typedef CGAL::Polyhedron_3<Kernel> Polyhedron;
typedef boost::graph_traits<Polyhedron>::face_descriptor face_descriptor;
 
int main()
{
  // create and read Polyhedron
  Polyhedron mesh;
  std::ifstream input(CGAL::data_file_path("meshes/cactus.off"));
  if ( !input || !(input >> mesh) || mesh.empty() || ( !CGAL::is_triangle_mesh(mesh)) )
  {
    std::cerr << "Input is not a triangle mesh" << std::endl;
    return EXIT_FAILURE;
  }
 
  // create a property-map
  typedef std::map<face_descriptor, double> Face_double_map;
  Face_double_map internal_map;
  boost::associative_property_map<Face_double_map> sdf_property_map(internal_map);
 
  // compute SDF values
  std::pair<double, double> min_max_sdf = CGAL::sdf_values(mesh, sdf_property_map);
 
  // It is possible to compute the raw SDF values and post-process them using
  // the following lines:
  // const std::size_t number_of_rays = 25;  // cast 25 rays per face
  // const double cone_angle = 2.0 / 3.0 * CGAL_PI; // set cone opening-angle
  // CGAL::sdf_values(mesh, sdf_property_map, cone_angle, number_of_rays, false);
  // std::pair<double, double> min_max_sdf =
  //  CGAL::sdf_values_postprocessing(mesh, sdf_property_map);
 
  // print minimum & maximum SDF values
  std::cout << "minimum SDF: " << min_max_sdf.first
            << " maximum SDF: " << min_max_sdf.second << std::endl;
 
  // print SDF values
  for(face_descriptor f : faces(mesh))
      std::cout << sdf_property_map[f] << " ";
 
  std::cout << std::endl;
  return EXIT_SUCCESS;
}