CGAL 5.1.2 - Polygon Mesh Processing
Polygon_mesh_processing/compute_normals_example_Polyhedron.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Polyhedron_3.h>
#include <CGAL/Polygon_mesh_processing/compute_normal.h>
#include <boost/property_map/property_map.hpp>
#include <map>
// #include <CGAL/Unique_hash_map.h>
// #include <boost/unordered_map.hpp>
#include <iostream>
#include <fstream>
typedef K::Point_3 Point;
typedef K::Vector_3 Vector;
typedef CGAL::Polyhedron_3<K> Polyhedron;
typedef boost::graph_traits<Polyhedron>::vertex_descriptor vertex_descriptor;
typedef boost::graph_traits<Polyhedron>::face_descriptor face_descriptor;
int main(int argc, char* argv[])
{
const char* filename = (argc > 1) ? argv[1] : "data/eight.off";
std::ifstream input(filename);
Polyhedron mesh;
if (!input || !(input >> mesh) || mesh.is_empty()) {
std::cerr << "Not a valid off file." << std::endl;
return 1;
}
std::map<face_descriptor,Vector> fnormals;
std::map<vertex_descriptor,Vector> vnormals;
// Instead of std::map you may use std::unordered_map, boost::unordered_map
// or CGAL::Unique_hash_map
// CGAL::Unique_hash_map<face_descriptor,Vector> fnormals;
// boost::unordered_map<vertex_descriptor,Vector> vnormals;
boost::make_assoc_property_map(vnormals),
boost::make_assoc_property_map(fnormals));
std::cout << "Face normals :" << std::endl;
for(face_descriptor fd: faces(mesh)){
std::cout << fnormals[fd] << std::endl;
}
std::cout << "Vertex normals :" << std::endl;
for(vertex_descriptor vd: vertices(mesh)){
std::cout << vnormals[vd] << std::endl;
}
return 0;
}