CGAL 5.2.2 - Point Set Processing
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/vcm_estimate_edges.h>
#include <CGAL/property_map.h>
#include <CGAL/IO/read_off_points.h>
#include <utility> // defines std::pair
#include <vector>
#include <fstream>
// Types
typedef Kernel::Point_3 Point;
typedef Kernel::Vector_3 Vector;
// Point with normal vector stored in a std::pair.
typedef std::pair<Point, Vector> PointVectorPair;
typedef std::vector<PointVectorPair> PointList;
typedef std::array<double,6> Covariance;
int main (int , char**) {
// Reads a .xyz point set file in points[].
std::list<PointVectorPair> points;
std::ifstream stream("data/");
if (!stream ||
std::cerr << "Error: cannot read file data/" << std::endl;
// Estimates covariance matrices per points.
double R = 0.2,
r = 0.1;
std::vector<Covariance> cov;
CGAL::compute_vcm(points, cov, R, r,
CGAL::parameters::point_map (point_map).geom_traits (Kernel()));
// Find the points on the edges.
// Note that this step is not expensive and can be done several time to get better results
double threshold = 0.16;
std::ofstream output("");
int i = 0;
for(const PointVectorPair& p : points)
if (CGAL::vcm_is_on_feature_edge(cov[i], threshold))
output << p.first << "\n";
return 0;