\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.14 - Triangulated Surface Mesh Approximation
Surface_mesh_approximation/vsa_class_interface_example.cpp
#include <iostream>
#include <fstream>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/Variational_shape_approximation.h>
typedef boost::property_map<Mesh, boost::vertex_point_t>::type Vertex_point_map;
// L21 error metric
typedef Mesh_approximation::Error_metric L21_metric;
int main()
{
// reads input surface triangle mesh
Mesh mesh;
std::ifstream file("data/bear.off");
if (!file || !(file >> mesh) || !CGAL::is_triangle_mesh(mesh)) {
std::cerr << "Invalid off file." << std::endl;
return EXIT_FAILURE;
}
Vertex_point_map vpmap = get(boost::vertex_point, const_cast<Mesh &>(mesh));
// error metric and fitting function
L21_metric error_metric(mesh, vpmap);
// creates VSA algorithm instance
Mesh_approximation approx(mesh, vpmap, error_metric);
// seeds 100 random proxies
approx.initialize_seeds(CGAL::parameters::seeding_method(VSA::RANDOM)
.max_number_of_proxies(100));
// runs 30 iterations
approx.run(30);
// adds 3 proxies to the one with the maximum fitting error,
// running 5 iterations between each addition
approx.add_to_furthest_proxies(3, 5);
// runs 10 iterations
approx.run(10);
// teleports 2 proxies to tunnel out of local minima,
// running 5 iterations between each teleport
approx.teleport_proxies(2, 5);
// runs 10 iterations
approx.run(10);
// extract approximated mesh with default parameters
approx.extract_mesh(CGAL::parameters::all_default());
// get approximated triangle soup
std::vector<Kernel::Point_3> anchors;
std::vector<CGAL::cpp11::array<std::size_t, 3> > triangles;
approx.output(CGAL::parameters::anchors(std::back_inserter(anchors)).
triangles(std::back_inserter(triangles)));
return EXIT_SUCCESS;
}