CGAL 5.4.4 - Triangulated Surface Mesh Simplification
Surface_mesh_simplification/edge_collapse_garland_heckbert.cpp
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/Surface_mesh_simplification/edge_collapse.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Count_ratio_stop_predicate.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Bounded_normal_change_placement.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/GarlandHeckbert_policies.h>
#include <chrono>
#include <iostream>
#include <fstream>
#include <vector>
typedef Kernel::FT FT;
typedef Kernel::Point_3 Point_3;
typedef CGAL::Surface_mesh<Point_3> Surface_mesh;
int main(int argc, char** argv)
{
Surface_mesh surface_mesh;
const std::string filename = (argc > 1) ? argv[1] : CGAL::data_file_path("meshes/cube-meshed.off");
std::ifstream is(filename);
if(!is || !(is >> surface_mesh))
{
std::cerr << "Failed to read input mesh: " << filename << std::endl;
return EXIT_FAILURE;
}
if(!CGAL::is_triangle_mesh(surface_mesh))
{
std::cerr << "Input geometry is not triangulated." << std::endl;
return EXIT_FAILURE;
}
std::cout << "Input mesh has " << num_vertices(surface_mesh) << " nv "
<< num_edges(surface_mesh) << " ne "
<< num_faces(surface_mesh) << " nf" << std::endl;
std::chrono::steady_clock::time_point start_time = std::chrono::steady_clock::now();
const double ratio = (argc > 2) ? std::stod(argv[2]) : 0.2;
SMS::Count_ratio_stop_predicate<Surface_mesh> stop(ratio);
// Garland&Heckbert simplification policies
typedef typename SMS::GarlandHeckbert_policies<Surface_mesh, Kernel> GH_policies;
typedef typename GH_policies::Get_cost GH_cost;
typedef typename GH_policies::Get_placement GH_placement;
typedef SMS::Bounded_normal_change_placement<GH_placement> Bounded_GH_placement;
GH_policies gh_policies(surface_mesh);
const GH_cost& gh_cost = gh_policies.get_cost();
const GH_placement& gh_placement = gh_policies.get_placement();
Bounded_GH_placement placement(gh_placement);
std::cout << "Collapsing edges of mesh: " << filename << ", aiming for " << 100 * ratio << "% of the input edges..." << std::endl;
int r = SMS::edge_collapse(surface_mesh, stop,
CGAL::parameters::get_cost(gh_cost)
.get_placement(placement));
std::chrono::steady_clock::time_point end_time = std::chrono::steady_clock::now();
std::cout << "Time elapsed: "
<< std::chrono::duration_cast<std::chrono::milliseconds>(end_time - start_time).count()
<< "ms" << std::endl;
std::cout << "\nFinished!\n" << r << " edges removed.\n" << surface_mesh.number_of_edges() << " final edges.\n";
CGAL::IO::write_polygon_mesh((argc > 3) ? argv[3] : "out.off", surface_mesh, CGAL::parameters::stream_precision(17));
return EXIT_SUCCESS;
}