\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)

CGAL 4.8 - Triangulated Surface Mesh Simplification

All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Groups Pages
Surface_mesh_simplification/edge_collapse_OpenMesh.cpp
#include <iostream>
#include <fstream>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <OpenMesh/Core/IO/MeshIO.hh>
#include <OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>
#include <CGAL/boost/graph/graph_traits_PolyMesh_ArrayKernelT.h>
// Simplification function
#include <CGAL/Surface_mesh_simplification/edge_collapse.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Count_stop_predicate.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Edge_length_cost.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Midpoint_placement.h>
typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef OpenMesh::PolyMesh_ArrayKernelT</* MyTraits*/> Surface_mesh;
typedef boost::graph_traits<Surface_mesh>::edge_descriptor edge_descriptor;
typedef boost::graph_traits<Surface_mesh>::edge_iterator edge_iterator;
class Constrained_edge_map
{
public:
typedef boost::read_write_property_map_tag category;
typedef bool value_type;
typedef bool reference;
typedef edge_descriptor key_type;
Constrained_edge_map(Surface_mesh& sm)
: sm_(sm)
{
sm_.add_property(constraint);
}
inline friend reference get(const Constrained_edge_map& em, key_type e)
{
bool b = em.sm_.property(em.constraint,em.sm_.edge_handle(e.idx()));
return b;
}
inline friend void put(const Constrained_edge_map& em, key_type e, value_type b)
{
em.sm_.property(em.constraint,em.sm_.edge_handle(e.idx())) = b;
}
private:
Surface_mesh& sm_;
OpenMesh::EPropHandleT<bool> constraint;
};
namespace SMS = CGAL::Surface_mesh_simplification ;
int main( int argc, char** argv )
{
Surface_mesh surface_mesh;
Constrained_edge_map constraints_map(surface_mesh);
if (argc==2)
OpenMesh::IO::read_mesh(surface_mesh, argv[1]);
else
OpenMesh::IO::read_mesh(surface_mesh, "cube.off");
// For the pupose of the example we mark 10 edges as constrained edges
edge_iterator b,e;
int count=0;
for(boost::tie(b,e) = edges(surface_mesh); b!= e; ++b){
put(constraints_map,*b,(count++ <100));
}
// This is a stop predicate (defines when the algorithm terminates).
// In this example, the simplification stops when the number of undirected edges
// left in the surface mesh drops below the specified number (1000)
SMS::Count_stop_predicate<Surface_mesh> stop(0);
// This the actual call to the simplification algorithm.
// The surface mesh and stop conditions are mandatory arguments.
int r = SMS::edge_collapse
(surface_mesh
,stop
,CGAL::parameters::halfedge_index_map (get(CGAL::halfedge_index ,surface_mesh))
.vertex_point_map(get(boost::vertex_point, surface_mesh))
.edge_is_constrained_map(constraints_map)
);
surface_mesh.garbage_collection();
std::cout << "\nFinished...\n" << r << " edges removed.\n"
<< num_edges(surface_mesh) << " final edges.\n" ;
OpenMesh::IO::write_mesh(surface_mesh, "out.off");
return 0 ;
}
// EOF //