\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.12.2 - Triangulated Surface Mesh Simplification
Surface_mesh_simplification/edge_collapse_bounded_normal_change.cpp
#include <iostream>
#include <fstream>
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Polyhedron_3.h>
#include <CGAL/IO/Polyhedron_iostream.h>
#include <CGAL/boost/graph/graph_traits_Polyhedron_3.h>
// Simplification function
#include <CGAL/Surface_mesh_simplification/edge_collapse.h>
// Stop-condition policy
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Count_stop_predicate.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/LindstromTurk_cost.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/LindstromTurk_placement.h>
#include <CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Bounded_normal_change_placement.h>
typedef CGAL::Polyhedron_3<Kernel> Surface_mesh;
int main( int argc, char** argv )
{
Surface_mesh surface_mesh;
std::ifstream is(argc > 1 ? argv[1] : "data/fold.off") ; is >> surface_mesh ;
// 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(num_halfedges(surface_mesh)/2 - 1);
typedef SMS::Bounded_normal_change_placement<SMS::LindstromTurk_placement<Surface_mesh> > Placement;
// This the actual call to the simplification algorithm.
// The surface mesh and stop conditions are mandatory arguments.
// The index maps are needed because the vertices and edges
// of this surface mesh lack an "id()" field.
SMS::edge_collapse( surface_mesh,
stop,
CGAL::parameters::vertex_index_map(get(CGAL::vertex_external_index,surface_mesh))
.halfedge_index_map (get(CGAL::halfedge_external_index ,surface_mesh))
.get_cost (SMS::LindstromTurk_cost<Surface_mesh>())
.get_placement(Placement())
);
std::ofstream os( argc > 2 ? argv[2] : "out.off" ) ; os << surface_mesh ;
return 0 ;
}