\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.13.2 - 3D Mesh Generation
Mesh_3/mesh_polyhedral_domain_with_lipschitz_sizing.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Mesh_triangulation_3.h>
#include <CGAL/Mesh_complex_3_in_triangulation_3.h>
#include <CGAL/Mesh_criteria_3.h>
#include <CGAL/Polyhedral_mesh_domain_with_features_3.h>
#include <CGAL/make_mesh_3.h>
#include <CGAL/Mesh_3/experimental/Lipschitz_sizing_polyhedron.h>
//Kernel
typedef K::FT FT;
// Domain
#ifdef CGAL_CONCURRENT_MESH_3
typedef CGAL::Parallel_tag Concurrency_tag;
#else
typedef CGAL::Sequential_tag Concurrency_tag;
#endif
// Triangulation
Tr,Mesh_domain::Corner_index,Mesh_domain::Curve_index> C3t3;
// Criteria
typedef CGAL::Mesh_criteria_3<Tr> Mesh_criteria;
// Sizing field
typedef CGAL::Mesh_3::Lipschitz_sizing<K, Mesh_domain, Mesh_domain::AABB_tree> Lip_sizing;
// To avoid verbose function and named parameters call
using namespace CGAL::parameters;
int main(int argc, char*argv[])
{
const char* fname = (argc>1) ? argv[1] : "data/fandisk.off";
std::ifstream input(fname);
Polyhedron polyhedron;
input >> polyhedron;
if (input.fail()){
std::cerr << "Error: Cannot read file " << fname << std::endl;
return EXIT_FAILURE;
}
if (!CGAL::is_triangle_mesh(polyhedron)){
std::cerr << "Input geometry is not triangulated." << std::endl;
return EXIT_FAILURE;
}
// Create domain
Mesh_domain domain(polyhedron);
// Get sharp features
domain.detect_features();
// Create Lipschitz sizing field
Lip_sizing lip_sizing(domain, &domain.aabb_tree());
FT min_size = 0.02;
lip_sizing.add_parameters_for_subdomain(1, //subdomain id
0.3, //k
min_size,//min_size
0.5); //max_size
// Mesh criteria
Mesh_criteria criteria(edge_size = min_size,
facet_angle = 25,
facet_size = min_size,
facet_distance = 0.005,
cell_radius_edge_ratio = 3,
cell_size = lip_sizing);
// Mesh generation
C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria);
// Output
std::ofstream medit_file("out.mesh");
c3t3.output_to_medit(medit_file);
return EXIT_SUCCESS;
}