CGAL 5.6 - 3D Mesh Generation
Mesh_3/mesh_implicit_sphere_variable_size.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/Labeled_mesh_domain_3.h>
#include <CGAL/make_mesh_3.h>
// Domain
typedef K::FT FT;
typedef K::Point_3 Point;
typedef FT (Function)(const Point&);
typedef CGAL::Labeled_mesh_domain_3<K> Mesh_domain;
#ifdef CGAL_CONCURRENT_MESH_3
typedef CGAL::Parallel_tag Concurrency_tag;
#else
typedef CGAL::Sequential_tag Concurrency_tag;
#endif
// Triangulation
// Criteria
typedef CGAL::Mesh_criteria_3<Tr> Mesh_criteria;
// Sizing field
struct Spherical_sizing_field
{
typedef ::FT FT;
typedef Point Point_3;
typedef Mesh_domain::Index Index;
FT operator()(const Point_3& p, const int, const Index&) const
{
FT sq_d_to_origin = CGAL::squared_distance(p, Point(CGAL::ORIGIN));
return CGAL::abs( CGAL::sqrt(sq_d_to_origin)-0.5 ) / 5. + 0.025;
}
};
namespace params = CGAL::parameters;
// Function
FT sphere_function (const Point& p)
{ return CGAL::squared_distance(p, Point(CGAL::ORIGIN))-1; }
int main()
{
Mesh_domain domain = Mesh_domain::create_implicit_mesh_domain
(sphere_function, K::Sphere_3(CGAL::ORIGIN, K::FT(2))
);
// Mesh criteria
Spherical_sizing_field size;
Mesh_criteria criteria(params::facet_angle(30).facet_size(0.1).facet_distance(0.025).
cell_radius_edge_ratio(2).cell_size(size));
// Mesh generation
C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria, params::no_exude().no_perturb());
// Output
std::ofstream medit_file("out.mesh");
CGAL::IO::write_MEDIT(medit_file, c3t3);
medit_file.close();
return 0;
}