CGAL 5.4.3 - 3D Surface Mesh Generation
Surface_mesher/mesh_an_implicit_function.cpp
#include <CGAL/Surface_mesh_default_triangulation_3.h>
#include <CGAL/Complex_2_in_triangulation_3.h>
#include <CGAL/make_surface_mesh.h>
#include <CGAL/Implicit_surface_3.h>
#include <CGAL/IO/facets_in_complex_2_to_triangle_mesh.h>
#include <CGAL/Surface_mesh.h>
#include <fstream>
// default triangulation for Surface_mesher
// c2t3
typedef CGAL::Complex_2_in_triangulation_3<Tr> C2t3;
typedef Tr::Geom_traits GT;
typedef GT::Sphere_3 Sphere_3;
typedef GT::Point_3 Point_3;
typedef GT::FT FT;
typedef FT (*Function)(Point_3);
typedef CGAL::Surface_mesh<Point_3> Surface_mesh;
FT sphere_function (Point_3 p) {
const FT x2=p.x()*p.x(), y2=p.y()*p.y(), z2=p.z()*p.z();
return x2+y2+z2-1;
}
int main() {
Tr tr; // 3D-Delaunay triangulation
C2t3 c2t3 (tr); // 2D-complex in 3D-Delaunay triangulation
// defining the surface
Surface_3 surface(sphere_function, // pointer to function
Sphere_3(CGAL::ORIGIN, 2.)); // bounding sphere
// Note that "2." above is the *squared* radius of the bounding sphere!
// defining meshing criteria
CGAL::Surface_mesh_default_criteria_3<Tr> criteria(30., // angular bound
0.1, // radius bound
0.1); // distance bound
// meshing surface
CGAL::make_surface_mesh(c2t3, surface, criteria, CGAL::Non_manifold_tag());
Surface_mesh sm;
std::ofstream out("sphere.off");
out << sm << std::endl;
std::cout << "Final number of points: " << tr.number_of_vertices() << "\n";
}