CGAL::make_surface_mesh

#include <CGAL/make_surface_mesh.h>

Definition

The function make_surface_mesh is a surface mesher, that is a function to build a two dimensional mesh approximating a surface.

The library provides two overloaded version of this function:

template <class SurfaceMeshC2T3, class Surface, class Criteria, class Tag >
void	make_surface_mesh ( SurfaceMeshC2T3& c2t3, Surface surface, Criteria criteria, Tag, int initial_number_of_points = 20)
template <class SurfaceMeshC2T3, class SurfaceMeshTraits, class Criteria, class Tag >
void	make_surface_mesh ( SurfaceMeshC2T3& c2t3, SurfaceMeshTraits::Surface_3 surface, SurfaceMeshTraits traits, Criteria criteria, Tag, int initial_number_of_points = 20)

Parameters

The template parameter Surface stands for the surface type. This type has to be a model of the concept Surface_3.

The knowledge on the surface, required by the surface mesher is encapsulated in a traits class. Actually, the mesher accesses the surface to be meshed through this traits class only. The traits class is required to be a model of the concept SurfaceMeshTraits_3.

In the first version of make_surface_mesh the surface type is a template paramater Surface and the surface mesher traits type is automatically generated form the surface type through the class Surface_mesh_traits_generator_3<Surface>.

The difference between the two overloaded versions of make_surface_mesh can be explained as follows

• In the first overloaded version of of make_surface_mesh, the surface type is given as template paramater (Surface) and the surface to be meshed is passed as parameter to the mesher. In that case the surface mesher traits type is automatically generated form the surface type by an auxiliary class called the Surface_mesh_traits_generator_3.
• In the second overloaded version of make_surface_mesh, the surface mesher traits type is provided by the template parameter SurfaceMeshTraits_3 and the surface type is obtained from this traits type. Both the surface and the traits are passed to the mesher as arguments.

The first overloaded version can be used whenever the surface type either provides a nested type Surface::Surface_mesher_traits_3 that is a model of SurfaceMeshTraits_3 or is a surface type for which a specialization of the traits generator Surface_mesh_traits_generator_3<Surface> is provided. Currently, the library provides partial specializations of Surface_mesher_traits_generator_3<Surface> for implicit surfaces (Implicit_surface_3<Traits, Function> ) and grey level images (Gray_level_image_3<FT, Point> ).

The template parameter Criteria has to be a model of the concept SurfaceMeshCriteria_3. The argument of type Criteria passed to the surface mesher specifies the size and shape requirements on the output surface mesh.

The template parameter Tag is a tag whose type affects the behaviour of the meshing algorithm. The function make_surface_mesh has specialized versions for the following tag types:
- Manifold_tag: the output mesh is guaranteed to be a manifold surface without boundary.
- Manifold_with_boundary_tag: the output mesh is guaranteed to be manifold but may have boundaries.
- Non_manifold_tag: the algorithm relies on the given criteria and guarantees nothing else.

The Delaunay refinement process is started with an initial set of points which is the union of two sets: the set of vertices in the initial triangulation pointed to by the c2t3 argument and a set of points provided by the traits class. The optional parameter initial_number_of_points allows to monitor the number of points in this second set. (This parameter is passed to the operator() of the constructor object Construct_initial_points in the traits class.) The meshing algorithm requires that the initial set of points includes at least one point on each connected components of the surface to be meshed. one.

See Also