## CGAL::Nef_polyhedron_3<Traits>::SFace

### Definition

Figure and figure illustrate the incidences of an sface. An sface is described by its boundaries. An entry item to each boundary cycle can be accessed using the iterator range (sface_cycles_begin()/sface_cycles_end()). Additionally, Nef_polyhedron_S2 provides the macro CGAL_forall_sface_cylces_of. The iterators are of type SFace_cycle_const_iterator and represent either a shalfedge, a shalfloop, or a svertex.

#include <CGAL/Nef_polyhedron_3.h>

### Types

The following types are the same as in Nef_polyhedron_3<Traits>.

Nef_polyhedron_3<Traits>::SFace::Mark
| type of mark.
Nef_polyhedron_3<Traits>::SFace::Object_list
| list of Object handles.
Nef_polyhedron_3<Traits>::SFace::Vertex_const_handle
| const handle to Vertex.
Nef_polyhedron_3<Traits>::SFace::Volume_const_handle
| const handle to Volume.
Nef_polyhedron_3<Traits>::SFace::SFace_const_handle
| const handle to SFace.
Nef_polyhedron_3<Traits>::SFace::SFace_cycle_const_iterator
| const iterator over the entries to all sface cycles of a sface.

### Creation

There is no need for a user to create a SFace explicitly. The class Nef_polyhedron_3<Traits> manages the needed sfaces internally.

### Operations

Mark | sf.mark () | the mark of sf .
Vertex_const_handle
| sf.center_vertex ()
|  | the center vertex of the sphere map sf belongs to.
Volume_const_handle
| sf.volume () | the volume that corresponds to sf in the 3D incidence structure.
SFace_cycle_const_iterator
| sf.sface_cycle_begin ()
|  | iterator over the entries to all sface cycles of sf .
SFace_cycle_const_iterator
| sf.sface_cycle_end ()
|  | past-the-end iterator.

### See Also

CGAL::Nef_polyhedron_3<Traits>::Vertex
CGAL::Nef_polyhedron_3<Traits>::Volume