CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

You can use a vertex type with id like:
  typedef CGAL::Polyhedron_3<Kernel, CGAL::Polyhedron_items_with_id_3> 
Polyhedron_3;
https://doc.cgal.org/latest/BGL/classCGAL_1_1Polyhedron__items__with__id__3.html
In particular with this type, any face/vertex/face handle has a id() 
field that can be set and access:

vh->id()=33;
std::cout << vh->id() << "\n";

Another option is to use the class Surface_mesh that have descriptor 
being index (not necessarily contiguous if some removal were done and
collect_garbage() has not been called).

https://doc.cgal.org/latest/Surface_mesh/

Sebastien.


On 2/26/19 5:50 AM, Robert Sage wrote:
> Hello,
> We need to convert Polyhedron_3 facet vertices from Vertex_handle to 
> integer ids exactly like I see in:
> https://doc.cgal.org/latest/Polyhedron/Polyhedron_2polyhedron_prog_off_8cpp-example.html
> So we have adapted this code but are observing each std::distance 
> operation runs at O(n) and thus the whole conversion takes a long time 
> for Polyhedron with many facets. Is there a more efficient way?
> Thank you!
> Robert