CGAL users discussion list

[Monique Teillaud <>]

Le 02/02/14 19:27, Marc Glisse a écrit :
> On Sun, 2 Feb 2014, jiju peethambaran wrote:
>
> > Will something like storing circumradius in the tetrahedra in the
> > cellbase
> > work? Can I do that? or Can you suggest an alternative way of doing this?
> > All I want here is to order the tetrahedra in terms of their
> > circumradius...
>
> Alpha_shape_3 already has that, I'm just not sure what the best way is
> to access this information (use filtration() and ignore the simplices of
> lower dimension?). Note that to compute the circumradius, computing the
> circumcenter is certainly not optimal, see Compute_squared_radius_3.

If you want to order all tetrahedra, use Finite_cells_iterator instead 
of writing your own loops.

Note also that Compute_squared_radius_3 operates on points, so, you can 
avoid to construct Tetrahedron_3 objects.

If you want to cache the circumradius to avoid recomputing it several 
times on the same cell, you can use Triangulation_cell_base_with_info_3.
You can also probably take inspiration from the code of 
Triangulation_cell_base_with_circumcenter_3, which allows to cache the 
circumcenter, but not the circumradius.

--
Monique Teillaud
http://www.inria.fr/sophia/members/Monique.Teillaud/
INRIA Sophia Antipolis - Méditerranée
Institut National de Recherche en Informatique et Automatique