CGAL users discussion list

[Chris Hamilton <>]

Previously, I've used the GNU triangulated surface library (libgts), but
I've been having precision issues with that, and am now trying to work
with CGAL.  I'm trying to compute the intersection between two closed
and bounded polyhedra.

I'm using Nef_polyhedron_3 with the
Exact_predicates_exact_constructions_kernel.  The polyhedra are being
laoded as .off files through the Polyhedron_3 object, converted to
Nef_polyhedron_3 objects, and the intersection computed.  Afterwards,
the result is converted back to a Polyhedron_3, and output as an .off file.

All is largely well, except sometimes the process fails with the
following message:

 sorry, this triangulation does not deal with
 intersecting constraints

This error occurs during conversion back to Polyhedron_3.  What exactly
does this error mean?  Is there a way I can get the results out as an
.off file?

And on a slightly related question: is there a way to compute the 3d
volume of a closed polyhedron in CGAL?  Either via the Nef_polyhedron_3
data-structure, or the Polyhedron_3, as I'd always be dealing with
closed meshes.

Regards,

Chris