CGAL users discussion list

[Joe C <>]

Thanks, Peter. I also found that there are two degenerated triangles for my input data. So I guess CGAL's polyhedron_3 still considers this as closed and valid even though it has degeneated cases. I suggest that the two methods : is_close() or is_valid() return false with some error message so the user is aware that the polyhedron with degenerated triangles is not allowed to converted to Nef_polyhedron.

Joe

On Mon, Mar 30, 2009 at 2:51 PM, Peter Hachenberger <> wrote:

Hi Joe,

your model features two empty triangles, i.e., the defining points are colinear. It's the following lines:

3  19 17 18
3  30 32 31

I attached a Nef file that is consistent, but you probably want to fix your off-file, too.

Peter
 

-----Joe C <> wrote: -----

To:
From: Joe C <>
Date: 03/28/2009 12:02AM
Subject: [cgal-discuss] Conversion from Polyhedron_3 to Nef_polyhedron_3 failed

Hi,

I was converting a polyhedron (see attached Polyhedron.off) to Nef_polyhedron_3, but it failed. I checked my polyhedron, it is closed and valid. The kernel used is Exact_predicates_exact_constructions_kernel. Does anyone have idea why the conversion failed? Is there any way to catch the failure and avoid crashing the program?

Thanks.
Joe

[attachment "Polyhedron.off" removed by Peter Hachenberger]