CGAL users discussion list

["Jens K. Becker" <>]

Hi all,

I have a problem with the join_facets-function for polyhedra. I try to join
facets in a polyhedron. Sometimes it works and sometimes not. Sometimes, the
call to join_facet leaves the polyhedron with an "antenna" and then 
later calls
to join_facet obviously dont work (precondition error).
If I use is_valid(true) (I can post the output of one but it is long), 
it tells
me that
...
...
both incident facets are equal.
counting halfedges failed.
end of CGAL::Polyhedron_3<...>::is_valid(): structure is NOT VALID.

and then the next call to join_facets runs forever (in the while-loop 
in HalfedgeDS_decorator.h, line 271 to 275).
If I dont use the is_valid, it stops with a precondition error.

I am using

#typedef CGAL::Exact_predicates_inexact_constructions_kernel K;

as a kernel.

Any ideas? Why does join_facets only sometimes produces these antennas and not
always? And why does it do that at all (in all cases, the polyhedron had lots
of facets (it was not only a tetrahedron))?


Any help is greatly appreciated,

Jens

--
Dr. J.K. Becker
University of Tuebingen - Institute for Geoscience
Sigwartst. 10 - 72076 Tuebingen (Germany)
Tel.: ++49 7071 29 73139   Fax: +49 7071 5059
web: http://www.jkbecker.de