CGAL users discussion list

["Laurent Rineau (GeometryFactory)" <>]

On vendredi 10 juin 2011 23:20:31 Michel Audette wrote:
> Hi Laurent,
> 
> I'm seeing the following error, with a number of different choices for mesh
> size...
> *
> terminate called after throwing an instance of 'CGAL::Assertion_exception'
>  what():  CGAL ERROR: assertion violation!
> Expr: sq_d > 0
> File: /usr/local/include/CGAL/Mesh_3/Protect_edges_sizing_field.h
> Line: 416
> Aborted
> *
> I've been using the following code... See below. So far, I'm trying to get
> a result with constant tet size, even though the surface mesh size has
> edges varying between about 10 and 40mm.
> 
> Is this a bug related to the new boundary faithfulness implementation or a
> consequence of a mismatched size objective?

The set of polylines that you specify with domain.add_features(...) must be a 
graph. The vertices of this graph are the endpoints of the polylines (not all 
points, just the two endpoints of each polyline), and the edges of this graph 
are the polylines. The polylines must not intersect but at their endpoints.

I had a look at your code, and I saw that, as set of feature curves, you 
entered only one polyline with all vertices of the input polyhedron, in the 
order of the vertices iterator. Depending on your polyhedron, that polyline 
probably intersects itself.

-- 
Laurent Rineau, PhD
R&D Engineer at GeometryFactory           http://www.geometryfactory.com/
Release Manager of the CGAL Project       http://www.cgal.org/