CGAL users discussion list

[Noel Warren <>]

I have a function that splits Nefs into smaller nefs from the shells of the volumes.  I am doing it using an undocumented Nef constructor.  In the majority of cases it works a charm but ocasionally it fails.  I have attatched a nef that fails (infact it only has one volume so should return an Array of length 1 containing a Nef) when trying to split.

Here is a code snippet

vector<Nef_polyhedron_3> nefs;

Nef_polyhedron_3::Volume_const_iterator vi = ++N.volumes_begin();

Nef_polyhedron_3::Shell_entry_const_iterator si;

CGAL_forall_volumes(vi,N) {

if(vi->mark()) {

Nef_polyhedron_3::Shell_entry_const_iterator si;

CGAL_forall_shells_of(si, vi) {

Nef_polyhedron_3::SFace_const_handle sfch(si);

Nef_polyhedron_3 O(N,sfch);

nefs.push_back(O);

}  

}

}

Here is the error...

CGAL ERROR: assertion violation! (RuntimeError)

Expr: itl != it->second.end()

File: /usr/local/include/CGAL/Nef_3/SNC_external_structure.h

Line: 1102

If I shouldn't be using this Nef constructor, how should I go about "splitting" a nef into smaller ones.  Thanks in advance for your time.

Attachment: e_split.nef
Description: Binary data