CGAL users discussion list

[Jane Tournois <>]

Le 01/09/2016 à 11:48, Laurent Rineau (CGAL/GeometryFactory) a écrit :

> Le Wednesday, August 31, 2016 3:50:41 PM CEST Brown, James 2 a écrit :
> > I need to find changed cells (removed and new) for moved vertices. The
> > movement I have is fairly small but because some tetrahedra are very 'thin'
> > sometimes the points cross a face causing the tetrahedron to be in an
> > opposite orientation which would require the neighboring cells to be
> > retriangulated.
> When the Mesh Optimizers (from CGAL Mesh_3) do move vertices, the code needs
> to have the same knowledge.
>
> You may find what you need in the big collection of helper functions in <CGAL/
> Mesh_3/C3T3_helpers.h>.
That's right.

Moving a vertex implies :
- removing the old vertex : the new cells are the ones that triangulate 
the cavity formed by removing it
- inserting the position to a new vertex : the new cells are the cells 
incident to the new vertex

These groups of cells are not the same, and a union of them has to be done.
C3T3_helpers.h contains everything you need.

Best,

--
Jane Tournois, PhD
R&D Engineer at GeometryFactory
http://www.geometryfactory.com/