CGAL users discussion list

[Jane Tournois <>]

In the helpers, the function

  Vertex_handle move_point(const Vertex_handle& old_vertex,
                           const Point_3& new_position,
                           Outdated_cell_set& outdated_cells_set,
                           Moving_vertices_set& moving_vertices) const;

does exactly what you need.

The `outdated_cells_set` contains the newly created cells. They are 
called "outdated" here because their inside/outside status is not valid 
anymore.

Le 09/09/2016 à 00:24, Brown, James 2 a écrit :
> Thanks, C3T3_helpers.h gives some insight.
>
> > 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.
> Removal makes sense to me; removed cells are the union of the incident cells 
> of the old vertex along with the conflict cells of the new vertex in the old 
> triangulation.
> New cells are not so clear to me, how do I get the cells of the filled cavity?

They are the cells that are incident to the boundary facets of the cavity.

> The helpers have outdated cells, which are the conflict zone of the old point 
> in the new triangulation, is this the cavity triangulation? If this is the 
> case then would the new cells just be the union of the outdated cells and the 
> incident cells of the new vertex?

here is the process:
- collect the incident cells to v
- remove v
- triangulate the cavity --> triangulation T1
- collect cells in conflict with the insertion of newpoint : T2
- insert newpoint
- collect incident cells to new vertex : T3

the newly created cells after removal + insertion is T1-T2+T3.

Jane.

> Thanks,
> James

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