CGAL users discussion list

[Mariette Yvinec <>]

It might work...but some of your vertices will be now outside or inside
the surface. Therefore you will have some vertices
that are not on the surface
and it may happen that the restricted Delaunay triangulation to the zero level set
(which is the surface mesh)
include facets incident to vertices that are not on the zero level set.
Such a facet is considered as bad and refined in Mesh_3.
In the surface mesher,  because every vertex is supposed to be on the surface to be meshed
there is no test to ensure that restricted Delaunay facet
have their vertices on the surface....

In summary, there is a risk that you end up
with a surface mesh with vertices that are not
on the zero-level set.

Mariette

Amir Vaxman wrote:

What will happen if I use the original un-updated surface? Is the refinement capable of handling the change without erasing? (suppose that the change is not very massive).

 

From: Mariette Yvinec []
Sent: Monday, September 14, 2009 12:35 PM
To:
Subject: Re: [cgal-discuss] Online Mesh Generation

 

The following might work :

Delete from the C2T3::triangulation the vertices which are no longer
on the zero level set
Reinitialize a C2T3 with the updated triangulation
and call  again make_surface_mesh using :
- the C2T3
- the modified function
- an initial number of points equals to 0


Amir Vaxman wrote:

I am working with implicit functions to which I make a zero-level surface. I want  to make these functions updatable – that is, I create a surface, and then I change the function in some area of space, and I want to re-create the surface. The change is relatively local, so it should affect only a (known) part of the mesh. Is there a possibility to maybe “erase” part of the surface and update it with the new function, using CGAL’s mesh generation?

 

Amir.

-- 

Mariette Yvinec

Geometrica project team

INRIA  Sophia-Antipolis  

-- 
Mariette Yvinec
Geometrica project team
INRIA  Sophia-Antipolis