CGAL users discussion list

[Mateus Bellomo <>]

I was expecting cgal to update to me the edges of vertex v accordingly with it's new position but I think this is not going to happen. In fact I managed a way to do what I'm wanting: before I remove the edges incident to v, I'm storing the indices of adjacent faces in a vector and when inserting the new edges I'm recovering the indices respectively.

That way I'm sure the topology is still consistent.

2016-02-03 20:02 GMT-02:00 Efi Fogel <>:

You can change the coordinates of the point of a vertex directly, but if the change results with topological changes you end up with an inconsistent state.
It's unclear what exactly you are trying to do. That is, how do you want to deal with topological changes?

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On Wed, Feb 3, 2016 at 10:13 PM, Mateus Bellomo <> wrote:

Hello all,

I have a quadrilateral grid as an Arrangement_2. I'm making some operations in it as moving some vertices with degree 4. To make this operations I'm removing the four edges incident to a vertex v, change the v position and putting back the edges in v with its neighbours. After this operations I want to iterate over the arrangement faces in a certain order, as I defined in the beginning extending DCEL faces and attributing an index. I noticed that my face indices are becoming 0 after the moving operations and I think it's right since I'm merging 4 faces into 1 and then splitting this face in another 4.

I'm wondering if there is a way to move a vertex with degree 4 without changing the four faces adjacent to it.

Thanks

Mateus