CGAL users discussion list

[Andreas Fabri <>]

 wrote:
> Hi, I'm trying to solve this problem and I'm just wondering what is the best 
> way of doing it.
>
> Basically, I've got a set of points describing a shape (They're basically the 
> points of a surface triangulation in 3D). I've computed the normal at each 
> point as the average normal of all the triangles incident to this point. Now 
> I need to compute the 3D Delaunay tethraedisation and select those edges that 
> form an angle with the normal that is less than a certain threshold. I'm 
> using a vertex iterator to visit all the vertices and then I find all the 
> incident cells to that vertex, then I think there should be a way of finding 
> the edges incident to the vertex I'm considering (I know that in this way I'm 
> visiting the same edge more than once, but is the only way I can think about 
> now). Now it comes the problem, how can I associate a vertex with its 
> normal?? My points are saved into a file in the form:
>
> x y z nx ny nz 
>
> where the first three components are the coordinates of the point and the 
> last three are the normal components.
> I guess that the best way of dealing with these would be extending the 
> concept of point and adding somehow the information about the normal to that 
> and acces this using a method like point.get_Normal(). Is this a good 
> approach? In this case which class should I modify?
>
> Thanks very much for your time and help
>
> Angelo T.


Hi,

You should use the Triangulation_vertex_with_info_3

andreas