CGAL users discussion list

[Andreas Fabri <>]

Laurent Le Guillou wrote:
> Hello,
>
> With CGAL, is there a way to enumerate (with an iterator
> or something) the neighboors of a vertex : for instance all the
> first neighboors ("order 1" neighboors), the second neighboors
> (neighboor of a neighboor, "order 2" neighboors), the third
> neighboors ("order 3"), and so on, but without enumerating the same
> vertex twice. I am a physicist, without a very deep knowledge of
> graph-related mathematics; I searched in graph-literature but did
> not found any simple algorithm. I need something quite fast as I
> want to select all the neighboors of a given vertex of "order" less
> than a fixed k, and I need to do this for all vertices, in order
> to compute local physical properties (a "local plane" and other
> mechanical properties).

Note that the code I posted does it for one vertex
and exhaustively.
So you have to run it for each vertex and have a
distance recorder that stops when k is reached.

andreas

> Thanks a lot if someone could give me a hint on how to do this
> in an efficient way (I may of course walk across the whole
> polyhedron data structure several times, but my polyhedrons
> have tens of thousands points...).
>
> Cheers,
>
> Laurent
>
> -----------------------------------------------------------------------
>   Laurent LE GUILLOU                      Tel +33 1 44 27 39 93
>   
>
>                       Fax +33 1 44 27 46 38
>   
>
>               GSM +33 6 20 05 75 22
>
>   LPNHE - Université Paris 6
>   Bureau 412 - Tour 33 RdC
>   Campus de Jussieu
>   4 place Jussieu
>   75252 Paris Cedex 05