[Gmsh] R: Integer flag to .msh elements

Alessandro Vicini a.vicini at alta-space.com
Thu Oct 24 13:38:59 CEST 2013

Hullo everybody,

the problem is (as far as I know), that when you assign a surface to a
physical group, you don't have control on the number of the group, which is
automatically assigned by Gmesh. If I understand what Umberto is saying
(which is the same thing that would be useful in my case), it would be nice
to have the possibility of explicitly assigning these integer flags to
surfaces (or groups of surfaces), in order to specify boundary conditions.



-----Messaggio originale-----
Da: gmsh-bounces at ace20.montefiore.ulg.ac.be
[mailto:gmsh-bounces at ace20.montefiore.ulg.ac.be] Per conto di David Colignon
Inviato: giovedì 24 ottobre 2013 13.02
A: Umberto Iemma; gmsh at geuz.org
Oggetto: Re: [Gmsh] Integer flag to .msh elements

On 24/10/13 11:57, Umberto Iemma wrote:
> First, I'd like to thank the authors for the wonderful work they are doing
> Gmsh is one of the most useful free technical tools ever!
> Thanks!
> After this, I have a question.
> It is possible to include in the .msh file a integer flag to each element
> I need this to specify particular physical properties of the boundary.

Hi Umberto,

you should use Physical groups for that purpose, see

"Groups of elementary geometrical entities can also be defined and are
called “physical” entities. 
These physical entities cannot be modified by geometry commands: their only
purpose is to assemble elementary entities into larger groups, possibly
modifying their orientation, so that they can be referred to by the mesh
module as single entities. As is the case with elementary entities, each
physical point, physical line, physical surface or physical volume must be
assigned a unique identification number. "

and tutorial t1.geo, http://geuz.org/gmsh/doc/texinfo/gmsh.html#t1_002egeo



David Colignon, Ph.D.
Collaborateur Logistique du F.R.S.-FNRS
CÉCI - Consortium des Équipements de Calcul Intensif ACE - Applied &
Computational Electromagnetics Université de Liège Sart-Tilman B28 10,
Grande Traverse
4000 Liège - BELGIQUE
Tél: +32 (0)4 366 37 32
WWW:    http://www.ceci-hpc.be/

> I'm the coordinator of the open-source project AcouSTO 
> http://acousto.sourceforge.net, a tool for acoustic simulation. I'm 
> going to release soon version 1.6 including the possibility to read Gmsh
> Everything is working fine and the release candidate could be issued 
> now, but this additional possibility would broaden significantly the 
> field of application.
> Thanks in advance,
> Umberto
> *****************************************************************
>     Prof. Umberto IEMMA
>     Associate Professor of Aerospace Structures and Design
>     Dip. di Ingegneria - Universita' Roma Tre
>     via Vito Volterra 62, 00146 Roma
>     tel. +39-0657333274 fax  +39-065593732
>     www   : http://acousto.sourceforge.net
> *****************************************************************
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh

gmsh mailing list
gmsh at geuz.org

More information about the gmsh mailing list