[Gmsh] FW: FW: Bug in gmsh-2.2.3 / OCC?

Billy Araújo billy at dem.uminho.pt
Tue Jul 22 22:44:35 CEST 2008


Hi,

I found out that some invalid surfaces appear due to the geometry tolerance being too high.
I didn't realize that the geometry tolerance merged points on the same surface rendering the surface invalid. 
Initially I used a high tolerance to sew surfaces together which is a very nice feature to guarantee a continuous mesh.

Regards,

Billy.





-----Mensagem original-----
De: David Colignon [mailto:David.Colignon at ulg.ac.be]
Enviada: ter 22-07-2008 8:13
Para: Billy Araújo
Cc: gmsh at geuz.org
Assunto: Re: [Gmsh] FW:  Bug in gmsh-2.2.3 / OCC?
 



Billy Araújo wrote:
> 
> Hi,
> 
> First, I would like to congratulate you for developing such a great 
> software.
> 
> I tried with version 2.1.0 and the it is able to import with no errors 
> and mesh this surface. This is a surface of a more complex part which I 
> broke down until finding the problematic surface. When I meshed the 
> part, this surface caused a crash of Gmsh and I couldn't retreive the 
> mesh of other surfaces. I would be glad if gmsh presented an error 
> during meshing that surface but still being able to export the mesh of 
> the non-failing surfaces. Then I could correct the mesh using a mesh editor.
> 
> I know STEP is better than IGES for importing in Gmsh. I also tested 
> several "flavours" of IGES coming from Rhino3d and I found one which is 
> almost as good as STEP. 


Hi Billy,

can you tell us which flavor of IGES exported by Rhino is working well ?

Thanks,

Dave

-- 
David Colignon, Ph.D.
Collaborateur Logistique du F.R.S.-FNRS (Equipements de Calcul Intensif)
ACE - Applied & Computational Electromagnetics
Institut Montefiore B28
Université de Liège
4000 Liège - BELGIQUE
Tél: +32 (0)4 366 37 32
Fax: +32 (0)4 366 29 10
WWW:    http://www.montefiore.ulg.ac.be/personnel.php?op=detail&id=898
Agenda: http://www.google.com/calendar/embed?src=david.colignon%40gmail.com

However, I have a part that also produces a
> similiar error during import like:
> 
> Error   : Something wrong in edge loop
> Warning : OCC STL triangulation failed
> 
> using STEP or IGES format with any "flavour". And when I mesh it, Gmsh 
> crashes. Although, as I said I would be more than glad if Gmsh just 
> presented a message of the failing surface and/or not try to mesh these 
> surfaces. This way I could still export the mesh.
> 
> Regards,
> 
> Billy.
> 
> 
> 
> -----Mensagem original-----
> De: Christophe Geuzaine [mailto:cgeuzaine at ulg.ac.be]
> Enviada: seg 21-07-2008 19:23
> Para: Billy Araújo
> Cc: gmsh at geuz.org
> Assunto: Re: [Gmsh] FW:  Bug in gmsh-2.2.3 / OCC?
> 
> Billy Araújo wrote:
>  >
>  > I forgot to say that this happens using the windows version. I tried on
>  > the Linux version and it seems to be working OK.
> 
> Hi Billy - Even on Linux the parametrization of the surface looks weird,
> and the resulting mesh is extremely distorted.
> 
> If possible always try to use STEP files instead of IGES (IGES files do
> not contain the topology, so a geometrical tolerance must be used to
> decide when entities are identical).
> 
>  >
>  > Regards,
>  >
>  > Billy.
>  >
>  >
>  > -----Original Message-----
>  > From: gmsh-bounces at geuz.org on behalf of Billy Araújo
>  > Sent: Thu 7/17/2008 12:35 AM
>  > To: gmsh at geuz.org
>  > Subject: [Gmsh] Bug in gmsh-2.2.3 / OCC?
>  >
>  >
>  > Hi,
>  >
>  >
>  > I send an IGES file in attachment.
>  >
>  > It gives an error in the edge loop when importing.
>  >
>  > Error   : Something wrong in edge loop
>  > Warning : OCC STL triangulation failed
>  >
>  > And when I try to mesh it, Gmsh crashes.
>  >
>  >
>  > Billy.
>  >
>  >
>  > ------------------------------------------------------------------------
>  >
>  > _______________________________________________
>  > gmsh mailing list
>  > gmsh at geuz.org
>  > http://www.geuz.org/mailman/listinfo/gmsh
> 
> 
> --
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.geuz.org/pipermail/gmsh/attachments/20080722/fcb1c1ab/attachment.html>