[Gmsh] conformal mulitregion meshing from commandline +step file import

[Zenker, Dr. Matthias]

Hi,

the mesh in the picture in the post http://forum.freecadweb.org/viewtopic.php?f=18&t=10846&sid=2d71e90e5bc6cb707fb96796681a84ca&start=10#p103981 looks conformal, but if I open it in gmsh, it looks loke a single body. In the picture in the post http://forum.freecadweb.org/viewtopic.php?f=18&t=10846&sid=2d71e90e5bc6cb707fb96796681a84ca&start=20#p103993 is not conformal at the interface.
By "conformal" I mean that the triangles and nodes on both touching faces are the same. Only then you can have heat or current flow between bodies. If the OCC functions for connecting/sewing faces work only for flat faces as suggested in the thread you cite, they are next to useless since curved faces occur in 3D. It seems that at the moment only Salomé can sew such faces - but AFAIK Salomé uses OCC also, so there must be a way...

Matthias

> -----Ursprüngliche Nachricht-----
> Von: Anan Im [mailto:ananim343297 at yandex.com]
> Gesendet: Montag, 26. Oktober 2015 18:39
> An: gmsh at geuz.org
> Betreff: Re: [Gmsh] conformal mulitregion meshing from commandline +step
> file import
>
> Hi Matthias,
> http://forum.freecadweb.org/viewtopic.php?f=18&t=10846&p=103978#p10
> 3978
> whereas still the question remains what exactly means "conformal". Is this
> conformal? Looks like it, no?
> Regards
>
>
> 26.10.2015, 13:28, "Zenker, Dr. Matthias" <Matthias.Zenker at erbe-
> med.com>:
> > Hi,
> >
> > AFAIK gmsh can NOT generate a conformal 3D mesh for a multibody STEP
> file with common interfaces between the bodies, (except for very simple
> cases where "cut and merge faces" works). If I am wrong here, I would be
> most interested to learn how this is achieved.
> > The only way I know to achieve a conformal mesh with OpenSource tools is
> to use Salomé, import the STEP there, and do a partition. Then you can either
> do the meshing in Salomé or use gmsh (which has a better meshing capability
> than Salomé to my experience). In the latter case, export the partitioned
> geometry in brep format, import in gmsh and mesh.
> >
> > HTH,
> >
> > Matthias
> >
> >>  -----Ursprüngliche Nachricht-----
> >>  Von: Anan Im [mailto:ananim343297 at yandex.com]
> >>  Gesendet: Sonntag, 25. Oktober 2015 10:41
> >>  An: gmsh at geuz.org
> >>  Betreff: [Gmsh] conformal mulitregion meshing from commandline +step
> file
> >>  import
> >>
> >>  Hi everybody,
> >>  as to my knowledge gmsh is capable of "conformal" meshing from
> command
> >>  line: For example with Justin Blacks pycalculix on
> >>  http://justinablack.com/pycalculix/ one can use gmsh for it, in this case in
> a
> >>  way, where the meshing functions are written into the .geo file - beneath
> >>  the cad functions.
> >>  On the other hand there are scripts that export step files for meshing to
> >>  gmsh, using its command line interface. Already I experimented with
> >>  exporting a so called compound - but did not succeed in terms of
> conformal
> >>  meshing by now.
> >>
> >>  Which leads to the question:
> >>  Can not one communicate the meshing functions (Mesh.*) from/through
> >>  the command line, if geometry is imported from a cad program, lets say in
> >>  step format, anything different from geo?
> >>
> >>  I might express that I will be very thankful (and not only mine) if there
> gets
> >>  (known) a non interactive conformal meshing interface to the open
> source
> >>  world.
> >>  So if you can exclude that there is a way, which would be a valuable
> >>  information in itself btw, would you put this as "feature request" on the
> list
> >>  of future development?
> >>
> >>  Thanks in advance
> >
> >
> __________________________________________________________
> ___________
> > ERBE Elektromedizin GmbH
> > Firmensitz: 72072 Tuebingen
> > Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede
> > Registergericht: Stuttgart HRB 380137
>



_____________________________________________________________________
ERBE Elektromedizin GmbH
Firmensitz: 72072 Tuebingen
Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede
Registergericht: Stuttgart HRB 380137