[Gmsh] boolean partitioning

[Christophe Geuzaine]

> On 3 May 2017, at 10:36, Zenker, Dr. Matthias <Matthias.Zenker at erbe-med.com> wrote:
> 
> Thank you!
> 
> Does it work also with STEP data imported from CAD?

Yes!

> 
> Matthias
> 
>> -----Ursprüngliche Nachricht-----
>> Von: Christophe Geuzaine [mailto:cgeuzaine at ulg.ac.be]
>> Gesendet: Mittwoch, 3. Mai 2017 10:34
>> An: Zenker, Dr. Matthias
>> Cc: andrew; gmsh at onelab.info
>> Betreff: Re: [Gmsh] boolean partitioning
>> 
>> 
>> Have a look at the new boolean examples, e.g.
>> 
>> https://urldefense.proofpoint.com/v2/url?u=http-
>> 3A__gitlab.onelab.info_gmsh_gmsh_blob_master_demos_boolean_comps
>> olid.geo&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-IVyyYW-
>> Ff2gY&r=3enlI3TuQDmO9BnMCnxq2Mfm4tAO6Z3_Ae1Yc57DMr4&m=2mpe
>> DRom3Noibyq90RXwKUzWF1rJRcO6ZGHMbIFv5so&s=xHnc46KE5L6ugWGTfy
>> _YoQoMQy6J3MVGy7jh30SFFLo&e=
>> https://urldefense.proofpoint.com/v2/url?u=http-
>> 3A__gitlab.onelab.info_gmsh_gmsh_blob_master_demos_boolean_comps
>> olid2.geo&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-IVyyYW-
>> Ff2gY&r=3enlI3TuQDmO9BnMCnxq2Mfm4tAO6Z3_Ae1Yc57DMr4&m=2mpe
>> DRom3Noibyq90RXwKUzWF1rJRcO6ZGHMbIFv5so&s=NcLs864W46WNKIoHZ
>> E2UBNMZprqYawTICL8jZpa7UfM&e=
>> 
>> BooleanFragments does exactly what you need.
>> 
>> 
>>> On 3 May 2017, at 10:14, Zenker, Dr. Matthias <Matthias.Zenker at erbe-
>> med.com> wrote:
>>> 
>>> Hi,
>>> 
>>> I would also be interested in that functionality. It would resolve the old
>> “duplicated surfaces” problem that forced me (and others) to leave gmsh
>> and do the meshing with Salomé, even though IMHO gmsh does a better job
>> especially in 3D meshing – in Salomé, only netgen is available as 3D algorithm
>> in the free version.
>>> BTW there seems to be a macro permitting to use gmsh in Salomé, see
>>> this post at the Salomé forum:
>>> https://urldefense.proofpoint.com/v2/url?u=http-3A__salome-
>> 2Dplatform.
>>> org_forum_forum-5F12_953948027-
>> 23494327180&d=DwIFaQ&c=7vND7vRFB1FzfxRX
>>> c-X80O-MJSZd5Q-IVyyYW-
>> Ff2gY&r=3enlI3TuQDmO9BnMCnxq2Mfm4tAO6Z3_Ae1Yc57D
>>> 
>> Mr4&m=2mpeDRom3Noibyq90RXwKUzWF1rJRcO6ZGHMbIFv5so&s=bweZW
>> T8PCF107y-xPl
>>> l629T-vfFUIANxsy48ZRnkG6Q&e=
>>> I haven’t tested it, though.
>>> To export a geometry from Salomé to gmsh, I have sometimes had success
>> using brep format.
>>> 
>>> Matthias
>>> 
>>> Von: andrew [mailto:armitatz at gmail.com]
>>> Gesendet: Dienstag, 2. Mai 2017 19:58
>>> An: gmsh at onelab.info
>>> Betreff: [Gmsh] boolean partitioning
>>> 
>>> 
>>> hi,
>>> 
>>> In Salome which uses the opencascade model there is a Boolean operation
>> called partition. With this you can create a solid from two others but with a
>> shared face. A usage of that is the creation of meshes with internal walls in it
>> with zero thickness aka 'baffles'. Is there a procedure in gmsh that can give
>> the same results given that it has implemented the same opencascade
>> model? Obviously there is a way to have such results if you give the precise
>> geometry but sometimes it is very difficult to cut geometries and it is easier if
>> gmsh could do that.
>>> 
>>> Attached is an image of a mesh with internal baffles created with
>> partitioning and the geometry that created it. I would prefer t if gmsh could
>> do the meshing but I haven't found a way to load the geometry to gmsh from
>> Salome.
>>> 
>>> kind regards
>>> 
>>> Andrew
>>> 
>>> 
>>> Erbe Elektromedizin GmbH Firmensitz: 72072 Tuebingen
>>> Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede Registergericht:
>>> Stuttgart HRB 380137
>>> 
>>> _______________________________________________
>>> gmsh mailing list
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>>> https://urldefense.proofpoint.com/v2/url?u=http-
>> 3A__onelab.info_mailma
>>> n_listinfo_gmsh&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-
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>> tgduaWTphlg&e
>>> =
>> 
>> --
>> Prof. Christophe Geuzaine
>> University of Liege, Electrical Engineering and Computer Science
>> https://urldefense.proofpoint.com/v2/url?u=http-
>> 3A__www.montefiore.ulg.ac.be_-
>> 7Egeuzaine&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-IVyyYW-
>> Ff2gY&r=3enlI3TuQDmO9BnMCnxq2Mfm4tAO6Z3_Ae1Yc57DMr4&m=2mpe
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>> 
>> Free software: https://urldefense.proofpoint.com/v2/url?u=http-
>> 3A__gmsh.info&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-
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>> https://urldefense.proofpoint.com/v2/url?u=http-
>> 3A__onelab.info&d=DwIFaQ&c=7vND7vRFB1FzfxRXc-X80O-MJSZd5Q-
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> 
> ________________________________
> 
> Erbe Elektromedizin GmbH Firmensitz: 72072 Tuebingen Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede Registergericht: Stuttgart HRB 380137
> 

-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine

Free software: http://gmsh.info | http://getdp.info | http://onelab.info