Hi Mark, to my experience, the "cut and merge" feature works only for simple cases. What you can do is to preprocess your geometry with Salomé. Load the STEP file, modify it if needed, make a partition (that makes the duplicates go away) and save that one as brep, then do the meshing with gmsh. Salomé has also a meshing module, but I find that gmsh is more powerful since it has more meshing algorithms implemented and gives better control over the result.
@Christophe: I don't know how the "partition" operation in Salomé works under the hood - would it be possible to implement it in gmsh? HTH, Matthias > -----Ursprüngliche Nachricht----- > Von: Christophe Geuzaine [mailto:[email protected]] > Gesendet: Donnerstag, 29. Januar 2015 19:18 > An: Mark Smith > Cc: [email protected] > Betreff: Re: [Gmsh] GMSH renumbers elemntaty tags on reload > > > > On 29 Jan 2015, at 13:37, Mark Smith <[email protected]> wrote: > > > > Hi Christophe, > > I agree that saving the cad geometry to a .geo file it is not the way > > to go but at least the surface numbers don't change on reload ;-) I have > some other cad geometry where I don't get this problem, which is why > perhaps you haven't seen it? have you any other suggestions I could try? > > Maybe the best would be for you to send an (small) step file that exhibits the > problem? We could try to see where the non-deterministic numbering > comes from. > > > Regards > > Mark > > > > From: Christophe Geuzaine <[email protected]> > > To: Mark Smith <[email protected]> > > Cc: "[email protected]" <[email protected]> > > Sent: Thursday, January 29, 2015 11:19 AM > > Subject: Re: [Gmsh] GMSH renumbers elemntaty tags on reload > > > > > > > On 29 Jan 2015, at 10:45, Mark Smith <[email protected]> wrote: > > > > > > Hi Christophe, > > > Unfortunately it makes no difference ;-( I used cadexchanger from > > > http://www.cadexchanger.com/ to convert the step file into a .brep file > but this suffers with the same problem. > > > If is do file: save as and type say file2.geo and with the GEO > > > options box "save physical group lables" ONLY ticked I get a file > > > with all the points, lines line loops etc. When I lad this the > > > element tag numbers stay fixed, ( it is relatively simple geometry > > > consisting of volumes bounded by plane surfaces) but I cannot get > > > the surfaces to be filled (rendered) but only crossed faces even > > > when I set > > > > Mark - Do not save your .brep/.step as a .geo! Gmsh is designed to > > work directly with the native files - "translating" them to .geo is > > only there for very specific uses or debugging purposes: the .geo CAD > > kernel is far too rudimentary to handle all the complexities of > > .step/.brep > > > > > > > Geometry.SurfaceType = 2 this makes it difficult to pick surfaces to put > into surface physical groups infact changing Geometry.SurfaceType to 0 1 or 2 > make no difference to the way the surfaces are displayed? > > > Strangely if I load in my cad geometry file Merge "file.STEP"; etc then > > > the > surfaces displayed are as expected if one changes the setting of > Geometry.SurfaceType, any ideas? > > > > > > Thanks in advance. > > > Best regards > > > Mark > > > > > > > > > From: Christophe Geuzaine <[email protected]> > > > To: Mark Smith <[email protected]> > > > Cc: "[email protected]" <[email protected]> > > > Sent: Wednesday, January 28, 2015 7:11 PM > > > Subject: Re: [Gmsh] GMSH renumbers elemntaty tags on reload > > > > > > > > > > On 28 Jan 2015, at 15:36, Mark Smith <[email protected]> wrote: > > > > > > > > > > > > Gmsh version 2.8.5 > > > > > > > > Hi, I load a step file generated in solidworks saved in AP203 or > > > > AP214 format and load in into GMSH using a .geo file with the > > > > following lines > > > > > > > > // in gmsh options-geometry make sure the "cut and merge faces" is > > > > checked // to remove duplicate entities on import of STEP file > > > > Merge "file.STEP"; Geometry.AutoCoherence = 1; Coherence; > > > > > > > > in the options:geometry I get the model to display the surface > > > > labels with their elementary tags number, if I hit reload the tag > numbers change this make defining physical surfaces impossible since the > surfaces shown in the surface physical groups keep changing;-( I have not > had this behaviour before and at this moment it is a show stopper, is there a > way of preventing this behaviour? > > > > > > > > > > I don't see this behavior when I do the same thing over here (note that > "Geometry.AutoCoherence = 1; Coherence;" will have no effect on your > STEP data)... Does adding "Delete All;" before the "Merge" command help? > > > > > > > > > > > > > > > > > > > Thanks in advance > > > > Mark > > > > > > > > > > > > > > > _______________________________________________ > > > > gmsh mailing list > > > > [email protected] > > > > 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 > > > > > > > > > > > > > > > > > > > > > > > > > -- > > Prof. Christophe Geuzaine > > University of Liege, Electrical Engineering and Computer Science > > http://www.montefiore.ulg.ac.be/~geuzaine > > > > > > > > > > -- > Prof. Christophe Geuzaine > University of Liege, Electrical Engineering and Computer Science > http://www.montefiore.ulg.ac.be/~geuzaine > > > > _____________________________________________________________________ ERBE Elektromedizin GmbH Firmensitz: 72072 Tuebingen Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede Registergericht: Stuttgart HRB 380137 _______________________________________________ gmsh mailing list [email protected] http://www.geuz.org/mailman/listinfo/gmsh
