[Gmsh] GMSH renumbers elemntaty tags on reload

[Christophe Geuzaine]

> On 29 Jan 2015, at 13:37, Mark Smith <piedycat at yahoo.com> 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 <cgeuzaine at ulg.ac.be>
> To: Mark Smith <piedycat at yahoo.com> 
> Cc: "gmsh at geuz.org" <gmsh at geuz.org> 
> 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 <piedycat at yahoo.com> 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 <cgeuzaine at ulg.ac.be>
> > To: Mark Smith <piedycat at yahoo.com> 
> > Cc: "gmsh at geuz.org" <gmsh at geuz.org> 
> > 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 <piedycat at yahoo.com> 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
> > 
> > > 
> > > 
> > > _______________________________________________
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> > > 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
> 
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> > 
> 
> -- 
> 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