> Le 3 avr. 2019 à 21:51, Gavin Ridley <[email protected]> a écrit : > > Hi Dr. Geuzaine, > > Thanks for your response. I see the problem here now. It doesn't work after > meshing, although the geometry seems to load to the GUI. Unfortunately, I > need to split a surface into two surfaces, and it seems there's no way to do > that to the STEP file using what's available under the OpenCASCADE kernel > right now.
Can you share the STEP file? It should be possible to do what you want directly in Gmsh. > I was hoping to be able to convert the STEP to gmsh-style geometry, then > delete a surface (and its dependent volumes) and replace it with a new, split > one. I'll just have to change the CAD then re-export, I suppose. > > Thanks again! > >> On Wed, Apr 3, 2019 at 3:11 PM Christophe Geuzaine <[email protected]> >> wrote: >> >> >> > On 3 Apr 2019, at 18:23, Gavin Ridley <[email protected]> wrote: >> > >> > Hi, >> > >> > I would just like to note something to the developers regarding a perhaps >> > unnecessary skipping of surfaces in the code. >> > >> > I recently have had to convert a STEP file with fairly complicated >> > geometry to a GEO. >> >> Don't do that. By design, Gmsh never translates from one CAD format to >> another. The "unrolled GEO" feature is there for unrolling complex GEO >> scripts. It can indeed export a limited subset of geometrical entities >> created by other CAD kernels, but it's there only for debugging. >> >> If you want to modify a STEP model, set >> >> SetFactory("OpenCASCADE"); >> >> at the beginning of your script. Since we import STEP models with >> OpenCASCADE, this will allow you to modify the file directly with >> OpenCASCADE. See >> https://gitlab.onelab.info/gmsh/gmsh/blob/master/demos/boolean/import.geo >> for an example. >> >> Christophe >> >> >> >> >> > This is done so that I can split one of the surfaces in the STEP file to >> > set different BCs on different parts of the surface. At the moment, it >> > appears that gmsh will skip several surfaces in the conversion from STEP >> > to geo_unrolled unnecessarily: surfaces were left out from the gmsh file. >> > A warning message comes with this. >> > >> > It seems, however, that the skipped surfaces work fine if you just go back >> > in and add surfaces manually. Gmsh now reads the geo file correctly. >> > >> > So, why are these surfaces being skipped? Is there some ambiguity about >> > their interpretation from STEP? It would be nice to not have to manually >> > go in and add the surfaces. >> > >> > -- >> > Thanks, >> > Gavin Ridley >> > _______________________________________________ >> > gmsh mailing list >> > [email protected] >> > http://onelab.info/mailman/listinfo/gmsh >> >> — >> Prof. Christophe Geuzaine >> University of Liege, Electrical Engineering and Computer Science >> http://www.montefiore.ulg.ac.be/~geuzaine > > > -- > Thanks, > Gavin Ridley
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