On 05 Apr 2013, at 12:45, Christophe Geuzaine <[email protected]> wrote:
> > On 19 Mar 2013, at 11:14, NENNIG Benoit <[email protected]> wrote: > >> Dear gmsh team, >> >> I would like to switch orientation of surfaces coming from a part design by >> FreeCAD and export in step format. >> - I try to reverse normal orientation in the FreeCAD (MyShape.reverse() ??) >> but in gmsh nothing change (however I am not sure of how is made the export >> in step and if step can store inward normal vector....) >> - I try the "classical" gmsh version : >> Physical Surface (1) = {-SufList[]}; >> It works for .msh format (native gmsh) but in .mesh (inria format) only the >> label is change into -label but the orientation remain the same... >> - flip all mesh normal is not possible because I have other shape in my >> mesh, not concerned with this problem. >> >> Do you have an idea ? >> > > I think we should provide an explicit interface to orient (or just "revert" > w.r.t. the natural orientation) the mesh. > > The new MSH3 format will not change the orientation of the elements at > "write" time, as this makes the on-disk representation different from the > "in-memory" representation. The ".mesh" format is already "correct" in that > sense. > > I've filed this as https://geuz.org/trac/gmsh/ticket/191 > This is now fixed in SVN r15204. You can simply use the following commands in your .geo file: Reverse Surface { ... }; or Reverse Line { ... }; to reverse the mesh orientation (compared to the natural orientation, which matches the orientation of the underlying geometrical entity). > >> Thanks! >> >> Benoit >> >> ps : In .msh format, I observe that if the surface has strong variation >> close a small inner corner, the element orientation may be random close to >> the inner corner if there is only one element on the corner thickness. >> > > Hmm... When there is no inner vertex we resort to a simple geometrical test > at the barycenter of an element. Could you send a simple example? > > Thanks, > > Christophe > > > > >> >> _______________________________________________ >> 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 _______________________________________________ gmsh mailing list [email protected] http://www.geuz.org/mailman/listinfo/gmsh
