> On 22 Oct 2020, at 12:56, Marco Antolovic <[email protected]> wrote: > > Hi all, > > I'm trying to find the best way to approach the following problem: > > I have a parallelepiped with the edge alone z much smaller than that along x > and y (this is typical, for example, > for PCB traces) and I would like to guarantee, in the volume, a predefined > number of layers (np_layers) along z > edge. > > If I build the structure in gmsh this is quite simple to obtain by saying: > > SetFactory("OpenCASCADE"); > thickness = 140e-6; > nr_layers = 4; > surf=newreg; > Rectangle(surf)={.001,0,0,.001,.001,0}; > Extruded_surf() = Extrude { 0,0, thickness } { Surface{surf}; > Layers{nr_layers}; Recombine;}; > > But how can I apply this in case the parallelepiped is coming from a step > file? The command above > (Extrude{...}{... Layers{}}) can't be used.
Indeed, we would need to "reverse engineer" the fact that the volume has indeed been created by extrusion. See https://gitlab.onelab.info/gmsh/gmsh/-/issues/929 for the issue tracking this feature request. Christophe > > I was thinking about slicing the Volume with some planes (see example below) > > SetFactory("OpenCASCADE"); > thickness = 140e-6; > nr_layers = 4; > surf=newreg; > Rectangle(surf)={.001,0,0,.001,.001,0}; > Extruded_surf() = Extrude { 0,0, thickness } { Surface{surf};}; > vol() = Extruded_surf(1); > For i In {1:nr_layers-1} > surf1(i-1)=newreg; > Rectangle(surf1(i-1)) = {.001, 0, thickness/nr_layers*i, .001, .001}; > EndFor > results() = BooleanFragments{Volume{vol()};Delete;}{Surface{surf1()}; > Delete;}; > > but when trying to recombine the triangles in the layers I get the following > error: > > Error : Pyramid top vertex already classified on volume 2 (!= 3) - > non-manifold quad boundaries not supported > yet > > Any suggestion on how to address the issue is much appreciated. > > Regards, > > Marco > > _______________________________________________ > gmsh mailing list > [email protected] > http://onelab.info/mailman/listinfo/gmsh — Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://people.montefiore.ulg.ac.be/geuzaine _______________________________________________ gmsh mailing list [email protected] http://onelab.info/mailman/listinfo/gmsh
