Thank you very much! I was indeed missing the "Coherence Mesh". It works great with it, with my real application too!
Elisa Il giorno lun 23 set 2019 alle ore 17:03 Christophe Geuzaine < [email protected]> ha scritto: > > > > On 23 Sep 2019, at 15:23, Elisa Schenone <[email protected]> > wrote: > > > > You were indeed correct. The 1D meshes should be fixed now. > > > > I send you the correct geo file which is a bit closer to the real > application (instead of the ring described in object.stl I will have a more > complicated geometry). > > The three mesh files have been tested with the -check gmsh command and > seem to be correct. > > > > During the 3D mesh generation I still get the error: > > Error : Invalid boundary mesh (segment-facet intersection) on surface > 1, intersection (0.327411,-5.98225,4.06924e-11) > > > > The STL mesh in object.stl is defined by coordinates: there is no > topological link between the triangulation and the discrete curve meshes > that you provide in the circleLine{1,2}.mesh files. You should either > provide the mesh with the full topology; or force Gmsh to merge all > geometrically identical nodes by adding > > Coherence Mesh; > > after you merge object.stl. It's slower (it involves geometrical lookups) > but it works well on your test case : > > > > > > > Christophe > > > > Thanks again for your help, > > Elisa > > > > > > Il giorno ven 20 set 2019 alle ore 17:50 Christophe Geuzaine < > [email protected]> ha scritto: > > > > > > > On 20 Sep 2019, at 09:20, Elisa Schenone <[email protected]> > wrote: > > > > > > Thank you for your quick answer. > > > > > > I'm sorry I missed "BottomBox" surface in the surface loop. Adding it > does not fix the problem. > > > I cannot see why the volume should not be correctly defined since I > use the same 1D entities to define adjacent surfaces. > > > > > > > The 1D mesh in circleLine2.mesh does not seem to be correct: > > > > Info : Running 'gmsh circleLine2.mesh -check' [Gmsh > 4.5.0-git-52cd4c1bd, 1 node, max. 1 thread] > > Info : Started on Fri Sep 20 17:47:42 2019 > > Info : Reading 'circleLine2.mesh'... > > Info : 240 nodes > > Info : 240 edges > > Info : Done reading 'circleLine2.mesh' > > Info : Checking mesh coherence (240 elements)... > > Info : Checking for duplicate nodes... > > Warning : Vertex 22 (-5, -2.09068991909e-14, 0) already exists in the > mesh with tolerance 1.41421e-07: Vertex 21 (-5, -1.98869004218e-14, 0) > > Warning : Vertex 82 (-6.12322976306e-16, -5, 0) already exists in the > mesh with tolerance 1.41421e-07: Vertex 81 (-1.72085002921e-15, -5, 0) > > Warning : Vertex 83 (4.99599990504e-16, -5, 0) already exists in the > mesh with tolerance 1.41421e-07: Vertex 81 (-1.72085002921e-15, -5, 0) > > Warning : Vertex 143 (5, 2.39252994044e-14, 0) already exists in the > mesh with tolerance 1.41421e-07: Vertex 142 (5, 2.29676998584e-14, 0) > > Error : 4 duplicate nodes: see `duplicate_node.pos' > > > > Let's fix that first and see how to proceed from there? > > > > Christophe > > > > > > > > > > > > > Actually, the real application is more complicated than the simplified > example I sent you. Instead of the circle surface I have a quite > complicated geometry coming from a stp from which I extracted the boundary > (the 1D mesh I merge in my geo file). Also, I cannot use OpenCascade since > I need some attractor fields and a boundary layer in my real application. > > > > > > Maybe there is a better way to treat stp file? I need to extract > "manually" its boundary because I'd like to write in my geo something like: > > > bnd[] = Boundary{Surface{14};}; > > > but I don't know a priori the label of the surface I want to extract > the boundary of. > > > > > > Even assuming I know the label from which to extract the 1D boundary, > I still have this kind of error: > > > Error : Invalid boundary mesh (segment-facet intersection) on > surface 121, intersection (50,15,5.57227e-11) > > > I attach a screenshot too. > > > I tried to change the sign of surface 93 (which is innermost circle), > the intersection error moves few elements on the right but is the same. > > > > > > Could it be because of normals? > > > > > > Thank you, > > > Elisa > > > > > > Il giorno gio 19 set 2019 alle ore 19:59 Christophe Geuzaine < > [email protected]> ha scritto: > > > > > > > > > > On 19 Sep 2019, at 11:28, Elisa Schenone <[email protected]> > wrote: > > > > > > > > Dear gmsh developers, > > > > > > > > I'm trying to use gmsh to create a cube mesh with a surface > separated in multiple entities: two concentric circles are inscribed into > the top surface (square). > > > > The external circle comes from a 1D mesh that I merge to my geo > script. > > > > The internal circle has been created only as a workaround since gmsh > could not create the 2D mesh inside the 1D line (file circleLine1.mesh or > circleLine2.mesh). > > > > > > > > Small changes in the script, i.e. characteristic length, line1 or > line2, small circle dimensions, etc., give different errors but none of > these combinations seems to work. > > > > > > > > Also, in case the 2D mesh is correctly generated, the surface mesh > quality is very bad in some points and the 3D mesh cannot be generated. I > tried various options for the 2D and 3D mesh algorithms but none of them > gives good results. > > > > > > > > What am I doing wrong? > > > > > > > > > > The volume does not seem to be defined correctly. In all cases the > surface mesh looks fine to me... > > > > > > Why don't you define all the curves as CAD entities? > > > > > > Christophe > > > > > > > I send you a minimal example of my geo script and the 1D mesh I use > to define the inscribed circle. > > > > > > > > Thank you in advance, > > > > bests, > > > > Elisa > > > > > > > > > > > > > <circleLine2.mesh><testGmsh.geo><circleLine1.mesh>_______________________________________________ > > > > 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 > > > > > > > > > > > > > > > > > > > > > > > > > <ScreenshotGmsh.png><ScreenshotGmsh2.png>_______________________________________________ > > > 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 > > > > > > > > > > > > > > > <ScreenshotGmsh3.png><testGmsh.geo><circleLine2.mesh><object.stl><circleLine1.mesh> > > — > Prof. Christophe Geuzaine > University of Liege, Electrical Engineering and Computer Science > http://www.montefiore.ulg.ac.be/~geuzaine > > > > -- Elisa Schenone, Ph. 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