[Gmsh] Problem meshing imported STEP file
Hello everyone, I would like to mesh a .STEP file (a picture is attached). But just running Merge "part.STEP"; Mesh 3; gives me the following errors: Error : No tetrahedra in region 1 Info: 3D refinement terminated (274 nodes total): Info: - 0 Delaunay cavities modified for star shapeness Info: - 0 nodes could not be inserted Info: - 0 tetrahedra created in 0.000178 sec. (0 tets/s) Error : No elements in volume 1 I tried to define new volumes and I managed to mesh some parts of the object, but I was never able to mesh everything. Do you have some ideas what I could do? Thanks, Michael ___ gmsh mailing list gmsh@onelab.info http://onelab.info/mailman/listinfo/gmsh
Re: [Gmsh] Problem meshing imported STEP file
> On 28 Apr 2020, at 12:20, Michael Enders wrote: > > Hello everyone, > > I would like to mesh a .STEP file (a picture is attached). But just running > > Merge "part.STEP"; > Mesh 3; > > gives me the following errors: > > Error : No tetrahedra in region 1 > Info: 3D refinement terminated (274 nodes total): > Info: - 0 Delaunay cavities modified for star shapeness > Info: - 0 nodes could not be inserted > Info: - 0 tetrahedra created in 0.000178 sec. (0 tets/s) > Error : No elements in volume 1 > > I tried to define new volumes and I managed to mesh some parts of the object, > but I was never able to mesh everything. Do you have some ideas what I could > do? > Can you send the .step file ? Christophe > Thanks, > Michael > ___ > gmsh mailing list > gmsh@onelab.info > http://onelab.info/mailman/listinfo/gmsh — Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine ___ gmsh mailing list gmsh@onelab.info http://onelab.info/mailman/listinfo/gmsh
Re: [Gmsh] export .step file without duplicated geometry
Hi Kelal, Indeed it's a known issue with the STEP exporter. Let's continue the discussion here: https://gitlab.onelab.info/gmsh/gmsh/-/issues/624 We currently create a single compound for the model, and use the "STEPControl_AsIs" OpenCASCADE option to export STEP files. It's maybe not what we should do... Christophe > On 28 Apr 2020, at 12:30, Kelal Raschket wrote: > > Hello gmsh community, > > I found the following discussion in the gmsh mailing archive: > http://onelab.info/pipermail/gmsh/2018/012233.html. > There they discussed how to export a geometry in gmsh using the OpenCASCADE > kernel. I used the .geo file attatched there and exported it as .step file as > well. When I then loaded the resulting .step file into gmsh again to see if > everything worked like expected I recognized that points, curves and surfaces > are loaded multiple times. What can I do to only save all my geometry once? > And a second, related question: Is there a similar function in gmsh for > deciding to either save all the created geometry or only the ones also in a > physical group? Something identical like the "Mesh.SaveAll" function just for > geometry. > > Thank you, > Kelal Raschket > ___ > gmsh mailing list > gmsh@onelab.info > http://onelab.info/mailman/listinfo/gmsh — Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine ___ gmsh mailing list gmsh@onelab.info http://onelab.info/mailman/listinfo/gmsh
Re: [Gmsh] Problem meshing imported STEP file
Yes, of course. From: Christophe Geuzaine Sent: 28 April 2020 13:34 To: Michael Enders Cc: gmsh@onelab.info Subject: Re: [Gmsh] Problem meshing imported STEP file > On 28 Apr 2020, at 12:20, Michael Enders wrote: > > Hello everyone, > > I would like to mesh a .STEP file (a picture is attached). But just running > > Merge "part.STEP"; > Mesh 3; > > gives me the following errors: > > Error : No tetrahedra in region 1 > Info: 3D refinement terminated (274 nodes total): > Info: - 0 Delaunay cavities modified for star shapeness > Info: - 0 nodes could not be inserted > Info: - 0 tetrahedra created in 0.000178 sec. (0 tets/s) > Error : No elements in volume 1 > > I tried to define new volumes and I managed to mesh some parts of the object, > but I was never able to mesh everything. Do you have some ideas what I could > do? > Can you send the .step file ? Christophe > Thanks, > Michael > ___ > gmsh mailing list > gmsh@onelab.info > http://onelab.info/mailman/listinfo/gmsh — Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine part.STEP Description: part.STEP ___ gmsh mailing list gmsh@onelab.info http://onelab.info/mailman/listinfo/gmsh
[Gmsh] BooleanFragments on tiny scale
Dear developers and users,
is there a way, to apply BooleanFragments (and others?) also on a very
tiny scale?
-> Please find attached a MWE, illustrating that this operation fails on
a small scale even with reducing BooleanTolerance (ln 17/18).
Best regards,
Mathias
--
Dr. Mathias Scheunert
Institute of Geophysics and Geoinformatics, TU Bergakademie Freiberg
Gustav-Zeuner-Str. 12, D-09596 Freiberg
Tel.: +493731393630
SetFactory("OpenCASCADE");
// Create line from points.
pt_id = newp;
Point(pt_id+0) = {-1e-05, 0, 0};
Point(pt_id+1) = {1e-05, 0, 0};
ln_id = newl;
Line(ln_id) = {pt_id+0, pt_id+1};
// Create surfaces.
fc_id = news;
domain_r = 3e-07;
Disk(fc_id+0) = {-5e-06, 0, 0,domain_r};
Disk(fc_id+1) = { 5e-06, 0, 0, 10*domain_r};
// Intersect surfaces with line.
tol = 1e-6; // no cuts at all
//tol = 1e-13; // only large disc is halfed
Geometry.ToleranceBoolean = tol;
frag_ents() = BooleanFragments{Curve{ln_id}; Delete;}{Surface{fc_id+0,
fc_id+1}; Delete;};
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Re: [Gmsh] BooleanFragments on tiny scale
> On 28 Apr 2020, at 17:49, Mathias Scheunert > wrote: > > Dear developers and users, > > is there a way, to apply BooleanFragments (and others?) also on a very tiny > scale? > > -> Please find attached a MWE, illustrating that this operation fails on a > small scale even with reducing BooleanTolerance (ln 17/18). > No, unfortunately OpenCASCADE has a fixed tolerance and does not work for very small values of coordinates. The solution is e.g. to work close to 1, then rescale the coordinates when saving the mesh with Mesh.ScalingFactor. Christophe > Best regards, > Mathias > > -- > Dr. Mathias Scheunert > Institute of Geophysics and Geoinformatics, TU Bergakademie Freiberg > Gustav-Zeuner-Str. 12, D-09596 Freiberg > Tel.: +493731393630 > > ___ > gmsh mailing list > gmsh@onelab.info > http://onelab.info/mailman/listinfo/gmsh — Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine ___ gmsh mailing list gmsh@onelab.info http://onelab.info/mailman/listinfo/gmsh
