Gmsh import problem

Mesh generators, CAD programs, and other tools
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spacether
Posts: 10
Joined: 09 Feb 2014, 22:40
Antispam: Yes

Gmsh import problem

Post by spacether »

Has anyone had Gmsh import problems?
I'm loading in a volume meshed with second order hexahedron elements.
The elements load in fine, but my surfaces are not selectable.

My methodology:
load in brep file
add 1 volume physical group

Gmsh mesh part
1d
2d
3d

Automatic 2D Alg
Delaunay 3D Alg
Blossom 2D recomb alg

uncheck Recomb all triang mesh

All Hexas Subdivision Alg
No split Remesh Alg
Harmonic Remeshing parameterization
1 Smoothing Steps
1 Element size factor
0 1e+022 Min/Max elem size
2 Element Order

Advanced:
Compute Element sizes using pt values
Extend element sizes from boundaries

Then I export the .msh file.
I've tried exporting with and without the Save All checkbox selected.
Neither option shows up with areas that are selectable in ElmerGui.

See the attached screenshot showing the Gmsh entities. Note that the surface is meshed with quads.
Has anyone else had this problem with surfaces not being selectable?
This was not a problem using 1st order hexahedrons.
Attachments
screen capture showing the msh entities.
screen capture showing the msh entities.
hex_2nd_gmsh_screencap.jpg (59.59 KiB) Viewed 10776 times
m10_hex_2nd.msh
final mesh file
(684.48 KiB) Downloaded 627 times
2014-02-17_cant_beam.brep
source brep file
(5.68 KiB) Downloaded 559 times
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Gmsh import problem

Post by mzenker »

Hi,

to my experience, ElmerGUI has general problems with entity selection in 3D, also with triangular surfaces.

If you want to find out surface numbers, re-convert the mesh to gmsh format using

elmergrid 2 4 mymesh

and inspect the mesh with gmsh. This step is needed since entities are renumbered at mesh import.

HTH,

Matthias
jesusnv
Posts: 7
Joined: 24 Sep 2014, 10:50
Antispam: Yes

Re: Gmsh import problem

Post by jesusnv »

Good morning;

I want to know which geometry files can open with gmsh?? Maybe autocad file or similar. I tried with .stl files but I only saw the mesh, I couldn´t saw the points, lines or surfaces.. What is the problem???

Can someone help me??

Thank you and have a nice day.
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Gmsh import problem

Post by mzenker »

jesusnv
Posts: 7
Joined: 24 Sep 2014, 10:50
Antispam: Yes

Re: Gmsh import problem

Post by jesusnv »

Hi!

It is possible that I download the gmsh version 2.9.0 for windows?? or this version is only for linux?? In this moment I have the gmsh 2.8.5 , but I want the last version.

thanks
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Gmsh import problem

Post by mzenker »

2.8.5 is the stable release, but there are nightly snapshots.
http://www.geuz.org/gmsh

Matthias
jesusnv
Posts: 7
Joined: 24 Sep 2014, 10:50
Antispam: Yes

Re: Gmsh import problem

Post by jesusnv »

Hi!!

I could open a IGS file yesterday, and I worked with this and finally I did the mesh without problem. But today I received a new geometry file in IGS and I can´t open this file with my gmsh 2.8.5... I dont now why..

thanks
mzenker
Posts: 1999
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Gmsh import problem

Post by mzenker »

Hi,

to my experience, gmsh prefers STEP over IGES. So you might try to get your geometry converted to STEP and try that one.
You can also check under Tools->Options->Geometry->General that all "healing options" are unchecked, sometimes they fail and nothing is shown.
For error messages, look at the message console (Ctrl-l to make it appear).

In general, you'd better ask this kind of questions at the gmsh mailing list where the real experts are...


Matthias
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