GMSH mesh not working

Bug Reports
1

I’ve finally got a chance to try the new GMSH function of PrePoMax. I have a simple solid beam with a rectangular cross-section. However, when I try to use the Extrude Mesh function as explained in the YouTube tutorial, nothing happens. I would appreciate guidance in how to solve this, or clarification if this is a bug or not.

The procedure I followed:

  • Open PrePoMax 2.0.0 (both as admin and normal)
  • Create a new model
  • Import the *.step file
  • Set up the Meshing Parameters for the part
  • Set up the Extrude mesh
  • Tried to visualize the mesh

A detailed image:

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image1350×701 46.4 KB

The log file after hitting the visualization icon:

12/05/23 22:59:05   Running command: \PrePoMax v2.0.0\PrePoMax v2.0.0\lib\GmshMesher.exe gmshData
12/05/23 22:59:05   Info    : Meshing 1D...
12/05/23 22:59:05   Info    : Done meshing 1D (Wall 0s, CPU 0s)
12/05/23 22:59:05   Info    : 0 nodes 0 elements
12/05/23 22:59:05   Info    : Meshing 1D...
12/05/23 22:59:05   Info    : Done meshing 1D (Wall 0s, CPU 0s)
12/05/23 22:59:05   Info    : Meshing 2D...
12/05/23 22:59:05   Info    : Done meshing 2D (Wall 0s, CPU 0s)
12/05/23 22:59:05   Info    : 0 nodes 0 elements
12/05/23 22:59:05   Info    : Writing '\PrePoMax v2.0.0\PrePoMax v2.0.0\Temp\mesh.inp'...
12/05/23 22:59:05   Warning : Unknown OpenCASCADE entity of dimension 0 with tag 0
12/05/23 22:59:05   Info    : Done writing '\PrePoMax v2.0.0\PrePoMax v2.0.0\Temp\mesh.inp'
12/05/23 22:59:05   Warning : Unknown OpenCASCADE entity of dimension 3 with tag 1
12/05/23 22:59:05   Meshing done.
12/05/23 22:59:05   
12/05/23 22:59:05   Elapsed time [s]: 0
12/05/23 22:59:05   
12/05/23 22:59:05   Info: Meshing 1D...
12/05/23 22:59:05   Info: Done meshing 1D (Wall 0s, CPU 0s)
12/05/23 22:59:05   Info: 0 nodes 0 elements
12/05/23 22:59:05   Warning: Unknown OpenCASCADE entity of dimension 0 with tag 0
12/05/23 22:59:05   Warning: Unknown OpenCASCADE entity of dimension 3 with tag 1
12/05/23 22:59:05   Info: Meshing 1D...
12/05/23 22:59:05   Info: Done meshing 1D (Wall 0s, CPU 0s)
12/05/23 22:59:05   Info: Meshing 2D...
12/05/23 22:59:05   Info: Done meshing 2D (Wall 0s, CPU 0s)
12/05/23 22:59:05   Info: 0 nodes 0 elements
12/05/23 22:59:05   Info: Writing '\PrePoMax v2.0.0\PrePoMax v2.0.0\Temp\mesh.inp'...
12/05/23 22:59:05   Info: Done writing '\PrePoMax v2.0.0\PrePoMax v2.0.0\Temp\mesh.inp'
12/05/23 22:59:05   
12/05/23 22:59:05   
12/05/23 22:59:05   
12/05/23 22:59:05   Elapsed time [s]: 0.298568
12/05/23 22:59:05

The PrePoMax file:
bug_gmsh.pmx (8.4 KB)

This happens for both 1.5.2 and 2.0.0 versions.

2

@lucas_bueno - You need to pick a Recombine Method eg. Simple, Blossom, etc. This combines two adjacent tet elements into a single hex element

image

3

It still does not work for me :disappointed_relieved:.

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image985×544 35.1 KB

It says that “surface 6 does not exist”. Not sure why.

12/06/23 08:59:54   Running command: \PrePoMax v2.0.0\PrePoMax v2.0.0\lib\GmshMesher.exe gmshData
12/06/23 08:59:54   Info    : Meshing 1D...
12/06/23 08:59:54   Info    : Done meshing 1D (Wall 0s, CPU 0s)
12/06/23 08:59:54   Info    : 0 nodes 0 elements
12/06/23 08:59:54   Error   : Surface 6 does not exist
12/06/23 08:59:54   Info: Meshing 1D...
12/06/23 08:59:54   Info: Done meshing 1D (Wall 0s, CPU 0s)
12/06/23 08:59:54   Info: 0 nodes 0 elements
12/06/23 08:59:54   Error: Surface 6 does not exist
12/06/23 08:59:54   
12/06/23 08:59:54   External component raised an exception.
12/06/23 08:59:54   
12/06/23 08:59:54   Elapsed time [s]: 0.2924796
4

Strange, it works for me in 2.0.0:

mesh
mesh1392×712 146 KB

6

It also works for me. Does the preview button work?

7

I will verify if I can make it run on another computer I have access to. Maybe it is something related to the software installed on my machine.

The error message I got was raised when I tried to visualize it. So neither the preview nor the “Create mesh” buttons work.

8

I’ve managed to make it work without problems. I think it is something related to my computer.

image

@Matej are you aware of any requisites for GMSH to work on a computer? Maybe some drivers, open-cascade version… I tried to upgrade to Win11 and update NVIDIA drivers but nothing worked.

9

Ok, it seems standalone GMSH version 4.11.1 is working without problems. Now I don’t have any idea why the PrePoMax version is not functioning :disappointed_relieved:.

image
image888×761 51.4 KB

10

I have no idea what might be missing. I found out recently that some Gmsh settings are stored globally. Did you have Gmsh installed previously, and did you change any Gmsh settings?

Can you try to move the PrePoMax to a short as possible folder like c:\PrePoMax

1 Like
11

That explains a lot. Yes, I previously used GMSH to create CFD meshes with many custom settings. That’s very likely the source of the problem.

It worked, Matej. Thank you. Hopefully, this will help somebody with the same problem in the future.

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image1240×672 136 KB

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image1129×685 70.6 KB

Best regards,
Lucas.

1 Like
12

I will consider this problem as solved.

1 Like