Problem import 3D file .msh

General Discussion
1

hello,
i’m trying to import 3D mesh from gmsh by using:
load"gmsh"
mesh3 Th=gmshload3(“Part1.msh”);
plot(Th,cmm=“Th mesh read from GMSH”,wait=1);
savemesh(Th,“Th3.mesh”);
but it give me :
edges in 3D mesh are not considered yet in freefem++, skeep data
Element of type 0 is not considered in Freefem++
can you help me to overcome this problem?

2

We can’t help you without the .geo and how you generate your .mesh. My guess is that you exported all the physical entities, which is not needed. Also, I think this is mostly a warning, is your Th3.mesh actually wrong? What gives ffmedit Th3.mesh?

3

Thank you for your response .
in order to import .msh file from gmsh to freefeem++ I do the folowing steps :
1- i open the .stp file in gmsh

2- i add volume in physical groups, and i create .geo file :
Merge “Part1.stp”;
Physical Volume(1) = {1};

3-i generate 3D mesh

4- i export a .msh file

5- i create .edp file wich contain:
load"gmsh"
mesh3 Th=gmshload3(“Part1.msh”);
plot(Th,cmm=“Th mesh read from GMSH”,wait=1);
savemesh(Th,“Th3.mesh”);

and i open it with freefem++

and i received this error :
You chose the file “C:\Users\chaim\Desktop\test3.txt”
– FreeFem++ v4.7 (Fri, Sep 04, 2020 1:37:14 AM - git v4.7-2-g3716c303)
Load: lg_fem lg_mesh lg_mesh3 eigenvalue
1 : load"gmsh"(load: loadLibary C:\Program Files (x86)\FreeFem++\.\gmsh = 0)
2 : mesh3 Th=gmshload3(“Part1.msh”);
3 : plot(Th,cmm=“Th mesh read from GMSH”,wait=1);
4 : savemesh(Th,“Th3.mesh”);
5 : sizestack + 1024 =1256 ( 232 )

edges in 3D mesh are not considered yet in freefem++, skeep data
0 tetrahedrons
0 triangles
1 numElements
Return type false, your mesh is MeshS type, use gmshloadS function
current line = 2
Assertion fail : (0)
line :1037, in file gmsh.cpp
Assertion fail : (0)
line :1037, in file gmsh.cpp
err code 6 , mpirank 0
try getConsole C:\Users\chaim\Desktop\test3.txttest3.txt.log (826 Bytes)docs.rar (11.4 KB)

4

How do you export the .msh file?

5

i do just :file–> export–> .msh extension

6

Are you using Gmsh format version 2 or version 4?

7

i use gmsh version 4.6

8

You are not answering my question. Are you exporting the .msh using Gmsh format version 2 or version 4?

Edit: I see from your attached file that you are using format version 4. You need to switch to format version 2.

$ more Part1.msh
$MeshFormat
4.1 0 8
[...]
9

thank you fror your help.
it works now.

10

Use Export instead of Save Mesh.