Question to ogstools.msh2vtu - How to get one vtu with all physical groups as materials ID included?

I meshed with GMSH (Python-API) a domain with two soil layers and two BHE’s as line elements included for a simulation with the Heat_Transport_BHE-Process in OGS. I tag the volumes according to soil layer as two physicalGroups and the lines according to the BHE as additional two physicalGroups. The mesh inside GMSH looks fine. Now I want to convert the GMSH .msh with the ogstools.msh2vtu and run into a problem: msh2vtu produce different vtu-files according to the physicalGroups, but I need one vtu with the soil layers and the BHE’s inside for the Heat_Transport_BHE-Simulation. Is it possible to get it with msh2vtu? I also try to convert the .msh with GMSH2OGS Binary, but the result with the materialsID’s is not as expected. I can also share the Jupyter-Notebook, where I programmed the mesh - currently I can not upload it.

Dear Max,

Can you tell me what exactly was the problem with GMSH2OGS? What went wrong with the material IDs?


Dear Haibing,

GMSH2OGS set the material IDs according to the entities in GMSH, the physical group is ignored. I tried a new semi structured surface meshing and then each soil layer consists of 5 volume entities in GMSH, which I merge afterwards in a physical group for each soil layer. See attached picture, which is the results from GMSH2OGS conversion.

msh2vtu set the material ID according to the physical group and has also the capability to export surface meshes for setting boundary conditions, which give a much more cleaner setup to build up a simulation model for Heat_Transport_BHE. In the meanwhile I looked up in the source code of msh2vtu and with a little adjustment of the detected elements of dim3 (include line elements - not a nice way, but the BHE-Line-Elements then included in the domain mesh) it works fine. See according picture:

I think, we can implement the change of the dim3-elements in msh2vtu in dependency of a new flag -bhe or so. We can chat in Mattermost, how it can be implemented exactly.


msh2vtu is now living also in ogstools and since I volunteered in replacing Domink as the maintainer, feel free to involve me in the process.

Best regards,