Meshing geometry from STL file

Hello, I have a geometry in STL format coming from segmentation of medical imaging data. If I load the STL in Salome's Mesh module, I can mesh it just fine. However, I first need to modify it with some Geom operations so I loaded it in the Geom module. I was able to modify it as needed, but when I later try to mesh the resulting geometry in the Mesh module, Salome eventually crashes. I tried meshing parts of increasing size of the whole geometry and the meshing works, despite taking superlinearly longer in the size of the geometry [number of triangles]. I understand that the high number [tens of thousands] of triangles in the geometry makes the meshing slow, so I wanted to ask if there is any trick around this, or any alternative workflow I can follow. Thanks for any help! Massimiliano

Hi Massimiliano,

can you check if the crash is caused by an out-of-memory issue by looking at the memory used on your system?

You can change the 3D algorithm to see if it is faster and uses less memory. For instance change from NETGEN to GMSH.

Christophe

Hello Christophe, thanks for the reply! I am running on a workstation with 32 GB of RAM and I've been doing only the 2D meshing for now, so I would rule out that it was an out-of-memory error. However, I will try again right now and keep an eye on the memory usage, and I will also try using Gmsh as a back-end instead of Netgen.

Update: it looks like Gmsh can handle the STL geometry object far more efficiently, which I was able to mesh with reasonable time and memory usage. This is very strange, but I guess it's ultimately an issue with Netgen, not with Salome.