What is Reddit's opinion of Gmsh?

From 3.5 billion Reddit comments

You're in /r/FEA, so I assume that you're interested in creating volumetric meshes for finite element analysis. But it looks like CloudCompare's mesh processing is specifically for surface meshes. It probably uses Delaunay Triangulation to generate surface triangles, not to generate volumetric tetrahedra. If so, you'll need to export that surface mesh from CloudCompare and import it into a finite element mesher like Gmsh. But be aware that generating a mesh of hexahedral (brick) elements will require a lot more manual effort than tetrahedral elements. The only mesher I know that focuses on hexahedral elements is SnappyHexMesh.

He's right about gmsh only writing uns grids.

From the documentation : > All the meshes produced by Gmsh are considered as “unstructured”, even if they were generated in a “structured” way (e.g., by extrusion). This implies that the mesh elements are completely defined simply by an ordered list of their nodes, and that no predefined ordering relation is assumed between any two elements.

I know that there is FEA software that is optimized for the case you've described. I remember seeing some posters from someone at ETH Zurich that had voxels from CT data directly converted to hex elements and solved in this specialized software. But now I can't find it.

But it sounds like you're looking for a straightforward conversion so you can spend less time setting up the model. The software I'm remembering is very specialized, so I'm going to guess that quick set-up is not necessarily its priority.

You might have an easier time using the more standard approach: convert your voxel data to a surface model (your segmentation software should be able to this automatically), mesh the surface model with tet elements (Gmsh is one free and open option for this), then solve in any FEA package of your choice (maybe Calculix, or you could use FEBio which is free for research, but not fully free and open).