Support for COMSOL (.STL) compatible mesh output file

[maxnyf]

I'm wondering if anyone has ideas for how to create a mesh file that is compatible with COMSOL, which accepts .ply, .stl and some others. COMSOL only accepts triangular mesh's for .ply, so the polymesh output to .ply does not work. Trying to convert .vtk from the tri-mesh to .ply or .stl with meshio does not work either.

Ideally I want a polymesh converted to an STL file, not sure if this has been attempted.