Exporting built-in Firedrake mesh to gmsh

[sarshia]

Hello, is there a way to export a built-in Firedrake mesh to gmsh? For example, if I create a UnitCubeMesh in Firedrake and want to export its node sets, element sets, etc. all to a .msh file for visualization in gmsh. I am able to write the mesh to .pvd but not to .msh.

[connorjward]

Unfortunately I do not think that this is possible. Internally we rely on PETSc DMPlex for our mesh representation, and DMPlex only has routines for reading to gmsh files, not writing to them.

[sarshia]

Got it, and just to clarify does this include even after we write the mesh to .pvd? In other words, do you know if the node/element data is retained in the .pvd file in a way that could then be exported to gmsh?

[connorjward]

At that point you are outside the Firedrake ecosystem so I'm not sure. The Python package meshio appears to support loading and writing VTK and .msh files though so might do what you want. I recall this being used by some Firedrake users in the past.