RuntimeError: Cannot recognise cell type. Unknown value: hexahedron_20

dolfinx
1

Hi
I have created a mesh of Quadratic Hexahedron elements using SALOME. I have converted it to XDMF using meshio. The TopologyType is set as “Hexahedron_20” by meshio which is correct as per the XDMF format available here.

But when I try to read the XDMF file using dolfinx, I get an error mentioned in the title.
I searched the Github repository of dolfinx for quadratic meshes. I saw examples of creating meshes using gmsh or using the create_mesh function by manually creating the ufl.Mesh.

Is this a bug? Or do I need to use h5py to manually create the quadratic mesh as in the test cases here?

2

Dolfinx does does not support hexahedron 20 meshes, But hexahedron_27 meshes (Which is a complete second order Lagrange space).