How to get vertices of interior boundary?

dolfinx
3

Since the interface is between marked with different tags, I would suggest:

  1. loop through all facets
    1.b get the facet to cell connectivity, check for cell tags and that they have two unique cell tags. Add to a list
  2. For the accumulated list of interface facets, use compute_incident_entities(mesh, entities, 1,0)

This has for instance done in: Get boundary points from custom cell tags - #4 by dokken