Hi!
That’s what I kind of suspected.
What I am trying to do is to is to add a simple, decently-fast Python wrapper to expose our home-grown file format as a vtk HTG object (instead of a bit clunky VisIt plugin, which is another story). Working on the aforementioned tutorials, I have a working skeleton code (all the way down to a ParaView plugin), but it is rather slow to ingest production-scale files (say, ~10M leaf nodes at ~four refinement levels). As above, generating the descriptor and using it would actually seem decently fast on small files, and I would have been pretty glad to have had it working quick even with a bit of a hacky solution :). Any help to better ingest the structure would indeed be appreciated!
Specifically, the context is the VLSV file format, from which we can consider that we store the mesh structure as a list of unique, global CellIDs, one for each leaf. I would rather construct a mapping of these CellIDs to the HTG global indices, but I haven’t delved yet deep enough to the HTG spec to do that, nor do I know of a method for constructing the HTG without walking the trees with the VTK wrapper (rather slow) or building the descriptor (surprisingly fast even with just a Python loop).