vtkCollection... am I using it well?

Perfect!

Still one more question: in another issue you suggested to try using xarray for metadata etc…

Now suppose I’d like to store my (several) vtk objects in a data structure together with their metadata, and to be able to search, select, etc., the vtk objects based on the metadata.

By using xarray I could store the vtk object (actually the pointer to the vtk object) in a “column” (or dimension in xarray terms) and the metadata in other columns. Do you see any problem with this data structure?

To further explore this idea, probably the same can be done also with Pandas. Which one would be better in your opinion, Pandas or xarray?

Many thanks!