@kamyar The approach you show here is the one I use because I couldn’t find a better way.
However, it does mean that you cannot take advantages of the actor methods to hde/show Edges etc. and instead you have to manage visiblity of the actors in your own code. Which isnl’t horrible, but is a pain.
It seems that Paraview has a much more convenient way to handle this - maybe I need to look at the Paraview code… Paraview does seem to use edge flags, but they can’t be using the standard VTK edge flags because they are pretty much unusable for this task as shown by @Flagada above.
It seems that either very few people are using higher order cells otherwise there woudl be an easier way of doing this by now.
Or maybe there is an easy way, and I just don’t know what it is…
Doug