Okay, here’s a strange suggestion:
actor.GetProperty().EdgeVisibilityOn();
actor.GetProperty().VertexVisibilityOn();
actor.GetProperty().SetPointSize(10);
If that works, my hunch is right. I’ve always thought there was a bug where the opengl polydata mapper only respected the vertex visibility setting when edge visibility is switched on. Let me know what you see. I think this is an easy fix.
VTK 9.4 was just released a few days ago but it’s release candidates have been out for some weeks now, so I thought you were testing those wheels. One of the features in that that is you can access member variables without using the Set/Get functions.