[vtkusers] Renderer::AddActor() with a subclass of vtkActor

[vtk at stmoser.ch]

Hi

I'm writing a tool that handles landmarks. I have subclassed 'vtkActor'
and added a couple of data fields. While the renderer (vtkRenderer) is
running I add can add vtkActors to the renderer and they appear in the
scene. If I use my subclassed actors, none of them appear. I'm creating
the actors 'from scratch' (points and polygons) and the only difference
is the object type. The subclassed actors do appear in the renderer's
actors list provided by GetActors().
Does anybody have an idea why this is?

Thanks, Stephan