[vtkusers] Writing two or more actors to the same vtp file

[Avi Sengupta]

I would like to serialize two or more vtkActors to the same .vtp file. I 
do not want to use a vtkPolyDataAppender as it does not allow me to have 
actor specific properties (color, opacity, etc.)
Is there a way that this can be done?

Thanks
Avi