[vtkusers] Assemblies and vtkInteractor pickers

[Eugene Kim]

Hi everyone,

 	I have a question on the default picker in the 
vtkRenderWindowInteractor and thus classes like the 
vtkInteractorStyleTrackballActor.  I know how to tailor a vtkPropPicker to 
return to me not only assemblies but their respective paths, allowing me 
to tease out the inidividual actor that was picked on screen, but I am not 
able to do this with the pickers provided in the Renderwindowinteractor. 
This seems to be because of the explicit GetViewProp() call in the C++ 
code, (that exists in vtkInteractorStyleTrackballActor).  This results in 
the picking of the top-level assembly only, and thus I cannot move 
indiviudal actors.
 	Does anyone know how to fine-tune the behavior of the picker?  Is 
it absolutely necessary to subclass vtkInteractorStyle or is there a 
workaround?

Thanks,
Eugene