[vtkusers] xxxxxSPAMxxxxx TrackBall Actor Question

[alex]

Hi

I have 3 objects like sphere,cone,box. I want rotate only some selected 
object .

I looked at vtkInteractorStyleTrackballActor is doing my job but i want to 
customize some events like i want to pick only some objects not all.  For 
example i wish to rotate only shpere not box and cone.

So how to do this job ?

Alex