[vtkusers] Check for actor in camera view

[JBK]

Hi VTK Users,

I am developing visualization software in which I am saving view 
information between uses of the program.  If the user loads in different 
data on a subsequent use of the software, the camera may be aiming at 
the wrong location in the space.

Is there a way to detect if there are any actors that are actually 
within view of the camera?  I would like to be able to intelligently 
detect if the camera's  viewing area contains the data that has been 
plotted and if not, automatically reaim it at the data.

The reason I don't want to just automatically reaim the camera each time 
is that the user may have a certain view from the last session that I 
would like to preserve between program sessions.  I know there are 
probably a lot of ways to do this from a computational standpoint but I 
would like to utilize a method from VTK if it actually exists.

Thanks,
Josh