Mouse problem

[steve]

Hi,thank you for all of your previous help.
The thing that I am trying to do is make a navigation system (as in Kaydara from Alias). So far I can zoom in and out, move up and down, and left and right. All that is left is the rotation part. I want to be able to rotate around the center of the visible scene.
I know how to get the radius of this imaginary circle (e.g. over view.get(viz.HEAD_POS)... Phytagoras...) but with view.get(viz.HEAD_POS) I only get the position towards the 0,0,0 point, but not to the center of the visible scene as seen by the user. How can I get that?

Thanks again for your help
--Steve