Re: papervision camera formula (was: screen space to 3D space...)
Quoting from the 1.5 docs...
Camera3D () constructor
public function Camera3D(target:DisplayObject3D = null, zoom:Number = 2, focus:Number = 100, initObject:Object = null)
ZOOM:Number (default = 2) — This value is a positive number representing the distance of the observer from the front clipping plane, which is the closest any object can be to the camera. Use it in conjunction with ZOOM.
Huh?