About Viewing Models in Stereoscopic Scaled View
When you select the Scaled stereo type, Creo View adjusts the navigation options:
Flying and Zooming In
When you fly or zoom in to an object, Creo View positions the closest point of the relevant bounding box on the screen plane.
Zooming In with the Mouse Wheel
Since the stereoscopic view is calculated by positioning the closest point of the bounding box on the screen plane, when you zoom in to an object using the mouse wheel and pass the point mentioned above, Creo View moves this point accordingly.