To
move quickly around the scene, press and hold down the Alt key.
Use the left mouse button to rotate, the middle mouse button to
pan, and the right mouse button to zoom.
Press the ] key to orbit around a
center of interest (this is the default navigation mode).
Press the ] key to walk around objects
in discrete steps using the mouse buttons and arrow keys.
To set a new point of interest, hold
down the Ctrl+Alt keys
and click. Further movement is around that point.