The zoom, rotate, pan, and other mouse actions available for manipulating the
                viewer in user interface mode perform identical functions in the viewer in line
                interface mode. In addition to this, hotkeys can be used to manipulate other aspects
                of the viewer. For a full list of all the hotkeys available click in the viewer to
                make it the active window and select the ? icon. To execute
                a hotkey command, click once in the viewer (or on the object, as some functions are
                object-specific) and type the command.