An input device for a computer graphics system provides a plurality of wheels
that control movement of a virtual camera. The input device can be readily used
by professional camerman without knowledge or training on CG animation software
tools. The input device comprises a housing having at least one wheel operatively
coupled to at least one outer surface of the housing. The at least one wheel has
an axially coupled shaft that is driven rotationally by manipulation of the wheel.
Circuitry contained within the housing and operatively coupled to the shaft generates
a control signal corresponding to rotational motion of the at least one wheel.
The control signal is thereby provided to the animation processor to control the
virtual camera. In a preferred embodiment of the invention, the at least one wheel
further comprises a plurality of wheels with each such wheel corresponding to a
different range of motion of the virtual camera, including a first wheel corresponding
to panning motion of the virtual camera, a second wheel corresponding to tilting
motion of the virtual camera, and a third wheel corresponding to rolling motion
of the virtual camera. The circuitry further includes an angle encoder operatively
coupled to the shaft and a control circuit adapted to convert the control signal
into a data stream having a format readable by the animation processor. The input
device may also include at least one speed control adapted to change effective
resolution of the at least one wheel, and at least one direction control adapted
to change effective direction of the at least one wheel.