Animation traditionally is done by hand-drawing or painting successive frame of an object, each slightly different than the proceeding frame. In computer animation, although the computer may be the one to draw the different frames, in most cases the artist will draw the beginning and ending frames and the computer will produce the drawings between the first and the last drawing. This is generally referred to as computer-assisted animation, because the computer is more of a helper than an originator.
In full computer animation, complex mathematical formulas are used to produce the final sequences of pictures.