1. In a computer-assisted animation system, a method for generating inbetween frames, wherein an inbetween frame is an image within an animation sequence that is to be displayed in sequence between two key frames drawn by an artist, and wherein the inbetween frames are to be initially at least partly computer generated, the method comprising: receiving a set of at least two key frames, include a first key frame that is to precede an inbetween frame set comprising at least one generated inbetween frame in the animation sequence and a second key frame that is to follow the inbetween frame set in the animation sequence; analyzing elements of the set of key frames to identify strokes in the images represented by the set of key frames, wherein a stroke is an image feature that is representable, in part, by a continuous curve segment with endpoints and zero or more additional sample points on the curve segment that has associated therewith an associated thickness, wherein a result of analyzing is the generation of a stored list of strokes; determining corresponding stroke pairs, a stroke pair comprising a first stroke of a first key frame of the set of key frames and a second stroke of a second key frame of the set of key frames; for each of a plurality of the corresponding stroke pairs, computing a continuous stroke motion for moving the endpoints of the first stroke of the stroke pair in the first key frame to the position of the endpoints of the second stroke in the second key frame, wherein the continuous stroke motion is defined by motions of the endpoints of the first stroke and the endpoints of the second stroke; for each of a plurality of mutual endpoints, wherein a mutual endpoint is an endpoint of two or more strokes in the first key frame and/or second key frame, adjusting the continuous stroke motion of the meeting strokes such that the adjustment results in the continuous stroke motion coinciding, or at least coinciding within a margin of error, at the mutual endpoint such that the mutual endpoint would follow the same path, within a margin of error, regardless of which of the mutual endpoint's stroke's continuous stroke motion is used; determining an animation time for a desired inbetween frame relative to the animation times of the first key frame and the second key frame; determining a location of endpoints given the animation time of the desired inbetween frame and continuous stroke motion; automatically generating strokes of the desired inbetween frame from at least the determined endpoint locations; and storing the automatically generated strokes in a form that allows for later electronic editing of the desired inbetween frame.