1. A method of constructing a summary spline curve from a plurality of animation spline curves, the method comprising: receiving the plurality of animation spline curves, each animation spline curve associated with a plurality of control points, each animation spline curve representing a characteristic of an object at a plurality of frames in a computer animation; determining a combined set of control points comprising control points associated with the plurality of animation spline curves; for each pair of neighboring control points in the combined set of control points: for each animation spline curve in the plurality of animation spline curves: determining a spline curve segment between the neighboring control points; and normalizing the spline curve segment to determine a normalized spline curve segment for the animation spline curve; and averaging the normalized spline curve segments for each of the animation spline curves to determine a summary spline curve segment for the pair of neighboring control points; and combining the summary spline curve segments for each pair of neighboring control points to determine a summary spline curve.