Patent ID: 7317457

Claim:
A computer readable medium storing instructions for causing a computer to process image data and produce a modified curve representing animation data, by performing the steps of: receiving an input specifying a modification to a first keyframe indicator, the first keyframe indicator including a first handle extending from the first keyframe indicator to a first control point partially defining a first curve; identifying a second keyframe indicator connected to the first keyframe indicator by the first curve, the second keyframe indicator including a second handle extending from the second keyframe indicator to a second control point partially defining the first curve; adjusting the first handle and the second handle based on the modification to produce a modified first handle and a modified second handle, wherein the adjustments to the first handle and to the second handle, respectively, comprise calculating a modified slope for the first handle equal to a tangent of the first handle scaled by negative one and calculating a modified slope for the second handle equal to a tangent of the second handle; and computing a modified first curve between the first keyframe indicator and the second keyframe indicator based on the modified first handle and the modified second handle, wherein the modified first curve does not overshoot the second keyframe indicator.