Patent ID: 7545378

Claim:
A computer-readable storage medium including instructions adapted to direct a computer to perform an operation, the operation comprising: receiving a first foot position of a foot model; defining a contact point on the foot model based on the first foot position, wherein the contact point intersects a ground plane at a first point on the ground plane; receiving a foot roll parameter for the foot model, wherein the foot roll parameter specifies a desired foot roll angle between the ground plane and at least a portion of the foot model; defining a foot model transformation adapted to change a relative angle between at least the portion of the foot model and the ground plane to the desired foot roll angle; moving the foot model to a second foot position using a first application of the first foot model transformation to the foot model; and rotating at least the portion of the foot model at the second foot position using a second application of the first foot model transformation to at least the portion of the foot model, whereby the contact point on the rotated foot model at the second position intersects the ground plane at the first point on the ground plane.