To balance the artist’s desire for bounce during the walk cycle and control during extreme motion, we nonlinearly change........ from the current value to a maximum specified stiffness using a cubic Hermite blend function based upon the amount of longitudinal curl stretch. We compute the blend weight from the ratio of the total length of the current curve,..... , to the total length of the rest curve, ......... . By automatically adjusting the core stiffness and damping, we avoid the need for per-shot parameter tuning.