Synthesizing walking motions independent of limb length

Abstract

Motion capture greatly improved the quality of animations, but the body proportions of the actor are not always equal to those of the virtual character. This paper presents a method to change the leg length of a character during an animation while preserving the motion capture data and without leaving visual artifacts. This results in a system capable of following a given path on a 2D plane in a 3D environment using a motion graph as input, while the legs of the character change. In order to plan the path with the change in leg length, a formula is introduced that estimates the preferred walking speed of a person solely depending on leg length. This formula is based on research from the ?eld of biomechanics. When the resulting speed is applied to the character foot skating is introduced. This is removed using timewarp and a method called Morphology Independent Representation for constraint solving. The overall motion is smoothened using linear interpolation. The system is able to make a character smoothly follow a given path while the length of the legs are changed.