Thumb modelling for the generation of sign language

Abstract

We present a simple kinematic model of the thumb for the animation of virtual characters. The animation is made through a purely kinematic approach, thus requires very precise limitations on the rotations of the thumb to be realistic. The thumb is made opposable thanks to the addition of two bones simulating the carpo-metacarpal complex. The bones are laid out to build a virtual axis of rotation allowing the thumb to move in the opposed position. The model is then evaluated by generating 22 static hand-shapes of Sign Language and compared to previous work in animation. © 2012 Springer-Verlag Berlin Heidelberg.