filename     : Zos18a.pdf
entry        : inproceedings
conference   : SIGGRAPH 2018, Vancouver, Canada, August 12th - 16th, 2018
pages        : 59:1-59:12
year         : 2018
month        : August
title        : An Empirical Rig for Jaw Animation
subtitle     :
author       : Gaspard Zoss, Derek Bradley, Pascal Bérard, Thabo Beeler
booktitle    : ACM Transactions on Graphics (TOG) - SIGGRAPH 2018 Conference Proceedings
ISSN/ISBN    : 0730-0301
editor       : ACM New York, NY, USA 
publisher    : Association for Computing Machinery
publ.place   : New York, NY, USA
volume       : 37
issue        : 4
language     : English
keywords     : Jaw Rig, Data Driven Animation, Jaw Animation, Facial Animation, Motion Capture, Acquisition
abstract     : In computer graphics the motion of the jaw is commonly modelled by updown and left-right rotation around a fixed pivot plus a forward-backward translation, yielding a three-dimensional rig that is highly suited for intuitive artistic control. The anatomical motion of the jaw is, however, much more complex since the joints that connect the jaw to the skull exhibit both rotational and translational components. In reality, the jaw does not move in a three-dimensional subspace but on a constrained manifold in six dimensions. We analyze this manifold in the context of computer animation and show how the manifold can be parameterized with three degrees of freedom, providing a novel jaw rig that preserves the intuitive control while providing more accurate jaw positioning. The chosen parameterization furthermore places anatomically correct limits on the motion, preventing the rig from entering physiologically infeasible poses. Our new jaw rig is empirically designed from accurate capture data, and we provide a simple method to retarget the rig to new characters, both human and fantasy.