%0 Journal Article
%T The art to keep in touch: The 'good use' of Lagrange multipliers
%A Antoine Jonquet
%A Olivier Nocent
%A Yannick Remion
%J Journal of Virtual Reality and Broadcasting
%D 2008
%I University of Applied Sciences Dusseldorf
%X Physically-based modeling for computer animation allows to produce more realistic motions in less time without requiring the expertise of skilled animators. But, a computer animation is not only a numerical simulation based on classical mechanics since it follows a precise story-line. One common way to define aims in an animation is to add geometric constraints. There are several methods to manage these constraints within a physically-based framework. In this paper, we present an algorithm for constraints handling based on Lagrange multipliers. After few remarks on the equations of motion that we use, we present a first algorithm proposed by Platt. We show with a simple example that this method is not reliable. Our contribution consists in improving this algorithm to provide an efficient and robust method to handle simultaneous active constraints.
%K Physically-based animation
%K constraints
%K contact simulation
%U https://www.jvrb.org/past-issues/4.2007/1276