This article presents a model for handling multi-resolution animation of complex deformable models. An octree-based animation and algorithmic tools are introduced to provide real-time interaction on complex objects. Some efficient collision detection scheme is also described for deformable models. A method is also presented for time-guaranteed mechanical simulation: It allows an automatic tuning of the octree resolution to match some external performance constraints, such as a pre-defined CPU consumption limit. Copyright © 2005 John Wiley & Sons, Ltd.