1. In this paper, we introduce a method for representing piles of objects in large multibody simulations.
2. Object piling and stacking is computationally expensive, so a model that can do it quickly with user control would be nice.
3. Model piles as layers of objects. Then add a criteria for putting objects asleep so they are no longer simulated (improving performance and adding the user control).
4. This paper lets you simulate piling/stacking objects with a moderate improvement in performance and allows for some user control of how the pile turns out.
5. Video: http://www.youtube.com/watch?v=18Rtj4A0P5g&feature=player_embedded