Abstract
Methods based on aerodynamics are developed to simulate and control the motion of objects in fluid flows. To simplify the physics for animation, the problem is broken down into two parts: a fluid flow regime and an objcct boundary regime. With tin's simplification one can approximate the realistic behaviour of objects moving in liquids or air. It also enables a simple way of designing and controlling animation sequences: from a set of flow primitives, an animator can design the spatial arrangement of flows, create Hows around obstacles and direct flow liming. Hie approach is fast, simple, and is easily fitted into simulators Thai model objects governed by classical mechanics. The methods arc applied to an animation that involves hundreds of flexible leaves be-ing blown by wind currents.