1. A method for simulating relative motion of objects, the method comprising: receiving, at one or more computer systems, an animation sequence indicative of motion of a first object; selectively manipulating during a portion of the animation sequence, with one or more processors associated with the one or more computer systems, motion of a second object determined from a computer simulation of the second object according to a model that defines physics of the simulation in response to a compensation force configured to act on the second object during the portion of the animation sequence to be inconsistent with the model when motion of the first object during the portion of the animation sequence satisfies one or more predetermined conditions, the compensation force being separate from any forces determined to be acting on the second object by the model; and generating, with the one or more processors associated with the one or more computer systems, information indicative of the manipulated motion of the second object.