Abstract: Motion sketching is an approach for creating realistic rigid-body motion. In this approach, an animator sketches how objects should move and the system computes a physically plausible motion that best fits the sketch. The sketch is specified with a mouse-based interface or with hand-gestures, which move instrumented objects in the real world to act out the desired behaviors. The sketches may be imprecise, may be physically infeasible, or may have incorrect timing. A multiple-shooting optimization estimates the parameters of a rigid-body simulation needed to simulate an animation that matches the sketch with physically plausible timing and motion. This technique applies to physical simulations of multiple colliding rigid bodies possibly connected with joints in a tree (open-loop) topology.