Ballistic Shadow Art

Abstract

We present a framework for generating animated shadow art using occluders under ballistic motion. We apply a stochastic optimization to find the parameters of a multi-body physics simulation that produce a desired shadow at a specific instant in time. We perform simulations across many different initial conditions, applying a set of carefully crafted energy functions to evaluate the motion trajectory and multi-body shadows. We select the optimal parameters, resulting in a ballistics simulation that produces ephemeral shadow art. Users can design physically-plausible dynamic artwork that would be extremely challenging if even possible to achieve manually. We present and analyze number of compelling examples.