Abstract: We present an object-centric formulation for parallel rigid body simulation that supports variable length integration time steps through rollbacks. We combine our object-centric simulation framework with a novel spatiotemporal data structure to reduce global synchronization and achieve interactive, real-time simulations which scale across many CPU cores. Additionally, we provide proofs that both our proposed data structure and our object-centric formulation are deadlock-free. We implement our approach with the functional programming language Erlang, and test the performance and scalability of our method over several scenarios consisting of hundreds of interacting objects.