Collision sequences are commonly used in games and entertainment to add drama and excitement. Authoring even two body collisions in real world can be difficult as one has to get timing and the object trajectories to be correctly synchronized. After trial-and-error iterations, when objects can actually be made to collide, then they are difficult to acquire in 3D. In contrast, synthetically generating plausible collisions is difficult as it requires adjusting different collision parameters (e.g., object mass ratio, coefficient of restitution, etc.) and appropriate initial parameters. We present SMASH to directly `read off' appropriate collision parameters simply based on input video recordings. Specifically, we describe how to use laws of rigid body collision to regularize the problem of lifting 2D annotated poses to 3D reconstruction of collision sequences. The reconstructed sequences can then be modified and combined to easily author novel and plausible collision sequences. We demonstrate the system on various complex collision sequences.
['Aron Monszpart', 'Nils Thuerey', 'Niloy J. Mitra']
SMASH: Data-driven Reconstruction of Physically Valid Collisions