Catching a Real Ball in Virtual Reality

We present a system enabling users to accurately catch a real ball while immersed in a virtual reality environment. We examine three visualizations: rendering a matching virtual ball, the predicted trajectory of the ball, and a target catching point lying on the predicted trajectory. In our demonstration system, we track the projectile motion of a ball as it is being tossed between users. Using Unscented Kalman Filtering, we generate predictive estimates of the ball's motion as it approaches the catcher. The predictive assistance visualizations effectively increases the user's senses but can also alter the user's strategy in catching.