Supporting Multiplayer Online Ball Passing at a Distance with Multiple Sets of Kinect

We present Alone Together, a collaborative virtual ball playing environment augmented with three sets of Microsoft Kinect. The play environment fulfills a 'sport over the distance' them via the attempt to mimic the real world ball-passing exercise (or rehabilitation sessions) except that the players can be miles away from each other, and they interact without a physical ball. Moreover, our system allows each player to see the other two and their physical environment respectively, which is a combination of the physical world where players are situated and the virtual world where they play with each other. Kinect sensors are used to map players' action into a virtual world including the passing of the virtual ball.