InfrActables: Multi-user tracking system for interactive surfaces

We present InfrActables, a wireless technology for human computer interaction devices. It allows multiple users to interact simultaneously on back-projection displays. It recognizes each device's position, orientation, and identification, but also enables the tools to communicate their states to the application that the user interacts with. This makes it possible to build complex interaction devices for direct manipulation with buttons, sliders, and other input capabilities. The technology was developed for a computer-supported environment, allowing multiple users to interact simultaneously on a surface using multiple styli and other user input devices. The principle of operation is not limited to two-dimensional surfaces, three-dimensional user input devices can also profit from its advantages.