Like the Nintendo Wii game controller, the Motus Darwin lets video gamers control digital characters using physical gestures; unlike the Wii, it doesn't determine its position by triangulating with an infrared emitter fastened to the television. Instead, it measures gravitational forces and its own orientation with respect to magnetic north. So it doesn't get confused if its line of sight to the emitter is broken--by obstacles, or by gestures that yank it out of range.

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