For 25 years, the field of robotics has been bedeviled by a fundamental problem: If a robot is to move through the world, it needs to be able to create a map of its environment and understand its place within it...

On November 4, a solution was discovered—in a videogame. That’s the day Microsoft released the Kinect for Xbox 360, a $150 add-on that allows players to direct the action in a game simply by moving their bodies. Most of the world focused on the controller-free interface, but roboticists saw something else entirely: an affordable, lightweight camera that could capture 3-D images in real time.