Adding insight through animation in augmented reality

Most of the virtual world systems that have been so well publicized over the past ten years use opaque head mounted displays that block off the wearer from the surrounding real world, effectively immersing her within a synthesized environment. These systems hold tremendous promise for certain applications ranging from fantasy games to scientific research. In contrast, we believe that the most powerful and commonplace virtual worlds of the future will not replace the real world, but will rather augment it with additional information. This approach is called augmented reality and was pioneered by Ivan Sutherland, who, over a quarter century ago, developed the first see-through head mounted display (I. Sutherland, 1968). When completed, his system presented graphics to the user on a pair of stereo displays, worn on the user´s head. The image produced by the displays was combined with the user´s view of the world using mirror beam splitters. A 3D tracking system determined the position and orientation of the user´s head. This enabled the system to change the view, based on the direction in which the wearer was looking