Augmented Reality applications combine virtual objects with a 3-D real environment in real time (Milgram and Kishino 1994; Azuma 1997). Virtual and real objects appear together in a real time system in a way that the user sees the real world and the virtual objects superimposed with the real objects. The user’s perception of the real world is enhanced and the user interacts in a more natural way. Virtual objects can be used to display additional information about the real world that is not directly perceived.