Augmented Reality (AR) has come a long way since its inceptions in the early nineties. According to Milgram and Kishino(1994), AR can be defined as any case in which an otherwise real environment is “augmented” by means of virtual (computer graphic) objects. Compared to Virtual Reality (VR) in which the users while immersed cannot see the real world, AR allows the user to see the real world with virtual objects superimposed upon or composited with the real world (Azuma, 1997, p. 2).
In addition, Paul Milgram and Fumio Kishino defined Milgram’s Reality-Virtuality Continuum in 1994 (Figure 1). They describe a continuum that spans from the real environment to a pure virtual environment and in-between there are Augmented Reality (closer to the real environment) and Augmented Virtuality (is closer to the virtual environment).
So what AR allows us to do is to see virtual objects in a real world environment with the aid of camera and some sort of display device (monitor or head mounted display).
History of Augmented Reality
The term augmented reality is believed to have been coined by Tom Caudell, a Boeing researcher around 1992. However, AR was around for much longer before 1992. In 1957, cinematographer Morton Heilig created a simulator with visuals, audio, vibrations and smell. In 1966, Ivan Sutherland invented a head mounted display which gave us a peak into the virtual world. A three minute video (Figure 3) produced by Rocketboom nicely summarizes the history of AR.
Another educational video done by Explainers, summarizes AR in three minutes (Figure 4).