What is augmented reality?
Augemented reality is meshing digital information into a real-world environment where that digital information is presented to the user visually. An AR application requires a tracking element, a registration element, and a visualization element. AR can be divided into 2 groups: mobile and fixed. Mobile AR allows the user to move about freely in their environment with a mobile device. Fixed AR requires that the user stay in a stationary position where ever the equipment is located. Tom Caudell and David Mizell, from Boeing, are credited with coming up with the term "augmented reality" in 1990. [22, 26, 30] A researcher in AR, Ronald Azuma, provides a definition of AR that requires the following elements: it is a combination of real and virtual, users are able to interact in realtime, and it is in 3D. Another researcher, Gene Becker, has a more detailed definition of AR being the following: a technology, an area of research, innovation in future computing, up-and-coming commercial industry, and a new platform for creative expression. [26]
Most AR applications are single user, but that's not the only option. Tangible AR interfaces allow users to use haptic, or sense of touch, to provide information to the AR application. Collaborative AR interfaces allow multiple users to interact using multiple displays. Hybrid AR interfaces allow the combination of serveral differnt displays for user interaction. Multimodal AR interfaces allow users to combine multiple ways of communicating with the AR application, even using speech, touch, hand gestures, or even looking at a certain location. [26]