Overlaying computer generated information ontop of the real world in meaningful ways.
Explanation of the Technology
Pattern matching using the real world environment. Makes for much more realistic interaction between AR elements and the real world. Harder to do.
Requires the use of a fiducial, or marker, that the computer recognizes as a unique pattern and overlays data. Covering the marker breaks the computers ability to overlay until it is uncovered. Some applications such as ARToolkit+ and others use an array of multiple markers to provide redundancy. Very easy to implement and has the most homebrew work available.
Using a compass for direction, current GPS coordinates, and the GPS coordinates of a place, the computer can overlay information rather accurately in larger areas. Doesn't work for areas smaller than about 3 meters however due to the resolution of GPS. Gaining heavy popularity on smart phones due to their ubiquity of having GPS and digital compasses.
- Atomic Web Authoring Tool