In this chapter, we provided an introduction to the research field and practical occurrences of augmented reality. For a working definition, augmented reality relies on three key components: (1) the combination of virtual and real information, with the real world as the primary place of action and (2) interactive, real-time updates of (3) virtual information registered in 3D with the physical environment. Different technologies can be used to realize such a concept. The first part of this book provides an overview of technologies for displays (Chapter 2), tracking technologies (Chapters 3, 4, and 5) and graphics (Chapters 6 and 7). The second part of the book (Chapters 8 through 14) deals with interactive techniques.
We also presented a brief history of the field and then went on a whirlwind tour of AR application examples, with the goal of suggesting the enormous potential that AR holds as an interface metaphor to computing in the physical world (sometimes referred to as situated computing). While many specific application possibilities exist, such as AR for equipment maintenance or AR for surgery, one can also envision AR turning into a more general interface paradigm, redefining the overall browsing experience for computing in the physical world. Application examples from the domains of personal information display and navigation hint at that potential.
We concluded this chapter with a discussion of related fields. In doing so, we placed AR within the scope of Milgram’s mixed reality continuum and contrasted AR with Weiser’s concept of ubiquitous computing.