Scarica (PDF – 6.19 MB)

2 Background
2.1 Augmented reality
Augmented reality (AR) is a term for a live, direct or indirect view of
a physical real-world environment whose elements are augmented by
virtual computer-generated imagery [33].
Figure 2: Example of AR: a graphical model is rendered on a real fiducial marker
[34].
Many definitions have been proposed in literature for AR. Azuma
et al. [14] define AR as a variant of Virtual Reality (VR). VR tech-
nologies completely immerse a user inside a synthetic environment. In
contrast, AR allows the user to see the real world, with virtual ob-
jects superimposed upon or composited with the real world. Therefore,
AR supplements reality, rather than completely replacing it. Ideally, it
would appear to the user that the virtual and real objects coexisted in
the same space. Azuma et al. [14] states that the main requirements
for a visualization interface to fall within the AR category are:
• to combine real and virtual;
• to be interactive in real-time;
7