One method by which virtual reality can be realized is simulation-based virtual reality. Driving simulators, for example, give the driver on board the impression of actually driving an actual vehicle by predicting vehicular motion caused by driver input and feeding back corresponding visual, motion and audio cues to the driver.
With avatar image-based virtual reality, people can join the virtual environment in the form of real video as well as an avatar. One can participate in the 3D distributed virtual environment as form of either a conventional avatar or a real video. A user can select own type of participation based on the system capability.
In projector-based virtual reality, modeling of the real environment plays a vital role in various virtual reality applications, such as robot navigation, construction modeling, and airplane simulation. Image-based virtual reality systems have been gaining popularity in computer graphics and computer vision communities. In generating realistic models, it is essential to accurately register acquired 3D data; usually, a camera is used for modeling small objects at a short distance.

License information: CC BY-SA 3.0
MPAA: G
Go to source: https://en.wikipedia.org/wiki/Virtual_reality