Virtual Reality : How It Works

12 Pages 3119 Words

in itself, is not a very new idea, but the new twist is trying to generate completely new images in real- time. In 1933, Sir Charles Wheatstone invented the first stereoscope with the same basic principle being used in today's head-mounted displays. Presenting different views to each eye gives the illusion of three dimensions. The glasses that are used today work by using what is called an "electronic shutter". The lenses of the glasses interleave the left-eye and right-eye views every thirtieth of a second. The shutters selectively block and admit views of the screen in sync with the interleaving, allowing the proper views to go into each eye. The problem with this method though is that you have to wear special glasses. Most VR researchers use complicated headsets, but it is possible to create stereoscopic three-dimensional images without them. One such way is through the use of lenticular lenses. These lenses, known since Herman Ives experimented with them in 1930, allow one to take two images, cut them into thin vertical slices and interleave them in precise order (also called multiplexing) and put cylinder shaped lenses in front of them so that when you look into them directly, the images correspond with each eye. This illusion of depth is based on what is called binocular parallax. Another problem that is solved is that which occurs when one turns their head. Nearby objects appear to move more than distant objects. This is called motion parallax. Lenticular screens can show users the proper stereo images when moving their heads well when a head- motion sensor is used to adjust the effect. Sound is another important part of daily life, and thus must be simulated well in order to create artificial reality. Many scientists including Dr. Elizabeth Wenzel, a researcher at NASA, are convinced the 3D audio will be useful for scientific visualization and space applications in the ways the 3D video is somewhat limited. She has come up with ...