Vijay Ratna Kumar Blog

Introduction

Virtual Reality (VR) is a technology that provides one with the sensations and the control of perspective so than one experiences the illusion of being in the presence of an object, within a situation or surrounded by a place. The illusion seems more real if different kinds of sensations are provided to the user. Today VR relies on audio and video technologies augmented by a computer interface that reads the movement of the participant’s body. These act as triggers that change the direction of sounds and the perspective of sights so that one see and hears an artificial world that appears to respond to one’s body movement just as the real world does. It can be defined as follows. VR refers to a computer based application which provides a human computer interface such that the computer and its devices create a sensory environment which is dynamically controlled by the actions of the individual so that the environment appears real to the user. VR implies interactivity between the user and the system, secondly, the fundamental principle lies in the fact that the computer creates a sensory environment which is intended to appear real. This artificial environment is usually referred to as the “virtual world”. The term virtual reality was coined by Jaron Lanier in 1989. Lanier is one of the pioneers of the field, founding the company VPL Research (from Virtual Programming Languages) which built some of the first systems in the 1980s.

Forms of Virtual Reality

            In general, there are three form of VR: through-the-window, immersive and second person.

           

           Through-the-window

The most common type of VR is called through-the window VR is applied extensively in games and movie theatres. It allows a participant to look into the virtual world from a seat in the real world. The “window” the user looks through may be as small as a home computer monitor or as large as a movie screen. Although, movie theatres allow for no true interactivity, computer games allow some interactivity between the user and the virtual scene. The images are always real-world video photographed with a camera. In some cases the seats move and vibrate in response to images portrayed, e.g. roller coasters. Any participant who looks way from the screen during the experience “falls out” of the world and back into the real world. But the sensations of speed and rapid movement whil looking at that world can be convincing.

            

            Immersive

The second form of VR is called immersive VR and is done with a hear-mounted gear. Here, the scene is synthetic and created by software, not filmed. The head-mounted gear allows the participant to enter and become immersed in the virtual world. The principle difference between immersive and through-the-window types is that in the former the user is in an immersive environment and can turn around, look behind and something of the virtual world. An immersive virtual world is genuinely three-dimensional and inclusive. Usually, immersive worlds are also interactive- the participant decided where to travel. This may even include flying through the ceilings and walls. Sometimes objects in the virtual world may be changed as a response of something the used does. To make this possible, the head mounted gear is fitted with tracking devices that records the movements of the used and send the information to the computer. Based on the information, the software changes the scene in front of the user.

            

            Second Person

IT uses a camera to capture the image of a participant and insert in inot the virtual world. Users then watch their own images on a monitor interacting with objects in the virtual world. In most applications of this type, the insertion of the participant’s image is done by Chroma-Keying. This sometimes creates highlights around the participant or image-resolution differences between the participant and the background. Also, it often takes some amount of practice to co-relate one’s own body movements with what is happening on the screen.

           

Web Resources:

            Virtual reality – http://enwikipedia.org/wiki/Virtual_reality

            What real about virtual reality – http://wwwcs.unc.edu/-brooks/WhatsReal.pdf

            Touch in virtual environments – http://www.roblesdelatorre.com/gabriel/GR-IEEE-MM-2006.pdf

            Haptic interfaces- http://www.roblesdelatorre.com/abriel/VH-OA-MC-DG-GR-04.pdf

            Virtual Reality News – http://vroot.org