What is Virtual Reality and how it works?
Virtual reality or virtual realities (VR), also known as immersive multimedia or computer-simulated reality, is a computer technology that replicates an environment, real or imagined, and simulates a user’s physical presence and environment to allow for user interaction. Virtual realities artificially create sensory experience, which can include sight, touch, hearing, and smell.
In a virtual reality environment, a user experiences immersion, or the feeling of being inside and a part of that world. He is also able to interact with his environment in meaningful ways. The combination of a sense of immersion and interactivity is called telepresence. Computer scientist Jonathan Steuer defined it as “the extent to which one feels present in the mediated environment, rather than in the immediate physical environment.” In other words, an effective VR experience causes you to become unaware of your real surroundings and focus on your existence inside the virtual environment.
Today, most VR systems are powered by normal personal computers. PCs are sophisticated enough to develop and run the software necessary to create virtual environments. Graphics are usually handled by powerful graphics cards originally designed with the video gaming community in mind. The same video card that lets you play World of Warcraft is probably powering the graphics for an advanced virtual environment.
VR systems need a way to display images to a user. Many systems use HMDs, which are headsets that contain two monitors, one for each eye. The images create a stereoscopic effect, giving the illusion of depth. Early HMDs used cathode ray tube (CRT) monitors, which were bulky but provided good resolution and quality, or liquid crystal display (LCD) monitors, which were much cheaper but were unable to compete with the quality of CRT displays. Today, LCD displays are much more advanced, with improved resolution and color saturation, and have become more common than CRT monitors.
Other VE systems project images on the walls, floor and ceiling of a room and are called Cave Automatic Virtual Environments (CAVE).
The big challenges in the field of virtual reality are developing better tracking systems, finding more natural ways to allow users to interact within a virtual environment and decreasing the time it takes to build virtual spaces. While there are a few tracking system companies that have been around since the earliest days of virtual reality, most companies are small and don’t last very long. Likewise, there aren’t many companies that are working on input devices specifically for VR applications. Most VR developers have to rely on and adapt technology originally meant for another discipline, and they have to hope that the company producing the technology stays in business. As for creating virtual worlds, it can take a long time to create a convincing virtual environment – the more realistic the environment, the longer it takes to make it. It could take a team of programmers more than a year to duplicate a real room accurately in virtual space.
Another challenge for VR system developers is creating a system that avoids bad ergonomics. Many systems rely on hardware that encumbers a user or limits his options through physical tethers. Without well-designed hardware, a user could have trouble with his sense of balance or inertia with a decrease in the sense of telepresence, or he could experience cybersickness, with symptoms that can include disorientation and nausea. Not all users seem to be at risk for cybersickness – some people can explore a virtual environment for hours with no ill effects, while others may feel queasy after just a few minutes.