Virtual Reality: Know-What, Know-How and Know-Why

Virtual Reality (VR), sometimes called Virtual Environments (VE) has drawn significant attention in the last few years. Extensive media coverage causes this interest to grow rapidly.

What is Virtual Reality?

Virtual reality (VR) is a technology which allows you to interact with a computer-simulated environment, be it a real or imagined one. It refers to immersive, interactive, multi-sensory, viewer-centred, three-dimensional computer generated environments and the combination of technologies required to build these environments. There are many terms used for virtual reality in computer community such as Synthetic Experience, Virtual Worlds, Artificial Worlds or Artificial Reality, just to name a few.

Most current virtual realities are displayed either on a computer monitor, a projector screen, or with a virtual reality headset or head mounted display (HMD). HMDs typically take the form of head-mounted goggles with a screen in front of the eyes.


How does Virtual Reality work?

The idea behind Virtual Reality is to deliver a sense of being there by giving at least the eye what it would have received if it were there and, more important to have the image change instantly as the point of view is changed. The perception of spatial reality is driven by various visual cues, like relative size, brightness and angular movement. One of the strongest is perspective, which is particularly powerful in its binocular form in that the right and left eyes see different images. Fusing these images into one 3D perception is the basis of stereovision.

The perception of depth provided by each eye seeing a slightly different image, eye parallax, is most effective for objects very near you. Objects farther away essentially cast the same image on each eye. The typical dress code for VR is a helmet with goggle-like displays, one for each eye. Each display delivers a slightly different perspective image of what you would see if you were there. As you move your head, the image rapidly updates so that you feel you are making these changes by moving your head (versus the computer following your movement, which it is). You feel you are the cause not the effect.

The components necessary for building and experiencing VR are divided into two main components: the hardware components and the software components. The hardware components include computer workstation, sensory displays, process acceleration cards, tracking systems and input devices (joystick, keyboard, voice recognition, instrumented glove, etc). The software components include 3D modelling software, digital sound editing software and VR simulation software.

Some of the sensory displays are Head mounted displays (HMDs), Binocular Omni-Oriented monitor, etc.

Head mounted displays (HMDs)

HMDs place a screen in front of each of the viewer’s eyes always. The view, the segment of the virtual environment generated and displayed, is controlled by orientation sensors mounted on the “helmet”. Head movement is recognized by the

computer, and a new perspective of the scene is generated. In most cases, a set of optical lens and mirrors are used to enlarge the view to fill the field of view and to direct the scene to the eyes.

Binocular Omni-Oriented monitor (BOOM)

The BOOM is mounted on a jointed mechanical arm with tracking sensors located at the joints. A counterbalance is used to stabilize the monitor, so that when the user releases the monitor, it remains in place. To view the virtual environment, the user must take hold of the monitor and put her face up to it. The computer will generate an appropriate scene based on the position and orientation of the joints on the mechanical arm.

Why have Virtual Reality?

What makes the development of virtual reality beneficial? There has been increasing interest in the potential impact of VR. One of the beneficial uses of VR occurs when visualization, manipulation, and interaction with information are critical for its understanding; it is, in fact, its capacity for allowing learners to display and interact with information and environment that some believe is virtual reality’s greatest advantage.

Virtual Reality has impact in heritage and archaeology, mass media, fiction books, television, motion pictures, music videos, games, fine arts, marketing, health care, therapeutic uses, real estates and others numerous to mention.

Features of Virtual Reality

The quality of any VR system is determined by mainly 3 I’s i.e., immersion, interaction and imagination.

Immersion, otherwise known as presence, is the feeling of being present or being a part of the computer-generated world. This is because of the stimulation of the human senses (visual, aural, haptic, smell etc.) by the system.

Interaction is a means of communicating with the system, but unlike the traditional Human-Computer Interaction which uses 1-2 dimensional (1D, 2D) means, like mouse, keyboard or keypad, interaction in VR is usually through 3 dimensional (3D) means, like space ball and head-mounted device (HMD). Some features for interaction in VR systems are effectiveness, real time reaction and human participation.

Imagination can be the thought of the system designer to execute a goal. With the applicability of components of the VR system for complex problem solving in diverse fields, its use as a more efficient and effective means of expressing ideas than the traditional 2D drawing or text explanation, cannot be argued.