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Virtual Reality

Written By: 

Ashok Sharma

GoGo….Go…Roger FIRE in the hole!….Fire in the hole!!!….Two down…TWO DOWN…one more one more… YOU LOST!!!

What is Virtual Reality

While pressing the keys of your keyboard or keypad to convert the lost games to last moment victories the chances are you have encountered the virtual reality in your life. These games involve you with the characters or objects and with the amplification of the involvement, one feels a part of this virtual world. By using 3D imagery with a head mounted device (HMD) and high quality surrounding sound equipments, these games creates more involvement in the virtual world and consequently shut down the cues of real world. This is what called virtual reality, which has applications far beyond gaming.
 
What is Virtual Reality?
Virtual reality can be defined as an upcoming technology that makes users feel in a Virtual Environment (VE) by using computer hardware and software. It was originally conceived as a digitally created space which humans could access by donning special computer equipments. It enables people to deal with information more easily. VR provides a different way to see and experience information, one that is dynamic and immediate. For example, in a computer game, user’s joystick motions are tracked and the objects in the game are moved according to the joystick movements. In the same way a simulated, three-dimensional world is created around the user in which he/she could interact with objects, people, and environments. Typically three-dimensional life-sized images with support of audio devices are presented around the user and the perspective is modified in accordance with the user input (generally head or eye movements). Many devices along with the computers are used to create a virtual environment.
 
To enter in a VE, a user dons special gloves, earphones, and goggles, all of which send their output to the computer systems. The virtual environments are intended to replace the real world environment with the digital one and the human senses are immersed in the VE. Immersion is an experience of losing oneself in the VE and shutting out all cues from the physical world.  A Virtual Environment can be created on different extents depending on the computer based platform ranging from a cell phone screen to a desktop monitor or a fully Immersive Virtual Environment (IVE).
The tracking and rendering turns the whole process more immersive and interactive than the traditional media like televisions and video games. The user actions result in immediate and observable impact on the content of virtual environment. Following are the main components of a virtual environment:
1.      The visual displays that immerse the user in the virtual world and block out contradictory sensory impressions from the real world.
2.      The graphics rendering system that generates the ever changing images at 20 to 30 frames per second.
3.      A tracking system that continuously informs the position and orientation of the user’s movements.
4.      The database construction and maintenance system to build and maintain a detailed and realistic model of the virtual world.
5.      A sound system that can produce high quality directional sounds and simulated sound fields.
6.      Devices like tracked gloves with pushbuttons to enable users to specify their interactions with the virtual objects.
How VR works
A simple example of ‘Counter Strike’ game can give a thought as to how virtual reality works. The software program for the game is the major element which runs with the help of the computer system and the interfaced input output devices. Every Character and environment within the game behaves closely to reality as per the code written for them. The code facilitates characters and environment to interact with the other characters controlled by the input devices. The code is interpreted by the processor which handles the input – output devices accordingly. This is the simplest example of how VR works. The working of more immersive virtual reality environment is quite similar to working of the game besides the fact that a number of advanced input and output devices along with a high performance processor are added to increase the immersion. The processor executes the processes quickly according to the input given by the user and output is presented to the user in a way that user feels itself a part of the environment and its objects. The video below shows an example of more immersive virtual reality.
 
 
The 3D visualization component enables the user to see 3D scenarios by using a display methodology like a head mounted device. Typically the 3D images superimpose the real environment by using one of the display, screen based or projection based. The screen based virtual environment generally uses a high quality display screen in terms of resolution and color, or a head mounted device along with the sound system as output devices. A keyboard, microphone, head tracking sensors, finger trackers, gesture recognition system, a joystick or similar gears are used as input devices. When user moves the gear or joystick, make move of the head, or press any key on the keyboard, the objects of the screen are changes accordingly in a way that user feels if he/she is directly controlling the objects and environments on the screen. A high speed powerful processor processes the inputs. An Application Programming Interface (API) provides the interface to the input devices connected to the system as well as to standard devices like mouse and keyboard. The timings and relationship between input and output devices are so perfect that user feels an immersion with the virtual environment.

 

The other technique used to create a virtual environment is projection based, which is more immersive than the screen based method. The display images are projected on the multi screen spaces ranging from two to six screens. A six screen’s would make a better virtual environment. Both floor and ceiling uses a rear projection while the other four screens yield large surrounding views for both panning actions and looking down. Consequently objects inside the space could be walked around and virtual entreat to be touched.
 

Head Mounted Display & CAVE

VR Environments: Head Mounted Display
The most commonly used hardware equipment in virtual reality technology is HMD which render the virtual environment in front of eyes. A HMD provides full colorVR Environments: Head Mounted Display quality viewing with clear, vivid graphics and stunning imagery. The device can connect to any computer or video source via an SVGA or DVI connection. They have integrated headphones to deliver the full stereo surround sounds.
A typical Head Mounted Device incorporates two miniature display screens and an optical system that channels the images from screens to the eyes, presenting a stereo viewing of the virtual world.
 
A motion tracker continuously records the position and orientation of the user’s head and eyeballs, and allows the image generating computer to adjust the scene representation to the current view. Resultantly users are able to look around or walk through the surroundings of the virtual environment. The head orientation is generally tracked through a device, such as accelerometer which provides the feedback regarding the pitch, yaw and roll of the users head. To track the user’s movement in the physical space, optical or magnetic trackers are attached with the user to record the information about the X, Y and Z coordinates of the user’s position.
 
VR Environments: CAVE (Cave Automatic Virtual Environment)
CAVE, Cave Automatic virtual environment, is another immersive VE system projects images on the walls, floor and ceiling of a room. It generally uses multiple VR Environments: CAVE (Cave Automatic Virtual Environment)cameras and a projection screen in an enclosed room to make feel users that they are surrounded by a virtual environment. The more complex CAVEs uses hardware that creates a different sensory model that is beyond the physical stimuli, such as the auditory aspects of a virtual environment can be transmitted through headphones or speakers. The sound interacts with the brain three dimensionally enhancing the realism of the virtual environment experience. The sense of touch is also incorporated in the CAVEs by using sensory gloves and other haptic devices. Some haptic devices also allow users to exert a touch or grasp or replace a virtual object.
 
 

Applications

Applications
As Virtual Reality has gained traction in the real world, scientist and researchers have started to think about their use in various fields like medical science, gaming and education.
·         Medical Science - One of the most common uses of the virtual reality is in Virtual Reality Exposure Therapy (VRET) which treats the patients Virtual Reality in Medical Sciencesuffering from some specific anxiety or phobias. Patients are gradually introduced to the negative situations in a virtual environment until they become desensitized and are able to handle with their fear or anxiety. The diseases like acrophobia (the fear of heights), Agoraphobia (fear of spaces), Arachnophobia (social phobia) are treated using the VERT therapy. Virtual Environments (VEs) are also used to study the patient’s reactions and behaviors to high anxiety environments. Medical students, doctors and nurses are taught the basics of human anatomy as well as surgical procedures by creating 3D virtual models.
 
·         Education - Virtual Reality is used to train people working in widely diverse settings or professions, from fighter pilots to librarians.  The simulation of environmentsApplications of virtual reality in Education using sensory immersion has been proven an effective training method. Training in monitoring and verification of performance is as simple as simulating the normal and abnormal conditions within the workplace environment. Simulations can be distributed to centers to be used by the trainers or trainees, and new environments and conditions can be added easily. The use of virtual reality is also increasing in military, especially to train pilots by developing special flight simulators which provide pilots a safer and less expensive way to learn flying skills. Also Virtual simulations of conflict scenarios have been used to teach soldiers how to make quick and effective decisions under stressful circumstances.
An example of a simulation tool is ‘MaxwellWorld’, which is designed to help students understand the concepts of electrostatic fields. Generally students have trouble understanding the relationship of abstractions about electric fields to phenomenological dynamics. The MaxwellWorld enable learners to virtually experience scientifically accurate models of electric fields and make factors significant that are not noticeable in the real world like how forces at each point in space continually accelerate a test charge through 3D interactive imageries.
 
·         Gaming – Gaming is another industry where virtual reality technology is deployed and resultantly wApplications of virtual reality in gaminge have more interactive and entertaining games with us. These 3D games use a high definition helmet mounted with LCD or LED screen and 3D stereo headset. The gamers are highly immersed with the gaming scenario and the characters and objects interact with the gamer like live things. Some companies like Sony are now involved in developing games augmented with the VR technology.