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 tointeract 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.

Jonathan Steuer proposed two main components of immersion: depth of information and breadth of information. Depth of information refers to the amount and quality of data in the signals a user receives when interacting in a virtual environment. For the user, this could refer to a display’s resolution, the complexity of the environment’sgraphics, the sophistication of the system’s audio output, et cetera. Steuer defines breadth of information as the “number of sensory dimensions simultaneously presented.” A virtual environment experience has a wide breadth of information if it stimulates all your senses. Most virtual environment experiences prioritize visual andaudio components over other sensory-stimulating factors, but a growing number of scientists and engineers are looking into ways to incorporate a users’ sense of touch. Systems that give a user force feedback and touch interaction are called haptic systems.

For immersion to be effective, a user must be able to explore what appears to be a life-sized virtual environment and be able to change perspectives seamlessly. If the virtual environment consists of a single pedestal in the middle of a room, a user should be able to view the pedestal from any angle and the point of view should shift according to where the user is looking. Dr. Frederick Brooks, a pioneer in VR technology and theory, says that displays must project a frame rate of at least 20 - 30 frames per second in order to create a convincing user experience.

The Virtual Reality Environment

Other sensory output from the VE system should adjust in real time as a user explores the environment. If the environment incorporates 3-D sound, the user must be convinced that the sound’s orientation shifts in a natural way as he maneuvers through the environment. Sensory stimulation must be consistent if a user is to feel immersed within a VE. If the VE shows a perfectly still scene, you wouldn’t expect to feel gale-force winds. Likewise, if the VE puts you in the middle of a hurricane, you wouldn’t expect to feel a gentle breeze or detect thescent of roses.

Lag time between when a user acts and when the virtual environment reflects that action is calledlatency. Latency usually refers to the delay between the time a user turns his head or moves his eyes and the change in the point of view, though the term can also be used for a lag in other sensory outputs. Studies with flight simulators show that humans can detect a latency of more than 50 milliseconds. When a user detects latency, it causes him to become aware of being in an artificial environment and destroys the sense of immersion.

An immersive experience suffers if a user becomes aware of the real world around him. Truly immersive experiences make the user forget his real surroundings, effectively causing the computer to become a non entity. In order to reach the goal of true immersion, developers have to come up with input methods that are more natural for users. As long as a user is aware of the interaction device, he is not truly immersed.

Virtual Reality Interactivity

Immersion within a virtual environment is one thing, but for a user to feel truly involved there must also be an element of interaction. Early applications using the technology common in VE systems today allowed the user to have a relatively passive experience. Users could watch a pre-recorded film while wearing a head-mounted display(HMD). They would sit in a motion chair and watch the film as the system subjected them to various stimuli, such as blowing air on them to simulate wind. While users felt a sense of immersion, interactivity was limited to shifting their point of view by looking around. Their path was pre-determined and unalterable.

Today, you can find virtual roller coasters that use the same sort of technology. DisneyQuest in Orlando, Florida features CyberSpace Mountain, where patrons can design their own roller coaster, then enter a simulator to ride their virtual creation. The system is very immersive, but apart from the initial design phase there isn't any interaction, so it's not an example of a true virtual environment.

Interactivity depends on many factors. Steuer suggests that three of these factors are speed, range and mapping. Steuer defines speed as the rate that a user's actions are incorporated into the computermodel and reflected in a way the user can perceive. Range refers to how many possible outcomes could result from any particular user action. Mapping is the system's ability to produce natural results in response to a user's actions.

Navigation within a virtual environment is one kind of interactivity. If a user can direct his own movement within the environment, it can be called an interactive experience. Most virtual environments include other forms of interaction, since users can easily become bored after just a few minutes of exploration. Computer Scientist Mary Whitton points out that poorly designed interaction can drastically reduce the sense of immersion, while finding ways to engage users can increase it. When a virtual environment is interesting and engaging, users are more willing to suspend disbelief and become immersed.

True interactivity also includes being able to modify the environment. A good virtual environment will respond to the user's actions in a way that makes sense, even if it only makes sense within the realm of the virtual environment. If a virtual environment changes in outlandish and unpredictable ways, it risks disrupting the user's sense of telepresence.

The Virtual Reality Headset

Today, most VE 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.

VE 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.

A data suit to provide user input

Photo courtesy of Dave Pape

Other VE systems project images on the walls, floor and ceiling of a room and are called Cave Automatic Virtual Environments (CAVE). The University of Illinois-Chicago designed the first CAVE display, using a rear projection technique to display images on the walls, floor and ceiling of a small room. Users can move around in a CAVE display, wearing special glasses to complete the illusion of moving through a virtual environment. CAVE displays give users a much wider field of view, which helps in immersion. They also allow a group of people to share the experience at the same time (though the display would track only one user’s point of view, meaning others in the room would be passive observers). CAVE displays are very expensive and require more space than other systems.

Closely related to display technology are tracking systems. Tracking systems analyze the orientation of a user’s point of view so that the computer system sends the right images to the visual display. Most systems require a user to be tethered with cables to a processing unit, limiting the range of motions available to him. Tracker technology developments tend to lag behind other VR technologies because the market for such technology is mainly VR-focused. Without the demands of other disciplines or applications, there isn’t as much interest in developing new ways to track user movements and point of view.

Input devices are also important in VR systems. Currently, input devices range from controllers with two or three buttons to electronic gloves and voice recognition software. There is no standard control system across the discipline. VR scientists and engineers are continuously exploring ways to make user input as natural as possible to increase the sense of telepresence. Some of the more common forms of input devices are:

• Joysticks
• Force balls/tracking balls
• Controller wands
• Datagloves
• Voice recognition
• Motion trackers/bodysuits
• Treadmills

Programmers have developed several different computer languages and Web browsers to achieve this vision. Some of these include:

• Virtual Reality Modeling Language (VRML)- the earliest three-dimensional modeling language for the Web.
• 3DML - a three-dimensional modeling language where a user can visit a spot (or Web site) through most Internet browsers after installing a plug-in.
• X3D - the language that replaced VRML as the standard for creating virtual environments in the Internet.
• Collaborative Design Activity (COLLADA) - a format used to allow file interchanges within three-dimensional programs.

Of course, many VE experts would argue that without an HMD, Internet-based systems are not true virtual environments. They lack critical elements of immersion, particularly tracking and displaying images as life-sized.

In medicine, staff can use virtual environments to train in everything from surgical procedures to diagnosing a patient. Surgeons have used virtual reality technology to not only train and educate, but also to perform surgery remotely by using robotic devices. The first robotic surgery was performed in 1998 at a hospital in Paris. The biggest challenge in using VR technology to perform robotic surgery is latency, since any delay in such a delicate procedure can feel unnatural to the surgeon. Such systems also need to provide finely-tuned sensory feedback to the surgeon.

Another medical use of VR technology is psyc­hological therapy. Dr. Barbara Rothbaum of Emory University and Dr. Larry Hodges of the Georgia Institute of Technology pioneered the use of virtual environments in treating people with phobias and other psychological conditions. They use virtual environments as a form of exposure therapy, where a patient is exposed -- under controlled conditions -- to stimuli that cause him distress. The application has two big advantages over real exposure therapy: it is much more convenient and patients are more willing to try the therapy because they know it isn't the real world. Their research led to the founding of the company Virtually Better, which sells VR therapy systems to doctors in 14 countries.

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 VE 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.

Some psychologists are concerned that immersion in virtual environments could psychologically affect a user. They suggest that VE systems that place a user in violent situations, particularly as the perpetuator of violence, could result in the user becoming desensitized. In effect, there’s a fear that VE entertainment systems could breed a generation of sociopaths. Others aren’t as worried about desensitization, but do warn that convincing VE experiences could lead to a kind of cyber addiction. There have been several news stories of gamers neglecting their real lives for their online, in-game presence. Engaging virtual environments could potentially be more addictive.

Another emerging concern involves criminal acts. In the virtual world, defining acts such as murder or sex crimes has been problematic. At what point can authorities charge a person with a real crime for actions within a virtual environment? Studies indicate that people can have real physical and emotional reactions to stimuli within a virtual environment, and so it’s quite possible that a victim of a virtual attack could feel real emotional trauma. Can the attacker be punished for causing real-life distress? We don’t yet have answers to these questions.

The concept of virtual reality has been around for decades, even though the public really only became aware of it in the early 1990s. In the mid 1950s, a cinematographer named Morton Heilig envisioned a theatre experience that would stimulate all his audiences’ senses, drawing them in to the stories more effectively. He built a single user console in 1960 called the Sensorama that included a stereoscopic display, fans, odor emitters, stereo speakers and a moving chair. He also invented a head mounted television display designed to let a user watch television in 3-D. Users were passive audiences for the films, but many of Heilig’s concepts would find their way into the VR field.

Philco Corporation engineers developed the first HMD in 1961, called the Headsight. The helmet included a video screen and tracking system, which the engineers linked to a closed circuit camera system. They intended the HMD for use in dangerous situations -- a user could observe a real environment remotely, adjusting the camera angle by turning his head. Bell Laboratories used a similar HMD forhelicopter pilots. They linked HMDs to infrared cameras attached to the bottom of helicopters, which allowed pilots to have a clear field of view while flying in the dark.

In 1965, a computer scientist named Ivan Sutherland envisioned what he called the “Ultimate Display.” Using this display, a person could look into a virtual world that would appear as real as the physical world the user lived in. This vision guided almost all the developments within the field of virtual reality. Sutherland’s concept included:

• A virtual world that appears real to any observer, seen through an HMD and augmented through three-dimensional sound and tactile stimuli
• A computer that maintains the world model in real time
• The ability for users to manipulate virtual objects in a realistic, intuitive way

In 1966, Sutherland built an HMD that was tethered to a computer system. The computer provided all the graphics for the display (up to this point, HMDs had only been linked to cameras). He used a suspension system to hold the HMD, as it was far too heavy for a user to support comfortably. The HMD could display images in stereo, giving the illusion of depth, and it could also track the user’s head movements so that the field of view would change appropriately as the user looked around.

Scientists are also exploring the possibility of developing biosensors for VR use. A biosensor can detect and interpret nerve and muscleactivity. With a properly calibrated biosensor, a computer can interpret how a user is moving in physical space and translate that into the corresponding motions in virtual space. Biosensors may be attached directly to the skin of a user, or may be incorporated into gloves or bodysuits. One limitation to biosensor suits is that they must be custom made for each user or the sensors will not line up properly on the user’s body.

Mary Whitton, of UNC-Chapel Hill, believes that the entertainment industry will drive the development of most VR technology going forward. The video game industry in particular has contributed advancements in graphics and sound capabilities that engineers can incorporate into virtual reality systems’ designs. One advance that Whitton finds particularly interesting is the Nintendo Wii’s wand controller. The controller is not only a commercially available device with some tracking capabilities; it’s also affordable and appeals to people who don’t normally play video games. Since tracking and input devices are two areas that traditionally have fallen behind other VR technologies, this controller could be the first of a new wave of technological advances useful to VR systems.

http://www.csc.kth.se/~alx/courses/DT2140/olwal_introduction_to_ar_2010_03_05.pdf

Azuma, R. T. (1997, August). A survey of augmented reality. In Presence: Teleperators and Virtual Environments, 6(4), 355-385. Azuma, R., Baillot, Y., Behringer, R., Feiner, S., Julier, S., & MacIntyre, B. (2001). Recent advances in augmented reality. Computers & Graphics, 1-15. Behzadan, A. H. (2008). ARVISCOPE georeferenced visualization of dynamic construction processes in three-dimensional outdoor augmented reality. Department of Civil and Environmental Engineering, The University of Michigan. Doctor of Philosophy: 282. Billinghurst, M. (2002). Augmented Reality in Education. New Horizons for Learning, December 2002. Retrieved July 20, 2010 from http://www.newhorizons.org/ strategies/technology/billinghurst.htm 136 Journal of Educational Technology Development and Exchange Volume 4, No. 1, October, 2011 Billinghurst, M., Cheok, A., Prince, S., and Kato, H. (2002). Real world teleconferencing. IEEE Computer Graphics and Applications, 22(6), 11-13. Billinghurst, M., and Kato, H. (2002). Collaborative augmented reality. Communications of the ACM, 45(7), 64-70. Billinghurst, M., Kato, H., & Poupyrev, I. (2001). The MagicBook: A Transitional AR Interface. Computers and Graphics, November 2001, 745-753. Billinghurst, M., & Henrysson, A. (2009). Mobile architectural augmented reality. (X. Wang, & M. Schnabel, Eds.) Mixed Reality In Architecture, Design And Construction, 3, 93-104. Biocca, F., & Levy, M. (1995) Communication In The Age of Virtual Reality, Lawrence Erlbaum. Carr, A. (March 31, 2011). BMW to Launch NYC Tech Incubator with $100 million investment fund. Retrieved July 30, 2011 from http://www.fastcompany.com/1743933/ bmw-to-launch-nyc-tech-incubator-with- 100-million-investment-fund Carr, A. (2010, February 11). ZooBurst: Augmented Reality 3-D Pop-up Books for Students and Teachers. Retrieved July 22, 2011 from http://www.fastcompany. com/1644265/zooburst-augmented-reality-3-d-pop-up-books-for-students-andteachers Cho, K., Lee, J., Soh, J., Lee, J., & Yang, H. S. (2007). A realisitc e-learning system based on mixed reality. Proc 13th Intl Conference on Virtual System and Multimedia (pp. 57- 64). VSMM. Classroom Learning with AR (2010). Trends in EdTech wiki. Retrieved July 25, 2010 from http://augreality.pbworks.com/ClassroomLearning-with-AR Cooperstock, J. R. (2001). The classroom of the future: Enhancing education through augmented reality. Proceedings of HCI International, (pp. 688-692). Dede, C. (Speaker). (2008). Immersive interfaces for learning: Opportunities and perils [motion picture]. (Available from The President and Fellows of Harvard College). http://cyber.law.harvard.edu/interactive/ events/luncheon/2008/12/dede Dede, C., et al. (2009). Immersive interfaces for engagement and learning. Science, 323, 66-68. DOI: 10.1126/science.1167311 De Lorenzo, R. (2009). Augmented Reality and On-Demand Learning. The Mobile Learner. Retrieved July 22, 2010 from http://themobilelearner.wordpress.com/2009/10/17/ augmented-reality-and-on-demand-learning/ Dugdale, A. (March 17, 2010). GM to use augmented reality tech for safer driving. Retrieved July 30, 2011 from http://www. fastcompany.com/1586608/gm-to-use-augmented-reality-tech-for-safer-driving Dunleavy, M., Dede, C., & Mitchell, R. (2009, February 1). Affordances and limitations of immersive participatory augmented reality simulations for teaching and learning. Journal of Science Education and Technology, 18(1), 7-22. Fulton, S. III. (May 7, 2007). How Many Users Does Second Life Really Have? Retrieved July 30, 2011 from http://www.betanews. com/article/How-Many-Users-Does-Second-Life-Really-Have/1178573043 Galusha, J. (1997). Barriers to Learning in Distance Education. University of Southern Mississippi. Retrieved September 26, 2011 from http://www.infrastruction.com/barriers.htm Gartner Inc. (2008, May 28). Gartner Identifies Top Ten Disruptive Technologies for 2008 to 2012. Retrieved July 20, 2011 from http://www.gartner.com/it/page. jsp?id=681107

2.)What do you mean by it?

3.)What are the areas where the concepts of Augmented and Virtual Reality can be applied?

4.)What are the benefits of implementing Augmented and virtual reality in our daily lives?

5.)What are the risks associated with the use of Augmented and Virtual reality in day to day uses?