Seminar on
Virtual
Reality
For a next generation
Guided By:-
Prepared By:
B. B. Prajapati
Gajera Jimesh G.
Shantilal Shah Engineering College,
Bhavnagar.
CERTIFICATE
This is to certify that Roll no. of B.E Semester 8 th I.T Class, has satisfactorily
completed his Term work of the subject during the academic year 2010 and submitted on ________
Staff In Charge Head of
Department
Certified that this term work is accepted and assessed on _________
ABSTRACT
Virtual Reality (VR) has been claimed to provide a particularly facilitatory environment for people with Autistic Spectrum Disorders (ASD) in that it offers structure, opportunities for repetition, affective engagement and, control of the learning environment. Virtual reality shares the advantages of computer-based learning, and has the additional advantage of making it more likely that the results will generalise to real-word settings, in that it is a simulation of them. For concept development and imagination training, VR offers its exclusive advantage of making it possible to explicitly show imaginary/magic transformations of how an object can act as if it were a different one, which is useful for training in both abstract concepts and imagination understanding. This paper reviews the relevant issues that need to be addressed when designing and experimentally assessing a tool for this purpose, and concludes with the results of the more relevant research outcomes obtained in this field.
NO. CHAPTER PAGE NO.
1 Introduction 5
2 Concept of Virtual Reality 13
3 History 14
4 Types of VR 19
5 Virtual Reality Environment 26
6 How Virtual Reality Works 29
7 Applications of Virtual Reality 32
8 Future 47
9 Impact of Virtual Reality 54
10 Drawback of Virtual Reality 64
11 Conclusion 68
12 Bibliography 69
1. INTRODUCTION
What is Virtual Reality?
Virtual reality (VR) is a computer-simulated environment, whether that environment is a simulation of the real world or an imaginary world. Most current virtual reality environments are primarily visual experiences, displayed either on a screener through special or stereoscopic displays, but some simulations include additional sensory information, such as sound through speakers or headphones.
Some advanced, hectic systems now include tactile information, generally known as force feedback, in medical and gaming applications. Users can interact with a virtual environment or a virtual artifact (VA) either through the use of standard input devices such as a keyboard and mouse, or through multimodal devices such as a wired glove, the Polhemus boom arm, and omni directional treadmill. The simulated environment can be similar to the real world, for example, simulations for pilot or combat training, or it can differ
significantly from reality, as in VR games. In practice, it is currently very difficult to create a high-fidelity virtual reality experience, due largely to technical limitations on processing power, image resolution and communication bandwidth. However, those limitations are expected to eventually be overcome as processor, imaging and data communication technologies become more powerful and cost-effective over time.
Virtual Reality is often used to describe a wide variety of applications, commonly associated with its immersive, highly visual, 3D environments. The development of CAD software, graphics hardware acceleration, head mounted displays, database gloves and miniaturization have helped popularize the notion. In the book The Metaphysics of Virtual Reality, Michael R. Heim identifies seven different concepts of Virtual Reality: simulation, interaction, artificiality, immersion, telepresence, full-body immersion, and network communication. The definition still has a certain futuristic romanticism attached. People often identify VR with Head Mounted Displays and Data Suits.
Virtual Reality (VR) is stimulating the user’s senses in such a way that a computer generated world is experienced as real. In order to get a true illusion of reality, it is essential for the user to have influence on this virtual environment.
Interaction with a virtual environment
All that has to be done in order to raise the illusion of being in or acting upon a virtual world or virtual environment, is providing a simulation of the interaction between human being and this real environment. This simulation is -at least- partly attained by means of Virtual Reality interfaces connected to a computer. Basically, a VR interface stimulates one of the human senses. This has not necessarily got to
be as complex as it sounds, e.g. a PC-monitor stimulates the visual sense; a headphone stimulates the auditory sense. Consequently, these two kinds of interfaces are widely employed as Virtual Reality interfaces.
A haptic interface (FCS HapticMaster)
With the gustatory and olfactory sense left out of consideration, the hardest part of simulating the interaction between human being and real environment is stimulating the tactile sense and the proprioceptive system (kinesthetic sense). This can be done using a so-called haptic interface. This is a device configured to provide haptic information to a human. Just as a video interface allows the user to see a computer generated scene, a haptic interface permits the user to “feel” it. Haptic displays generate forces and motions, which are sensed through both touch and kinesthesia.
Currently, there are two main kinds of haptic interfaces, namely the off-body interface and the body interface. The main difference is that the mass of the on-body interface is supported by the operator while the off-on-body interface rests on the floor. Nowadays, most commercially available devices are off-body.
The VR-lab
Virtual Reality technology can be usefully applied to a broad range of fields. Within the Virtual Reality laboratory (VR-lab), the emphasis is mainly on two different application areas:
- Virtual Reality as an engineering tool; - Virtual Reality as a medical training tool.
Virtual Reality as an engineering tool
In times of shortened product life cycles and increased product complexity, more responsibility comes with designing a product. Research shows that about 80% of development costs and 70% of life cycle costs of a product are determined during the conceptual phase of this process. This has led to the development of Computer Aided Design (CAD) systems that enable the designer to evaluate the geometry of his virtual design. At this stage of the design process, modifications are still quite cheap, compared with changes to a physical prototype or, even worse, the final product.
Geometric based design has reached a high level of maturity and affordability. Many companies use it to improve the effectiveness and efficiency of the design process. However, for evaluation of a design, the development of physical prototypes still is necessary. This can be a very much time-consuming and expensive process. Therefore, the designer should be able to define and test the desired behaviour of a forthcoming product in such a way that the corresponding geometry is created automatically by means of a CAD system. In order to come to this ideal situation, it should be made possible for the designer to interact with a virtual prototype as he would do with a physical one.
A Virtual Prototyping environment for gearboxes
The answer to more interactive CAD environments is found in the application of Virtual Reality (VR) technology. It allows for interaction with a virtual environment through multiple sensory channels. When VR technology is applied instead of or as a supplement to development of physical prototypes, it is called Virtual Prototyping (VP).
This is the process of using a virtual prototype, in lieu of a physical prototype, for test and evaluation of specific characteristics of a candidate design. A virtual prototype can be defined as a computer-based simulation of a system or subsystem with a degree of functional realism comparable to a physical prototype.
A specific part of Virtual Prototyping is Virtual Assembly (VA). Usually, during the design process, the assembly of a conceptual product is already taken into account. Therefore, a detailed assembly procedure has to be developed without the actual components present. In order to track down the potentially critical operations and geometric conflicts during assembly, physical prototypes are employed. Those physical prototypes have a number of drawbacks, e.g. costly and time-consuming manufacturing, invariability in case of CAD model modifications and immovability caused by mass or extensions. A solution to these problems lies in the application of Virtual Assembly. By utilizing VR technology, various assembly operations can be simulated. This way, not only potentially critical operations and geometric conflicts during assembly can be detected, but also a training tool for shop floor workers is provided.
Virtual Reality as a medical training tool
Patients nowadays expect the best treatment possible. The common way for a surgeon student to acquire experience is by “on the fly” learning from an experienced surgeon. This way of teaching has besides many good points some drawbacks. Patients are needed for these educational purposes. These operations take more time thus expensive extra operating-room time is used. The quality depends highly on the educational skills of the experienced doctor.
The aim of using Virtual Reality as a medical training tool is to offer additional means to teach surgeon student. The goal is to halve the “on the fly” learning in the operating room with real patients and to improve the quality of the medical treatment.
Within a virtual operating room the student will be able to practice the technical skills, the procedures and the theoretical background of operations and diseases.
Currently the main research attention is paid to the development of this virtual operating room. With two haptic devices, a 3D vision, a 3D model system and an assessment program an environment will be created in which surgeon students can improve and test their operating skills.
2. CONCEPT OF VIRTUAL REALITY
The term "artificial reality", coined by Myron Krueger, has been in use since the 1970s, but the origin of the term "virtual reality" can be traced back to the French playwright, poet, actor and director Antonin Artaud. In his seminal book The Theatre and Its Double (1938), Artaud described theatre as "la réalite
virtuelle", a virtual reality "in which characters, objects, and images take on the
phantasmagoric force of alchemy's visionary internal dramas". It has been used in The Judas Mandala, a 1982 science-fiction novel by Damien Broderick, where the context of use is somewhat different from that defined above.
The earliest use cited by the Oxford English Dictionary is in a 1987 article titled "Virtual reality", but the article is not about VR technology. The concept of virtual reality was popularized in mass media by movies such as
Brainstorm (filmed mostly in 1981) and The Lawnmower Man (plus others
mentioned below). The VR research boom of the 1990s was accompanied by the non-fiction book Virtual Reality (1991) by Howard Rheingold. The book served to
demystify the subject, making it more accessible to less technical researchers and enthusiasts, with an impact similar to that which his book The Virtual
Community had on virtual community research lines closely related to
VR. Multimedia: from Wagner to Virtual Reality, edited by Randall Packer and Ken Jordan and first published in 2001, explores the term and its history from an avant-garde perspective. Philosophical implications of the concept of VR are systematically discussed in the book Get Real: A Philosophical Adventure in
Virtual Reality (1998) by Philip Zhai, wherein the idea of VR is pushed to its
logical extreme and ultimate possibility. According to Zhai, virtual reality could be made to have an ontological status equal to that of actual reality.
3. HISTORY
In the 1560s 360-degree art through panoramic murals were believed to have started the idea of virtual reality. An example of this would be Baldassare Peruzzi's piece titled, "Sala delle Prospettive".
In 1920s vehicle simulators were introduced. Morton Heilig wrote in the 1950s of an "Experience Theatre" that could encompass all the senses in an effective manner, thus drawing the viewer into the onscreen activity. He built a prototype of his vision dubbed the Sensorama in 1962, along with five short films to be displayed in it while engaging multiple senses (sight, sound, smell, and touch). Around this time Douglas Englebart uses computer screens as both input and output devices.
In 1966 Tom Furness introduces a visual flight stimulator for the Air Force. In 1968, Ivan Sutherland, with the help of his student Bob Sproull, created what is widely considered to be the first virtual reality and augmented reality (AR) head mounted display (HMD) system. It was primitive both in terms of user interface
and realism, and the HMD to be worn by the user was so heavy it had to be suspended from the ceiling, and the graphics comprising the virtual environment were simple wireframe model rooms. The formidable appearance of the device inspired its name, The Sword of Damocles. Also notable among the earlier hypermedia and virtual reality systems was the Aspen Movie Map, which was created at MIT in 1977.
The program was a crude virtual simulation of Aspen, Colorado in which users could wander the streets in one of three modes: summer, winter, and polygons. The first two were based on photographs — the researchers actually photographed every possible movement through the city's street grid in both seasons — and the third was a basic 3-D model of the city. In the late 1980s the term "virtual reality" was popularized by Jaron Lanier, one of the modern pioneers of the field. Lanier had founded the company VPL Research (from "Visual Programming Languages") in 1985, which developed and built some of the seminal "goggles and gloves" systems of that decade.
The creation of virtual reality has been slow going, arduous and, up until the mid-‘90s, largely theoretical in nature. In 1965 Ivan Sutherland, an ARPA scientist, published his grand oeuvre “The Ultimate Display.” In his essay Sutherland predicted all sorts of advances in computer technology: computer mice, drag and drop interfaces and voice recognition software. But most importantly, he wrote about the ultimate display—“a room within which the computer can control the existence of matter.” Sutherland’s essay might have been full of fanciful speculations about the future of digital technology, but his wild (and shockingly accurate) predictions helped plant the seed of VR in the minds of scientists and non-scientists to follow.
In 1968 with the help of one of his assistants, Sutherland created one of the first head mounted augmented reality display systems—what would come to be known through movies and TV as a VR helmet—known to some as The Sword of
Damocles because it was so big and heavy that it had to be suspended precariously
over the user’s head with a series of cables. The display only showed the users crude outlines of a virtual environment.
Despite the technology’s scientific beginnings, however, VR made its first major strides in fiction. The movie TRON had people imagining the possibilities of interactive gaming to the Nth degree. William Gibson rocked the minds of a
generation when he wrote of a cyber-punk society where a brain-computer interface was possible in Neuromancer. Ray Bradbury took the concept of a VR room to its most horrific extreme in The Veldt.
And while VR charged ahead in the realm of fiction, in the field of science it scrambled to keep up.
The first major technical leap forward came in the mid-‘70s in the form of Myron Krueger’s VIDEOPLACE. Using cameras, computers and projectors, people in a VR room were able to see and interact with silhouettes of people in other similar rooms. Compared to the advances that writers and directors of the time were coming up with, VIDEOPLACE was crude, but Krueger’s experiments showed that science was at least trying to move forward with VR.
So, Virtual reality had bounded forward in one of the five senses—sight— but that left the other four to conquer. Soon scientists were trying to combine systems like VIDEOPLACE with data gloves and tactile interfaces. The leader in this field was Jaron Lanier.
In fact, he popularized the term virtual reality. In 1985 Lanier founded a company called VPL Research and began experimenting with all sorts of goggle and glove set ups.
Initially, the video game market, captivated by the possibilities of VR, tried to cash in on the early advancements. Who could forget that seminal scene in the classic movie Wizard where the badass townie unlocks a Nintendo power glove from a carrying case and proceeds to school all those who dare come up against him? Or the phase in the mid-‘90s where you could stand on a giant platform, put on a ridiculously large helmet and box a 16-bit opponent with Nintendo Wii-like controllers?
But all of these attempts to game with VR would quickly fade away—most in less than a year. The tech was too expensive, the equipment was too bulky and the graphics and game play offered weren’t up to par. So, gaming companies quickly cut their losses and left VR to the scientists and the artists, and they had a field day.
Since the late ‘80s virtual reality has been popping up everywhere in movies and TV. The Lawnmower man, VR5, Virtuosity, eXistenZ, and most famously The Matrix imagined worlds where the goggles and gloves were obsolete; it was all about beaming the information directly into the user’s brain.
Science too kept pursuing the elusive brass ring of VR, but direct to brain transmission was and is still a little invasive for the scientific community (However, this didn’t stop Sony from patenting the idea that information could someday be beamed into a human’s brain earlier this year). Instead, they concentrated on better, less intrusive helmets, more efficient interfaces and more realistic 3D modeling.
Virtual Reality in… Reality
This brings us to today. Current VR technology, while more impressive than anything we’ve had before, still falls short of what we imagined it could be. Most systems can only manage to immerse two senses at a time: The VR systems that therapists use to help treat client phobias or PTSD use helmets or small rooms to simulate sights and sounds; The Nintendo Wii allows people to physically interact with a virtual opponent.
But science is getting tired of this plateau it’s been stuck on. In the last few years, researchers in the field of VR have been stretching themselves to hit more of the five senses.
One of the biggest innovations in VR came earlier this year. Sight and sound have always been the go-to senses for virtual reality researchers, but few have ventured into the realm of taste and smell. In March 2009 a team of scientists from the Universities of York and Warwick in the U.K. revealed what they saw as a giant leap forward in VR tech, the Virtual Cocoon. The cocoon not only simulates the looks and sounds of a 3D environment on the inside of a portable helmet, it also has a library of smells and tastes it can feed to the user to correspond to the world they are experiencing.
Which just leaves one last aspect of creating a truly immersive virtual reality system–the ever elusive locomotion? You can create life-like graphics and simulate realistic sounds, you can feed them tastes and smells, but as soon as your test subject takes their first step to explore your virtual world, you’re in trouble, and a virtual world the size of your living room just doesn’t do it for most people.
To get around this problem, a company called Cyberwalk has started work on an omni-directional treadmill they call the CyberCarpet. This would allow people to walk in any direction for as long as they want without hitting a wall or walking into traffic. When combined with something like the Virtual Cocoon, we’re the closest we’ve ever been to escaping this troublesome world in favour of an ideal one of our own making.
We may have waited a long time, and the technology might be in its infancy, but we may have our VR rooms and Holodecks sooner that we think.
4. MAIN TYPES OF VR
(Classified by display technology)
Although it is difficult to categorise all VR systems, most configurations fall into three main categories and each category can be ranked by the sense of immersion, or degree of presence it provides. Immersion or presence can be regarded as how powerfully the attention of the user is focused on the task in hand. Immersion presence is generally believed to be the product of several parameters
including level of interactivity, image complexity, stereoscopic view, field of regard and the update rate of the display. For example, providing a stereoscopic rather than monoscopic view of the virtual environment will increase the sense of immersion experienced by the user. It must be stressed that no one parameter is effective in isolation and the level of immersion achieved is due to the complex interaction of the many factors involved.
As will be shown in this report, the type of VR system being used an important consideration when one investigates the genesis of sickness symptoms and the type of symptoms that may develop.
Non-Immersive (Desktop) Systems
Non-immersive systems, as the name suggests, are the least immersive implementation of VR techniques. Using the desktop system, the virtual environment is viewed through a portal or window by utilising a standard high resolution monitor. Interaction with the virtual environment can occur by conventional means such as keyboards, mice and trackballs or may be enhanced by using 3D interaction devices such as a SpaceBallä; or DataGloveä; .
The non-immersive system has advantages in that they do not require the highest level of graphics performance, no special hardware and can be implemented on high specification PC clones. This means that these systems can be regarded as the lowest cost VR solution which can be used for many applications. However, this low cost means that these systems will always be outperformed by more sophisticated implementations, provide almost no sense of immersion and are limited to a certain extent by current 2D interaction devices.
Additionally, these systems are of little use where the perception of scale is an important factor. However, one would expect to see an increase in the popularity of such systems for VR use in the near future. This is due to the fact that Virtual Reality Modelling Reality Language (VRML) is expected to be adopted as a de-facto standard for the transfer of 3D model data and virtual worlds via the internet. The advantage of VRML for the PC desktop user is that this software runs relatively well on a PC, which is not always the case for many proprietary VR authoring tools. Furthermore, many commercial VR software suppliers are now incorporating VRML capability into their software and exploring the commercial possibilities of desktop VR in general.
Semi-Immersive Projection Systems
Semi-immersive systems are a relatively new implementation of VR technology and borrow considerably from technologies developed in the flight simulation field.
A semi-immersive system will comprise of a relatively high performance graphics computing system which can be coupled with either:
• A large screen monitor
• A large screen projector system
• Multiple television projection systems
In many ways, these projection systems are similar to the IMAX theatres discussed in section 1.1. Using a wide field of view, these systems increase the feeling of immersion or presence experienced by the user. However, the quality of the projected image is an important consideration. It is important to calibrate the geometry of the projected image to the shape of the screen to prevent distortions and the resolution will determine the quality of textures, colours, the ability of define shapes and the ability of the user to read text on-screen. The resolutions of projection systems range from 1000 - 3000 lines but to achieve the highest levels it may be necessary to use multiple projection systems which are more expensive.
Semi-immersive systems therefore provide a greater sense of presence than non-immersive systems and also a greater appreciation of scale. In addition, images can be provided that are of a far greater resolution than HMDs and this implementation provides the ability to share the virtual experience.
This may have a considerable benefit in educational applications as it allows simultaneous experience of the VE which is not available with head-mounted immersive systems. Additionally, stereographic imaging can be achieved, using some type of shuttered glasses in synchronisation with the graphics system.
Shutter Glasses
Liquid Crystal Shutter (LCS) glasses are an important technology when considering semi-immersive systems and consist of a lightweight headset with a
liquid crystal lens placed over each eye. Stereopsis works on the principle that in order to perceive depth in a scene, the observer must see slightly different images of the scene under regard in each eye. In the real world this occurs because the two eyes are placed slightly apart in the head, and so each eye views the scene from a slightly different position.
The graphics computer used displays slightly different left and right views (known as a stereo pair) of the virtual environment sequentially on the display system. To achieve the stereoscopic effect, the glasses either pass or block an image that is produced on the VDU or projected display. When the left image is displayed, the left eye lens is switched on, allowing the viewer’s left eye to see the screen. The right eye lens, however, remains off, thus blocking the right eyes view. When the right image is displayed, the opposite occurs. This switching between images occurs so rapidly that it is undetectable by the user, who fuses the two images in the brain to see one constant 3D image.
Picture courtesy of Loughborough University Advanced VR Research Centre Figure 1. A semi-immersive wide-screen projection system in use with shutter glasses.
Examples of this product commercially available include CrystalEyes Shutter Glasses and the 3D Max Shutter Glasses System.
Again however, the increased performance of this VR implementation comes at a cost. Setting up a projection screen system is far more difficult than a desktop system and is considerably more expensive. Additionally, there are problems with current interaction devices for these systems. Firstly, one must consider carefully the applications that such a system may be used for. For a flight simulation system it is possible to simply used an inceptor (joystick) which can be interpreted by the aircraft model as the flight control input. This is acceptable as the simulator is not used for any other applications but becomes problematical when one considers that a semi-immersive installation may have multifarious uses that may require different interaction strategies. Secondly, one must consider multi-user issues, as this is one of the main advantages of these systems. The handover of control between users is one of the issues that must be considered as this technology develops.
Fully Immersive Head-Mounted Display Systems
The most direct experience of virtual environments is provided by fully immersive VR systems. These systems are probably the most widely known VR implementation where the user either wears an HMD or uses some form of head-coupled display such as a Binocular Omni-Orientation Monitor or BOOM (Bolas, 1994).
Head Mounted Displays (HMDs)
An HMD uses small monitors placed in front of each eye which can provide stereo, bi-ocular or monocular images. Stereo images are provided in a similar way to shutter glasses, in that a slightly different image is presented to each eye. The major difference is that the two screens are placed very close (50-70mm) to the eye, although the image, which the wearer focuses on, will be much further away because of the HMD optical system. Bi-ocular images can be provided by displaying identical images on each screen and monocular images by using only one display screen.
The most commonly used displays are small Liquid Crystal Display (LCD) panels but more expensive HMDs use Cathode Ray Tubes (CRT) which increase the resolution of the image. The HMD design may partially or fully exclude the users view of the real world and enhances the field of view of the computer
generated world. The advantage of this method is that the user is provided with a 360°; field of regard meaning that the user will receive a visual image if they turn their head to look in ANY direction.
All fully immersive systems will give a sense of presence that cannot be equalled by the other approaches discussed earlier, but the sense of immersion depends of several parameters including the field of view of the HMD, the resolution, the update rate, and contrast and illumination of the display.
Image courtesy of VISERG, Loughborough University
Figure 2. The major components of an HMD. This illustration shows the two screens capable of producing stereo images and speakers located to provide stereo sound.
Fully immersive VR systems tend to be the most demanding in terms of the computing power and level of technology (and consequently cost!) required to achieve a satisfactory level of realism and development is constantly underway to improve the technologies. Major areas of research and development include field of view vs resolution trade-offs, reducing the size and weight of HMDs and reducing system lag times.
Kalawsky (1996) provides a good comparison between the various VR implementations (see Table 2.1). It is also important that these implementations are not regarded as distinct boundaries for implementations. For example, it is possible to turn a desktop system into a semi-immersive system by simply adding shutter glasses and the appropriate software, or a fully immersive system by connecting an HMD.
Table 2.1
Qualitative performance of different VR systems (adapted from Kalawsky, 1996)
Qualitative Performance
Main Features Non- Immersive VR (Desktop) Semi-Immersive VR (Projection) Full Immersive VR (Head-coupled)
Resolution High High Low - Medium
Scale
(perception)
Low Medium - High High
Sense of
situational awareness (navigation skills)
Low Medium High
Field of regard Low Medium High
Sense of immersion
None - low Medium - High Medium - High
5. 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 the scent of roses.
Lag time between when a user acts and when the virtual environment reflects that action is called latency. 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.
USING an inventive new method in which mice run through a virtual reality environment based on the video game Quake, researchers from Princeton University have made the first direct measurements of the cellular activity associated with spatial navigation. The method will allow for investigations of the neural circuitry underlying navigation, and should lead to a better understanding of how spatial information is encoded at the cellular level.
In mice, spatial navigation involves at least four different cell types located in the hippocampus and surrounding regions. Place cells increase their activity when the animal is in a specific location within its environment, called the place field.
Grid cells, by contrast, fire periodically as the animal traverses a space; each has a unique periodicity, and apparently measures out the space using its own scale. Head direction cells, as their name implies, fire when the animal is facing a particular direction and border cells, which were identified only last year, encode the animal's distance from the borders within its environment.
Place cells were discovered almost 40 years ago and are the most extensively studied of these cell types. Their activity is typically recorded using small arrays of microelectrodes implanted within the hippocampus of a freely moving rodent. The arrays can remain in place for days or weeks, during which time they can be used to monitor changes in place cell firing rates, and how the acitivty of cells is related to the animal's movements within its environment. They record from afar, because the animal's movements prevent them from coming into, and maintaining, close contact with the cells.
In the ingenious set-up devised by members of David Tank's laboratory, the mice were restrained, and ran on a spherical treadmill supported by a jet of air. Information about the rotation of the treadmill was used to control the animals' movements along a computer-generated track which was projected onto a surrounding screen.
In this virtual environment, the place cells behaved as expected. All the cells from which recordings were made generated short, regular bursts of nervous impulses, separated by intervals of about one tenth of a second,.
This produced a low level of background activity called the theta oscillation, which has a frequency of 6-10 cycles per second, and which is characteristic of the hippocampus. The actvity of individual place cells was modulated by location. As the animal entered a given place field, the corresponding place cell increased its firing rate almost five-fold, to generate a rhythmic discharge with a higher frequency than the background.
Because the animals were stationary, the electrodes could be used to record directly from the place cells, enabling the researchers to measure their dynamical electrical properties. This revealed how their firing rate increases: as the mouse approached a place field, the corresponding cell would ramp up its resting membrane voltage. This would cause the cell to increase the frequency of its impulses while the mouse ran through the field. When the animal emerged from the other side of the field, the membrane voltage would go back down to its normal level, and the frequency of impulses would decrease again. The background activity of single cells was also found to increase while the animal was in the appropriate location.
These findings are consistent with the predictions of a model which states that place cell activity is modulated by interactions between two separate oscillating inputs. The data do not exclude other possibilities, however, and the availablity of this virtual reality system will enable researchers to study the activity of place cells in greater detail, because it offers researchers the ability to design highly customized environments, and can be used in combination with other techniques such as two-photon laser scanning microscopy.
6. HOW VIRTUAL REALITY WORKS
What do you think of when you hear the words virtual reality (VR)? Do you imagine someone wearing a clunky helmet attached to a computer with a thick cable? Do visions of crudely rendered pterodactyls haunt you? Do you think of Neo and Morpheus traipsing about the Matrix? Or do you wince at the term, wishing it would just go away?
If the last applies to you, you're likely a computer scientist or engineer, many of whom now avoid the words virtual reality even while they work on technologies most of us associate with VR. Today, you're more likely to hear someone use the words virtual environment (VE) to refer to what the public knows as virtual reality.
Fig: A virtual reality CAVE display projecting images onto the floor, walls and ceiling to provide full immersion.
Naming discrepancies aside, the concept remains the same - using computer technology to create a simulated, three-dimensional world that a user can manipulate and explore while feeling as if he were in that world.
Scientists, theorists and engineers have designed dozens of devices and applications to achieve this goal. Opinions differ on what exactly constitutes a true VR experience, but in general it should include:
• Three-dimensional images that appear to be life-sized from the
perspective of the user
• The ability to track a user's motions, particularly his head
and eye movements, and correspondingly adjust the images on the user's display to reflect the change in perspective.
Have you ever wondered how does virtual reality work? Well, you are not alone. Virtual reality is overtaking the real world and you cannot help but come into contact with virtual environments.
What is a virtual environment? A virtual reality space is said to exist when a 3D computer generated world has been created. This world must allow users to interact with the environment and each other and leave the user with the feeling that he is actually in the virtual environment.
Universities and schools use virtual reality to
interact with students. Businesses use virtual reality to communicate and to advertise. Online gaming uses virtual reality to create realistic gaming scenarios. The uses of virtual reality are endless.
For an experience to qualify as a virtual reality experience it must both immerse you in the virtual world and allow you to interact with the environment and others in the environment. The combination of immersion and the ability to interact is known as telepresence. If either of these qualities is missing you will not have a true virtual experience.
How Does Virtual Reality Work? Dive Right In!
To understand how virtual reality works you must understand the concept of immersion. Immersion allows users to feel as if they exist within the virtual world.
In order for a user to feel he is in a virtual world the world must appear to be a regular sized world where perspectives and movement can be achieved effortlessly.
Immersion includes such concepts as sight and sound. A user must be able to see in the virtual world as he does in the real world. If looking at a tree the user must be able to walk around the tree and view it from many perspectives.
Sound is a major component of how virtual reality works. In the real world sounds are heard in different volumes, pitches, and tones depending on where you are and how you are moving. A virtual world must recreate this experience.
If a user becomes aware of the real world environment the virtual world has failed. The goal of immersion is for the virtual world to mimic the real world to the point that a user will be “lost” in the virtual environment and forget he is using a computer or that the real world exists.
How Does Virtual Reality Work? With Inter-Action
The second component of a virtual world, and a driving force behind how a virtual world works, is interaction. Users in the virtual world must be able to interact with other users and the virtual environment.
Interaction with others in virtual worlds can be accomplished via text or speech. A keyboard will allow users to communicate with other users in text format. Microphones and headsets let users communicate using speech.
Interaction with the environment means that the user has the ability to move objects in his environment. The virtual user can move in the virtual environment and do many things he would in the real world.
As with immersion, interaction must be seamless. There should be no lag time between your real life movements, (or speech), and the corresponding actions in the virtual world. Lag time will cause the virtual experience to be limited.
Understanding how virtual reality works will make your life easier. Many virtual reality programs are currently being created to make users’ daily lives more pleasant. Once you understand how virtual reality works you can dive into the virtual world.
7. APPLICATIONS OF VIRTUAL REALITY
VIRTUAL REALITY IS WELL KNOWN for its use with flight simulators and games. However, these are only two of the many ways virtual reality is being used today. This article will summarize how virtual reality is used in medicine, architecture, weather simulation, chemistry and the visualization of voxel data. In addition, links to web pages where other uses of virtual reality are detailed are included at the end of this article.
Medicine
Mark Billinghurst, at the Hit Lab in Washington, has developed a prototype surgical assistant for simulation of paranasal surgery. During a simulated operation the system provides vocal and visual feedback to the user, and warns the surgeon when a dangerous action is about to take place. In addition to training, the expert assistant can be used during the actual operation to provide feedback and guidance. This is very useful when the surgeon's awareness of the situation is limited due to complex anatamoy.
Finally, Billinghurst and his associates are working at developing a toolkit for physicians which will help them create their own expert assistants for other types of surgery.
Architecture
The department of visualization and virtual reality at the IGD University in Germany has developed a program that uses radiosity and raytracing to simulate light. This virtual reality program has applications in the area of architecture and light engineering.
With light simulation architects can examine how outdoor light will fall inside and outside their building before it is built. If the lighting needs to be redesigned, the architect can redesign the building on the computer and examine the new outdoor light effects.
In addition to outdoor light, lighting engineers use virtual reality to examine the effects of point lights, spotlights and other indoor light sources. An interior designer could examine how light will affect different room arrangements.
Weather Simulation
Fraunhaufer-IGD has developed a visualization system for weather forecasting called "TriVis". TriVis accepts data from meteorological services such as satellite data, statistically corrected forecast data, precipitation data and fronts information. It then analyzes this data and uses fractal functions to create projections of storm systems. Using TriVis to visualize artificial clouds, meteorologists can predict weather with increased accuracy.
The data gathered and analyzed by the TriVis system is used by television weather reporters to show their audiences storm systems. TriVis has been used in television weather forecasts since 1993.
Chemistry
Real Mol is a program that uses virtual reality to show molecular models in an interactive, immersive environment. The scientist who uses the program wears a cyberglove and a head mounted display to interact with the molecular system. Using RealMol scientists can move molecules or protein chains to create new molecules. This is useful in fields such as drug design.
RealMol displays molecules in three ways: ball and stick model, stick model and CPK model. The molecules are rendered through a molecular dynamics simulation program.
Voxel Data
ISVAS is an interactive software program that is utilized to analyze 3D and voxel data. It was developed by Fraunhofer-LBF. Using this program, scientists can analyze vector or scalar values.
A similar program was used by students at UCSD to analyze the voxel data obtained when observing the solar winds. The image at left is a small
version of the visualization of the voxel data that depicts the solar wind patterns.
Other Applications of Virtual Reality
Flight Simulator
Museums and Cultural Heritage
Financial Data
Training: Hubble Telescope
On the Net: VR Resources
Eighteen professors from five departments decide to work together and submit a request for a virtual reality system. Suppose further that the administration actually believes that this is a wonderful idea and approves the proposal, provided that the virtual reality system is put to use in the classroom. The faculty eagerly agree to this condition, and to their amazement they acquire the funds to purchase an SGI Onyx 2 Reality Engine and 10 SGI Indigos.
The above scenario is not some introduction to a John Grisham suspense novel, but a real story at Clemson University. Recently Steve (D.E.) Stevenson from the Department of Computer Science at Clemson University came to the Geometry Center and talked about applications of Geometry with computers. Steve mentioned briefly how various departments had been using the virtual reality system they acquired, and showed specific examples of what they had done with them.
The departments using the system range from those which traditionally might use virtual reality, such as the Computer Science department, the Mechanical Engineering department and the Architecture department, to fields not generally associated with the technology such as the Biomedical Engineering department and the Performing Arts department. All these disciplines' projects use the technology in ways that create images and objects that otherwise would take a long time to construct, or not be feasible to construct at all.
In particular, software is currently under development for Mechanical Engineering students that extends CAD/CAE software to virtual reality. Instead of clicking keystrokes to try to alter perspective views, a user is able to wear a helmet and by moving their head around are able to view an object as if it were before them. Moreover one is able to look through different layers of an object to view how the device is operating internally. Although these are all things that CAD/CAE software allows, the virtual reality system gives a user a more natural way to view an object, which accordingly allows one to easier ask the question, "what if?"
Some of the other projects involving engineering are simulation-based design, multipurpose design optimization and visualization in High Performance Computing-Computer Formulated Design structures. Lastly one professor dreams of creating a simulation of the famous Tacoma Narrows bridge collapsing so that Civil and Mechanical Engineers can fully appreciate the consequences of their errors.
In the Biomedical Engineering department some of the projects mentioned are use of virtual reality for viewing of X-RAY's and MRI's, using stereolithography to make prototypes of joints, and even having students perform test surgery.
In the Computer Science department some of the projects range from creating a toolkit for non-computer science designers, rendering and 3-D lighting, viewing non-euclidean geometries, and modeling for resource management.
Projects in the Architecture department include creating a virtual reality model of campus, and a laboratory on building design.
People in the Performing Arts department use virtual reality for Stage Lighting and Stage Design Courses.
Of the above projects, two of the more interesting applications common to both Mechanical Engineering and Biomedical Engineering, involve stereolithography or 3D printing. One is able to design or input given data about an object and actually create a prototype made out of polymers of the object viewed in the virtual reality. One interesting example is that of an image of a Pelvis taken from an MRI, piped into the virtual reality software so that one is able to view it, and then a model of the bone is manufactured using the polymer machine. The following figure is a virtual reality image of this pelvis.
Similarly, a model of a "ship in a bottle" was created using CAD/CAE software viewed through the virtual reality software, and then made.
The virtual reality machines nicely compliment the polymer machine. One is able to thoroughly view an object before making a prototype, thus saving on the production costs of making a prototype.
The Computer Science department has also created some interesting programs. Two software programs are titled Steve's Room and Oliver's Room. Steve's Room is a program which allows the user via the helmet to look around a room, turn on lights, and place objects by voice or mouse commands. Oliver's Room also is a high resolution room. In this room, one can see in high resolution, an Impressionist painting on the wall, a tiled floor, and a window with a view of mountains. The following picture is a view of Oliver's Room.
As with Steve's Room, the user is able via voice commands to move about the room. The next picture is an image of what one might see through the helmet after a request to move has been made.
The visual results from these projects are amazing, both in a practical sense and in a pure aesthetic sense. The images created are useful in understanding the structure of an object, as well as being suitable for framing. However, what is equally impressive is that various departments were able to get together and pool their resources so that this system could be acquired. By doing this, they have provided themselves, and more importantly, their students, an opportunity to use computer systems today that will no doubt be commonplace in the future.
Mass
Media:-Mass media has been a great advocate and perhaps a great hindrance to its development over the years. During the research “boom” of the late 1980s into the 1990s the news media's prognostication on the potential of VR — and potential overexposure in publishing the predictions of anyone who had one (whether or not that person had a true perspective on the technology and its limits) — built up the expectations of the technology so high as to be impossible to achieve under the technology then or any technology to date. Entertainment media reinforced these concepts with futuristic imagery many generations beyond contemporary capabilities.
Fiction books
Many science fiction books and movies have imagined characters being "trapped in virtual reality". One of the first modern works to use this idea was
Daniel F. Galouye's novel Simulacron-3, which was made into a German teleplay titled Welt am Draht ("World on a Wire") in 1973 and into a movie titled The Thirteenth Floor in 1999. Other science fiction books have promoted the idea of virtual reality as a partial, but not total, substitution for the misery of reality (in the sense that a pauper in the real world can be a prince in VR), or have touted it as a method for creating breathtaking virtual worlds in which one may escape from Earth's now toxic atmosphere. They are not aware of this, because their minds exist within a shared, idealized virtual world known as Dream Earth, where they grow up, live, and die, never knowing the world they live in is but a dream.
Stanislaw Lem wrote a short story in early 1960 called "dziwne skrzynie profesora Corcorana” in which he presented a scientist who devised a completely artificial virtual reality. Among the beings trapped inside his created virtual world, there is also a scientist, who also devised such machines creating another level of virtual world.
The Piers Anthony novel Killobyte follows the story of a paralyzed cop trapped in a virtual reality game by a hacker, whom he must stop to save a fellow trapped player with diabetes slowly succumbing to insulin shock. This novel toys with the idea of both the potential positive therapeutic uses, such as allowing the paralysed to experience the illusion of movement while stimulating unused muscles, as well as virtual realities' dangers.
An early short science fiction story — "The Veldt" — about an all too real "virtual reality" was included in the 1951 book The Illustrated Man, by Ray Bradbury and may be the first fictional work to fully describe the concept.
Phillip K Dick's 1964 The Three Stigmata of Palmer Eldritch includes Perky Pat 'layouts', small physical representations of the world exact in every detail complete with dolls. With the help of an interface in the form of a drug, people immerse, or 'translate', themselves totally into these worlds to escape the tedium of their lives as colonists on other planets of the solar system.
Vernor Vinge's True Names, published in 1981, imagines a virtual world which is probably the first to represent a metaverse as it was later to be characterised by such authors as William Gibson and Neal Stephenson. In True Names characters interact with each other in a complete world where they can have homes and work and are represented using avatars. This kind of virtual world was later to be realised as Second Life, which was launched in 2003.
The Otherland series of 4 novels by Tad Williams, published between 1996 and 2001 and set in the 2070s, show a world where the Internet has become accessible via virtual reality and has become so popular and commonplace that, with the help of surgical implants, people can connect directly into this future VR environment. The series follows the tale of a group of people who, while investigating a mysterious illness attacking children while in VR, find themselves trapped in a virtual reality system of fantastic detail and sophistication unlike any the world has ever imagined.
Other popular fictional works that use the concept of virtual reality include William Gibson's Neuromancer which defined the concept of cyberspace, Neal Stephenson's Snow Crash, in which he made extensive reference to the term avatar to describe one's representation in a virtual world, and Rudy Rucker's The Hacker and the Ants, in which programmer Jerzy Rugby uses VR for robot design and testing.
Another use of VR is in the teenage book "The Reality Bug" by D.J MacHale, where the inhabitants of a territory can have their own perfect virtual world, causing everyone to neglect the real world. To cause everyone to spend less time there, a virus is introduced that should make it slightly less than perfect. However, it is so powerful it introduces their worst nightmares, and eventually physically breaks out of the computer until it is shut down.
Alexander Besher's Rim: A Novel of Virtual Reality is similar to Otherland, however it also shows the urban decay that obsession with VR has caused, and the devastating effects to the economy it causes after a major crash leaves millions of users in a coma and some dead.
Television
Perhaps the earliest example of virtual reality on television is a Doctor Who
serial "The Deadly Assassin". This story, first broadcast in 1976, introduced a dream-like computer-generated reality known as the Matrix (no relation to the film — see below). The first major American television series to showcase virtual reality was Star Trek: The Next Generation. Several episodes featured a holodeck, a virtual reality facility that enabled its users to recreate and experience anything they wanted. One difference from current virtual reality technology, however, was that replicators, force fields, holograms, and transporters were used to actually recreate and place objects in the holodeck, rather than illusions of physical objects, as is done today.
In Japan and Hong Kong, the first anime series to use the idea of virtual reality was Video Warrior Laserion (1984).
An anime series known as Serial Experiments Lain included a virtual reality world known as "The Wired" that eventually co-existed with the real world.
Cult British BBC2 sci-fi series Red Dwarf featured a virtual reality game titled Better Than Life, featuring a plot where the main characters had spent many years connected to the game. This was elaborated on in the book, based on the series' episodes, of the same name. Virtual reality has also been featured in other Red Dwarf episodes including Back to Reality, where venom from the despair squid caused the characters to believe all their experiences on Red Dwarf had been part of a VR simulation. Other episodes that feature Virtual reality include Gunmen of the Apocalypse, Stoke Me a Clipper, Blue, Beyond a Joke, and Back in the Red.
Children's television show Are You Afraid Of The Dark? uses the concept of virtual reality as the premise of the episode "The Tale Of The Renegade Virus" (1993).
Channel 4's Gamesmaster (1992 – 1998) also used a VR headset in its "tips and cheats" segment.
BBC 2's Cyberzone (1993) was the first true "virtual reality" game show. It was presented by Craig Charles.
FOX's VR.5 (1995) starring Lori Singer and David McCallum, used what appeared to be mistakes in technology as part of the show's on-going mystery.
In 2002, Series 4 of hit New Zealand teen sci-fi TV Series, The Tribe
featured the arrival of a new tribe to the city, The Technos. They tried to gain power by introducing Virtual Reality to the city. The tribes would battle each other in the Virtual World in a "game" designed by the leader of The Techno's, Ram. However, the effects of VR on the people turned nasty when they started to fight in the real world as well, after too much use made them unable to tell the difference between what was real and what was virtual.
In 2005, Brazilian's Globo TV features a show where VR helmets are used by the attending audience in a space simulation called Conquista de Titã, broadcasted for more than 20 million viewers weekly.
In the anime version of Yu-Gi-Oh!, one three-part episode sees the heroes entering a virtual world based on the game Duel Monsters, where the players must use their cards to work their way through a series of story-based challenges, including simulated monsters. Later, another anime-only arc forces the heroes to enter another virtual world, similar in concept but with a different set of rules. In both arcs, the bodies of the humans entering the virtual world are confined to special pods for the duration of their stay there.
The popular .hack multimedia franchise is based on a virtual reality
MMORPG ironically dubbed "The World"
The French animated series Code Lyoko is based on the virtual world of
Lyoko and the Internet. The virtual world is accessed by large scanners which use an atomic process which breaks down the atoms of the person inside, digitizes them and recreates an incarnation on Lyoko.
In 2010 Caprica a science fiction television series introduce a fully immersed virtual reality world that the main character ventures in.
Steven Lisberger's 1982 movie TRON was the first mainstream Hollywood picture to explore the idea. One year later, it would be more fully expanded in the
Natalie Wood film Brainstorm.David Cronenberg's film EXistenZ dealt with the danger of confusion between reality and virtual reality in computer games. Cyberspace became something that most movies completely misunderstood, as seen in The Lawnmower Man. This idea was also used in Spy Kids 3-D: Game Over. Another movie that has a bizarre theme is Brainscan, where the point of the game is to be a virtual killer. A more artistic and philosophical perspective on the subject can be seen in Avalon. One of the non-Sci Fi movies that uses VR as a story driver is 1994's Disclosure, starring Michael Douglas and based on the Michael Crichton book of the same name. A VR headset is used as a navigating device for a prototype computer filing system. There is also a film from 1995 called "Virtuosity" with Denzel Washington and Russell Crowe that dealt with the creation of a serial killer, used to train law enforcement personnel, that escapes his virtual reality into the real world. Written by William Gibson himself, Johnny Mnemonic uses extensive VR, depicting Keanu Reeves playing a "cyber-courier" (Johnny Mnemonic) who smuggles data in his brain. James Cameron's 2009 movie
Avatar depicts a future time when people's consciousness are virtually transported into biologically grown avatars.
Music videos
The lengthy video for hard rock band Aerosmith's 1993 single "Amazing" depicted virtual reality, going so far as to show two young people participating in virtual reality simultaneously from their separate personal computers (while not knowing the other was also participating in it) in which the two engage in a steamy makeout session, sky-dive, and embark on a motorcycle journey together.
Classic Virtual reality HMD with glove
In 1991, the company (originally W Industries, later renamed) Virtuality licenced the Amiga 3000 for use in their VR machines and released a VR gaming system called the 1000CS. This was a stand-up immersive HMD platform with a tracked 3D joystick. The system featured several VR games including Dactyl
Nightmare (shoot-em-up), Legend Quest (adventure and fantasy), Hero (VR
puzzle), Grid Busters (shoot-em-up). Virtual Reality I Glasses Personal Display
System is a visor and headphones headset that is compatible with any video input
including 3D broadcasting, and usable with most game systems (Nintendo,
PlayStation, etc.). Virtual Reality World 3D Color Ninja game comes with headset visor and ankle and wrist straps that sense the player's punches and kicks. Virtual
Reality Wireless TV Tennis Game comes with a toy tennis racket that senses the
player's swing, while Wireless TV Virtual Reality Boxing includes boxing gloves that the player wears and jabs with. Bob Ladrach brought Virtual Knight into the major theme park arcades in 1994. Aura Interactor Virtual Reality Game Wear is a chest and back harness through which the player can feel punches, explosions, kicks, uppercuts, slam-dunks, crashes, and bodyblows. It works with Sega Genesis
and Super Nintendo.
In the Mage: The Ascension role-playing game, the mage tradition of the
Virtual Adepts is presented as the real creators of VR. The Adepts' ultimate objective is to move into virtual reality, scrapping their physical bodies in favour of improved virtual ones. Also, the .hack series centers on a virtual reality video game. This shows the potentially dangerous side of virtual reality, demonstrating the adverse effects on human health and possible viruses, including a comatose state that some players assume.
Metal Gear Solid bases heavily on VR usage, either as a part of the plot (particularly Metal Gear Solid 2 which focuses on the blur between reality and
virtual reality), or simply to guide the players through training sessions. In System Shock, the player has implants making him able to enter into a kind of cyberspace. Its sequel, System Shock 2 also features some minor levels of VR. In Black and White users could download a patch to use the P5 glove to control the game.
Attractions
The developer of theme park style attractions using Virtual Reality technology was a major part of the development of the hardware — moving beyond simulation towards an immersive entertainment experience. Of all these developments, the Walt Disney 'DisneyQuest' venue is the major conceptual application — still operational in 2009. Making Virtual Reality attractions mobile has also been on the forefront of their consumer appeal. As the technology improves and becomes more mainstream, various business and corporate events employ Virtual Reality providers to attract business and entertain their employees and guests.
Fine Art
David Em was the first fine artist to create navigable virtual worlds in the 1970s. His early work was done on mainframes at III, JPL and Caltech. Jeffrey Shaw explored the potential of VR in fine arts with early works like Legible City (1989), Virtual Museum (1991), Golden Calf(1994). Canadian artist Char Davies
created immersive VR art pieces Osmose (1995) and Ephémère (1998). Maurice Benayoun's work introduced metaphorical, philosophical or political content, combining VR, network, generation and intelligent agents, in works like Is God
Flat (1994), The Tunnel under the Atlantic (1995), World Skin (1997). Other pioneering artists working in VR have include Luc Courchesne, Rita Addison,
Knowbotic Research, Rebecca Allen, Perry Hoberman, Jacki Morie, and Brenda Laurel. All mentioned artists are documented in the Database of Virtual Art.
A side effect of the chic image that has been cultivated for virtual reality in the media is that advertising and merchandise have been associated with VR over the years to take advantage of the buzz. This is often seen in product tie-ins with cross-media properties, especially gaming licenses, with varying degrees of success. The NES Power Glove by Mattel from the 1980s was an early example as well as the U-Force and later, the Sega Activator. Marketing ties between VR and video games are to be expected, given that much of the progress in 3D computer graphics and virtual environment development (traditional hallmarks of VR) has been driven by the gaming industry over the last decade. TV commercials featuring VR have also been made for other products, however, such as Nike's "Virtual Andre" in 1997, featuring a teenager playing tennis using a goggle and gloves system against a computer generated by am co-operation..
Health care education
While its use is still not widespread, virtual reality is finding its way into the training of health care professionals. Use ranges from anatomy instruction to
surgery simulation. Annual conferences are held to examine the latest research in utilizing virtual reality in the medical fields.
Therapeutic uses
The primary use of VR in a therapeutic role is its application to various forms of exposure therapy, ranging from phobia treatments, to newer approaches to treating PTSD. A very basic VR simulation with simple sight and sound models has been shown to be invaluable in phobia treatment (notable examples would be various zoophobias, and acrophobia) as a step between basic exposure therapy such as the use of simulacra and true exposure. A much more recent application is being piloted by the U.S. Navy to use a much more complex simulation to immerse veterans (specifically of Iraq) suffering from PTSD in simulations of urban combat settings. While this sounds counterintuitive, talk therapy has limited benefits for people with PTSD, which is now thought by many to be a result of changes either to the limbic system in particular, or a systemic change in stress response. Much as in phobia treatment, exposure to the subject of the trauma or fear seems to lead to
