Keywords
Citation
Cawkell, T. (2003), "Understanding Virtual Reality", Journal of Documentation, Vol. 59 No. 4, pp. 483-486. https://doi.org/10.1108/00220410310485776
Publisher
:Emerald Group Publishing Limited
Copyright © 2003, MCB UP Limited
This book is very nicely presented with many photographs and diagrams, including 16 pages of colour plates in the centre. It is divided into three parts with the titles “What is virtual reality?’’, “Virtual‐reality systems”, and “Appendices”. Following an introduction and brief history in the first part, the second part deals with input and output interfaces and system functions with a discussion of future possibilities. In the appendix four major systems are described in detail. NICE, an educational system for children, CRUMBS, a tool for a scientific visualisation, BOEING WIRE BUNDLES, a system for helping with the assembly of wiring harnesses, and PLACEHOLDER for artistic exploration. The book concludes with 17 pages of references and a good index.
Attempts are made to define virtual reality (VR) on page 6 of Understanding Virtual Reality. A number of synonyms and other terms, including usage of the word “virtual” are discussed The authors say “trying to define it completely can result in complex philosophical discussions”. They themselves have difficulty with the differences between “mental immersion” and “physical immersion”. Like other IT developments, virtual reality receives so much hype that it has become difficult to define – sales departments think the phrase adds cachet to mundane equipment having little to do with VR.
The phrase “virtual reality”, often defined as “a computer simulated environment’’, is said to have been coined by Jaron Lanier in the early 1980s. William Gibson's (1984) publication Neuromancer, a science‐fiction book, has been and still is heavily cited in the VR and science‐fiction literature. It is a vision which fired people's imagination describing something very like the complex (see below) systems which are certainly not science fiction.
As Newby (1993) says “there is a body of VR that does not require a user to … spend a fortune on input and output devices”. One of the very first VR components to be developed was Sutherland's (1968) head‐mounted tracking device. Two years later Ivan Sutherland was credited with inventing on‐line graphics with his Sketchpad software developed while he was at MIT, using a TX‐2 machine, one of the first large machines to use transistors. It had a 320K memory – considered remarkable at the time. A second major component of a VR system is the Sayre glove, developed at the University of Illinois by Defanti in 1977, followed by the fibre‐optic glove.
For the purposes of this review I will call relatively inexpensive systems including a head mounted tracking device, a finger‐/hand‐tracking glove, computer and display “simple systems”. Relatively expensive systems of greater complexity will be called “complex” systems. This crude classification is not very satisfactory but it will do.
Simple systems
ARISTcovered VR in the early 1990s. “As the first ARISTchapter on virtual reality almost all aspects of VR since the mid‐1960s are covered in some detail”, says Newby (1993). VR is now finding its place in libraries. Borner et al. (2003) discuss a project that will use data from the Web of Science “to test a virtual library interface that maps data stored in digital libraries on to an information landscape”. A $3 million investment has been made to provide a virtual library system “for an extensive collection of online resources for Alabama's colleges, universities and public libraries” (Morgan, 2001). Visualisation systems – closely related to VR – are being reviewed in this journal (Cawkell, 2003).
Hollands and Trowbridge (1996) describe an application showing the obvious advantage of being able to practice in a simulated rather than in a real environment In this medical application a fully‐functional simulation of the human knee is created which “provides the ability to model any pathology and carry out a wide range of operations including surgical reconstruction … the first phase of the simulation project … for a trainee surgeon to practise navigating round the knee, identifying significant landmarks and rehearsing standard inspection routes”.
Chen's VR work (Cawkell, 2003) describes displays with 3D effects on a single computer screen using special software such as Pathfinder with no “electronic clothing” – an example of a simple system. The phrase “electronic clothing” reminds me of another simple system application – “virtual fashion” as described by Gray (1998) from Nottingham Trent University. This demonstrates the potential of VR in a very different kind of application: “Be your own model in a synthetic world where everything off the rack is accustomed to it”, says the subtitle. An important aspect of VR in this field is the capability of simulating “dynamic drape”. The author says “the computer modelling of cloth drape has been discussed in a good many learned papers, and it has achieved a certain measure of success … when cloth is modelled as a physical object … every encounter of a fabric with the underlying object and with itself must be computed and then portrayed on screen in graphical form” (Gray, 1998). The objective here is to simulate the appearance of a garment as demonstrated by a mannequin walking along a catwalk:
It is not yet possible to perform this type of calculation in real‐time and therefore an animated fashion show with fully modelled cloth is not yet feasible (Gray, 1998).
Since Gray's paper was written, research on this topic has continued, but I have not been able to find any information about solutions. However, during a search the versatility of VR became obvious. A wide range of different applications are discussed in Roehl (1997) and Mortlock et al. (1997). With reference to archaeology, Roehl says “Rather than trying to describe the excavated site using words or rough sketches, the entire scene can be reconstructed in three dimensions and explored interactively”. Moving towards complex systems, Mortlock et al. (1997) are interested in the modelling of virtual humans which occupy much less bandwidth during video conferencing then do real humans. Virtual humans are sometimes called “avatars” – originally meaning “the incarnation of a Hindu deity in human form”, but used in VR as meaning “a representation of a user”. Mortlock et al. (1997) also discuss the development of MPEG4 – a standard covering the integration of text and graphics, face and body animation, texture coding and so on.
Complex systems
Understanding Virtual Reality deals mainly with complex (my classification, not the author's) VR, described on page 13 as:
In view of such complexity this review can only hope to convey a general impression of these systems – for a better understanding, this book, which discusses the details in a reasonably non‐technical manner, needs to be read. A frequently‐mentioned system called CAVE (CAVE Automatic Virtual Environment (Department of Psychology, Write State University, 2001)) shows that complex VR on a grand scale, first implemented at the University of Illinois, is an expensive business.QUOTEA medium composed of interactive computer simulations that sense the participant's position and actions and replace or augment the feedback to one or more senses, giving a feeling of being mentally immersed or present in the simulation – a virtual world.
A digression – CAVE at University College, London
At least one CAVE – at University College, London – has been installed in the UK (Department of Computer Science, University College, London, n.d.). UCL received a grant of nearly £1 million towards its cost so UK CAVES are rather scarce. The computer alone – an Onyx Reality Engine – and associated equipment cost about £400,000. Never mind – Professor Mel Slater tells me that you may hire the system for £500 an hour.
The UCL system embodies facilities including:
Studio‐pair images seamlessly projected in real‐time on three walls and the floor, while 8‐channel audio is presented from speakers at each corner. When viewed through lightweight shutter glasses, the left/right stereo images are presented separately to the left and right eyes respectively, producing the illusion of 3D images appearing both within and beyond the walls. Low‐latency head tracking allows perspective‐correct visualisation and auralisation, while other tracking devices may be used for navigation through and manipulation of the environment (Department of Computer Science, University College, London, n.d.).
This elaborate Virtual Environments Laboratory is used for applications in architecture, engineering design, medicine, and a variety of projects in computer science.
To find out more, refer to Slater (2002) as a source author in the Web of Science and click on “Related records” to find articles that have references in common with Slater's piece. The specialised erudite nature of this aspect of the subject does not prevent other aspects from being thus revealed – for instance “A survey of usability evaluation in virtual environments. Classification and comparison or methods”, and “Immersive television”.
Returning to the book …
The component parts of complex VR used in CAVE and other systems are described in Understanding Virtual Reality. The major components consist of body‐position trackers, helmets for tracking the movement of the head to follow the projection being viewed and to enable rendering to be implemented (see Cawkell, 2003), and gloves for sensing hand movements with finger positions also conveying the sense of touch (haptics) – for example, by sensing the amount of force required to move or deform an object. The problems associated with achieving realism with projected displays, the control of wall‐projected images and so on in complex systems are described in the book.
The blurb on the back of the book correctly states that Understanding Virtual Reality arrives at a time that it is possible to develop and deploy meaningful, productive virtual reality applications”. VR is a specialised subject but, disregarding current hype, it is flourishing. If you want to know more, this book is highly recommended.
References
Borner, K., Dillon, A. and Dolinsky, M. (2003), “Lvis: a smart virtual reality interface to digital libraries”, available at: www.Indiana.edu/∼uits/hpnap/projects/borner (accessed 3 February 2003).
Cawkell, T. (2003), “Book review: Chen, C., Mapping Scientific Frontiers: The Quest for Knowledge Visualization, Springer, Heidelberg, 2002”, Journal of Documentation, Vol. 59 No. 3, pp. 364‐9.
Department of Computer Science, University College, London (n.d.), “UCL immersive Virtual Environments Laboratory, project summary”, available at: www.cs.ucl.ac.uk/brandnew/research2/immersivevrlab_project_summary (accessed 3 February 2003).
Department of Computer Science, University College, London (2001), “Virtual environment”, available at: www.psych.wright.edu/facilities/veritas (accessed 3 February 2003).
Gibson, W. (1984), Neuromancer, Ace Books, New York, NY.
Gray, S. (1998), “Virtual fashion”, IEEE Spectrum, Vol. 35 No. 2, pp. 19‐25.
Hollands, R.J. and Trowbridge, E.A. (1996), “PC‐based virtual reality arthroscopic surgical trainer”, in Proceedings of Simulation in Synthetic Environments, New Orleans, LA, pp. 17‐22.
Morgan, J. (2001), “Turning a dream into a virtual reality of statewide information sharing”, Computers in Libraries, Vol. 21 No. 1.
Mortlock, A., Machion, D., McConnell, S. and Sheppard, P. (1997), “Virtual conferencing”, BT Technology Journal, Vol. 14 No. 4, pp. 120‐9.
Newby, G.B. (1993), “Virtual reality”, in Williams, M.E. (Ed.), Annual Review of Information Science andTechnology. Vol. 28: Learned Information, Medford, NJ, pp. 187‐229.
Roehl, B. (1997), “Virtual archaeology: bring new life to ancient worlds”, available at: www.mosaic.infobyte.it/news/press_review/180 (accessed 14 February 2003).
Slater, M. (2002), “Presence and the sixth sense”, Presence, Teleoperators and Virtual Environments, Vol. 11 No. 4, pp. 435‐9.
Sutherland, I.E. (1968), “A head‐mounted three dimensional display”, in Proceedings of the AFIPS Conference, San Francisco, CA, pp. 757‐64.