IntroductionTypesHistory Application Devices VRML

“Virtual reality is a way for humans tovisualize, manipulate and interact withcomputers and extremely complex data.”The technology attempts to immerse the userinto a computer generated world.The user interacts with the world and candirectly manipulate objects in the world.

Virtual reality systems attempt to create “presence”.Presence is the un-remarked sense of being in andreacting to the events in a place.It is un-remarked because for most of our consciouslives we know exactly where we are (at least we thinkso)

REAL WORLD

VIRTUAL WORLD

A computer generated world with which the user can interact

Interaction can vary from looking around to interactively modifying the world.

Immersion in an environment (real or virtual) isrelated to the quantity and quality of sensory datafrom that environmentImmersion in a virtual environment can be gauged bythe extent to which the computer shuts out sensationsfrom the real world and accommodates differentsensory modalities (vision, audio, haptic)

What is Immersion?

HISTORY

Year Person(s) Responsible Why it was important

1965 Ivan Sutherland The beginnings of VR

1977 Dan Sandin, Richard Sayre and Thomas Defanti Interaction through body movement

1982 Bonnie MacBird (Writer) The first computer- generated movie

1983 Myron Krueger First virtual environment

1984 William Gibson (His assistant) The term 'Cyberspace'

1987 Michael Piller (Writer) The Holodeck, idea of immersive VR

1992 Stephen King (Official Website) A look at the possible negative side of VR

1995 Silicon Graphics Virtual Reality Modeling Language

1999 Larry and Andy Wachowski Virtual Reality movie grosses $750M worldwide

Flight Simulators:1910 Mechanical Simulators1929 Concept for electronic simulators1945 Point light source projection(simulating runway lights)1955 Video Based systems

The Sensorama - Circa 1960A Cinematographic Experience3D ImaginaryContextual SmellsStereo SoundVibrationWind in the hairMotorcycle ride throughBrooklyn

History of VR 1970'sFirst film special effects using computer graphicsFirst video arcade games - pongData GloveSandin and Sayre bend-sensing glove 1977G.J. Grimes, patented a data entry glove 1983(assigned to Bell Telephone Labs)Polhemus Tracker (Raab et al 1979)

History of VR 1980'sSee through Head Mounted Display(Callahan (MIT) 1983)Commercial head-mounted displays(VPL Research and Autodesk 1989)Term "Virtual Reality" coined( Jaron Lanier VPL 1989)SGI Reality Engine (1989)

History of VR 1990'sFirst Applications of Virtual Reality inmedical teaching:Colonoscopy SimulationUpper GI tract endoscopy simulationImproved general purpose hapticdevices (Sensable)First attempts at simulation oflaparoscopy

ImmersiveAugmented Text-basedDesktop (Window on a World)Video Mapping

A type of VR in which the user becomes immersed (deeply involved) in a virtual world. it is also a form of VR that uses computer related components.

Text-based VR: when a reader of a certain text form a mental model of this virtual world in their head from the description of people , places and things.

Augmented VR: the idea of taking what is real and adding to it in some way so that user obtains more information from their environment.

A room with projections on all walls, floor and ceiling

The users wear shutter glasses to get a 3D view of the world.

The users are able to move and control the environment with some kind of input mechanism Camera Device in hand

"One must look at a display screen, as a windowthrough which one beholds a virtual world”.Ivan Sutherland 1965Conventional computer monitor(possibly stereo with shutter glasses)Realistic SoundSpecial input devices(In reality just simple computer graphics, but stillappropriate for many medical applications)

Window on the World - ColonoscopySimulation

Video Mapping Refers to systems where the usercontrols a virtual actor in a virtualworld.Some systems show the user (or asilhouette) inside the world, butmore commonly the view is of thevirtual world through the actor'seyes.Possible for medical visualisationand surgical simulation

Systems with head trackingUsing simple stereo devices there is one correctposition from which to view a scene. By tracking theuser's head, and computing the stereo image pairaccordingly a more accurate 3D image can be created.When applied to limited space around a simple screenthis is sometimes termed “Fish tank virtual reality”

Hands in the fish TankStereo displays can be constructedthat allow the user to put his ownhands into the fish tank, andpossibly interact with the imagethrough a haptic device.They have been applied tosimulating laparoscopic procedures.

Haptic DevicesOne of the maindifficulties in applyingthese techniques inmedicine is designinghaptic devices that arerealistic enough.They are expensive andapplication specific.

Immersa DesksThese devices use all thetechniques discussed sofar, but are scaled up.Some have draftingcapabilities, and are moresuited to applications inarchitecture than inmedicine.

Sensors and manipulators areremotely controlled by ahuman operatorSome spectacular success,such as the exploration of theTitanic.Applications including fire fighter robots andunmanned military vehicles.Proposed for endoscopic or robotic surgery,but not really required in practical.

Augmented RealityOverlaying a real image with segmented scan data forsurgeryComputer generated maps and data overlaid ontransparent head mounted displays.Adding computergenerated information tothe real world.

Visually appealing results are possible

ArchitectureTrainingMedicineEngineering and DesignE-CommerceEntertainmentManufacturing

An area in which virtual reality has tremendous potential is in architectural design. Already being created are architectural "walk-throughs" that allow designers and clients to examine homes and office buildings, inside and out, before they're built. With virtual reality, designers can interactively test a building before construction begins.

researchers are using virtual reality technology to create 3-D ultrasound images to help doctors diagnose and treat congenital heart defects in children

The medical application of VR was stimulated initially by the need of medical staff to visualise complex medical data, particularly during surgery and for surgery planning, and for medical education and training.

United States: The military used it as flight simulators to train pilots.

National Aeronautics and Space Administration (NASA) use VR technology to construct a model of the Hubble Space Telescope (HST) .in September, 1993, approximately 100 members of the NASA HST flight team received over 200 hours of training using the VR...

BOOM is a head coupled stereoscopic display device. Screens and optical system are housed in a box that is attached to a multi-link arm.

Head Mounted Displays (HMD):

was the first device providing its wearer with an immersive experience. Evans and Sutherland demonstrated a head-mounted stereo display already in 1965.

Most exciting is the ongoing development of VRML on the World Wide Web. In addition to HTML (Hypertext Markup Language), that has become a standard authoring tool for the creation of home pages, VRML provides three-dimensional worlds with integrated hyperlinks on the Web. Home pages become home spaces.

Not a programming language like c++ or java

Descriptive (rather than procedural) like HTML

File formats contains human readable and editable ASCII text