virtual reality

VIRTUAL REALITY

What is Virtual reality?Virtual Reality is a computer generated, multi-sensory information program which tracks a user in real time i.e. computer system is used to create an artificial world in which the user has the impression of being in that world ,with the ability to navigate through and manipulate objects in that world.

History of VR In 1950s, flight simulators were built by US

Air Force to train student pilots. In 1965, a research program for computer

graphics called “The Ultimate Display” was laid out.

In 1988, commercial development of VR began.

In 1991, first commercial entertainment VR system "Virtuality" was released.

Immersive Augmented Projected Window on a world

system(desktop)

Types of Virtual Reality

Immersive VR In a completely immersive system

, the user becomes part of the simulated world , rather than the simulated world being a feature of the user's own world.

Display devices like head-mounted display and stereo spectacles ; provide a 3-D virtual space in user's vision.

The first “immersive VR systems” have been the flight simulators where the immersion is achieved by mixture of real hardware and virtual imagery.

Augmented VR Augmented reality (AR) is a term for a live

direct or an indirect view of a physical, real-world environment whose elements are augmented by computer-generated sensory input, such as sound or graphics, haptic feedback.

Augmented reality does not create a simulation of reality. Instead, it takes a real object as the foundation and incorporates technologies that deepen a person’s understanding of the subject.

AR technology includes head-mounted displays and virtual retinal displays for visualization purposes, and construction of controlled environments containing sensors and actuators.

Projected VR The superimposing of physical reality

windows onto a virtual reality environment , such that participants of the virtual reality also see the physical reality object.

e.g. A The virtual environment is projected onto a large display on a single surface or a multiple projection “CAVE” from different directions, which can serve a group of people viewing the same content simultaneously.

Desktop VR Desktop-based virtual reality

involves displaying a 3-dimensional virtual world on a regular desktop display without use of any specialized movement-tracking equipment.

It is cost-effective when compared to the immersive VR.

However they lack the immersion quality, Because there is no sense of peripheral vision, limiting the user's ability to know what is happening around them.

Devices used in VR Technology HMD(Head Mounted Display)

A head-mounted display is a device, worn on the head that has a small display optic in front of one eye (monocular HMD) or each eye (binocular HMD) to reproduce a stereoscopic vision.

Training with HMDs involve a wide range of applications from driving, welding and spray painting, flight and vehicle simulators, dismounted soldier training and medical procedure training.

Haptic technology is a tactile feedback technology involving that the man-machine interface system should be capable of recording the movements of the human hand and also of replicating virtual forces.

E.g. is Cyber Grasp: It is a haptic feedback interface that enables; users are able to explore the physical properties of computer-generated 3D objects and manipulate them in a simulated 'virtual world.'

Haptic interfaces and

tactile feedback

CAVE (Cave Automatic Virtual Environment) Surround-screen, surround-sound, projection-based VR

system. Illusion of immersion is created by projecting 3D computer

graphics into a cube composed of display screens that completely surround viewer.

coupled with head and hand tracking systems. Sound system provides audio feedback. Sensors within the

room track the viewer's position to align the perspective correctly.

Viewer explores virtual world by moving around inside cube and grabbing objects. 

3D SCANNER A 3D scanner is a device that analyses a

real-world object or environment to collect data on its shape and possibly its appearance (i.e. colour). The collected data can then be used to construct digital, three dimensional models.

They are extensively used for the entertainment industry in the production of movies and video games , design , documentation of cultural artefacts involved in the design.

BOOM The BOOM (Binocular Omni-

Orientation Monitor) is a head-coupled stereoscopic display device.

Screens and optical system are housed in a box that is attached to a multi-link arm.

The user looks into the box through two holes, sees the virtual world, and can guide the box to any position within the operational volume of the device.

Head tracking is accomplished via sensors in the links of the arm that holds the box.

The Data Glove consists of a lightweight nylon glove with optical sensors mounted along the fingers which accurately and repeatedly measure the position and movement of the fingers and wrist.

Data gloves are commonly used in virtual reality environments where the user sees an image of the data glove and can manipulate the movements of the virtual environment using the glove.  

Data gloves

PROJECTORS and SHUTTER GLASSES

The Projector has extremely demanding requirements for its graphics hardware. It consists of 3D projection system, mirrors and projection walls.

Shutter glasses enable us to view virtual image or video more deliberately through them. Shutters in the glasses are synchronized with the display system using Infrared emitters.

Motion tracking Motion tracking uses a combination of

computer chips, sensors and cameras to record humans in motion and create digital doppelgangers that move the same way.

Designed for head and hand tracking in VR games, simulations, animations, and visualizations.

For example, Polhemus STAR*TRAK is a long range motion capture system that can operate in a wireless mode (totally free of interface cables) or with a thin interconnect cable.

Electromagnetic tracking systems measure and sense magnetic fields generated by running an electric current through three coiled wires .The system's sensors measure how its magnetic field affects the other coils. This measurement tells the system the direction and orientation of the emitter.

Acoustic tracking systems emit and sense ultrasonic sound waves to determine the position and orientation of a target. The system calculates the position and orientation of the target based on the time it took for the sound to reach the sensors.

Mechanical tracking systems rely on a physical connection between the target and a fixed reference point. E.g. is A BOOM display is an HMD mounted on the end of a mechanical arm. The system detects the position and orientation through the arm.

Applications of VR Rehabilitation and help to disable

peopleIt is also possible to create dialogue based on hand gestures between a deaf real human and a deaf virtual human using Sign Language. Muscular dystrophy patients can learn to use a wheelchair through VR.

PsychiatryWith the advent of realistic virtual humans, it will be possible to recreate situations in a Virtual World, immersing the real patient into virtual scenes. Therapists may also use VR to treat people who are afraid of heights.

Medicine With the simulation of the entire physiology of the human body , the effects of various illnesses or organ replacement will be visible. The surgeon using anHMD and Data Gloves may have a complete simulated view of the surgery. For medical students learning how to operate, the best way would be to start with 3D virtual patients.

Education and trainingThe most common example is the flight simulator . They have lower operating costs and are safer to use than real aircraft. They also allow the simulation of dangerous scenarios not allowable with real aircraft.

DesignMany areas of design are typically 3D for example, the design of a car shape, where the designer looks for sweeping curves and good aesthetics from every possible view.

Operations in dangerous environmentsWorkers in radioactive, space, or toxic environments could be relocated to the safety of a VR environment where they could 'handle' any hazardous materials without any real danger. Moreover, the operator's display can be augmented with important sensor information, warnings and suggested procedures.

Architectural visualizationIn this area, VR allows the future customer to “live” in his/her a new house before it is built. He/she could get a feel for the space,experiment with different lighting schemes, furnishings, or even the layout of the house itself. 

VR SOFTWARE VRML  (Virtual Reality Modeling Language)

standard language for interactive simulation within the World Wide Web. 

allows to create "virtual worlds" networked via the Internet and hyperlinked with the World Wide Web.

  Aspects of virtual world display, interaction and 

internetworking can be specified using VRML without being dependent on special gear like HMD.

  VR models can be viewed by Netscape or IE with a 

browser plug-in.

Multiverse (Freeware) 

Virtual Reality Studio ($100)

Sense8 World Tool Kit (WTK) (over $1000)

Autodesk Cyberspace Development kit (over $1000)

Software packagesavailable in market

CONCLUSIONVirtual Reality is at a critical design phase. The theories behind its design and operation are still being written. There are 61,400 international commercial companies producing VR. There are approximately 3,600 educational institutions which use VR.

Advantages of VR Visualization of complicated, large data

is helpful for understanding and analysis.

VR offers us a new way to interact with computer.

VR enables us to experience the virtual world that is impossible in real world.

VR is changing our life, eventually VR will increasingly become a part of our life.

Efforts byRABIA WADHWA