VIRTUAL

REALITY

Nowadays computer graphics is used in many domains of our life. At the end of the 20th century it is difficult to imagine an architect, engineer, or interior designer working without a graphics workstation.

These machines are equipped with better and faster graphics boards and their prices fall down rapidly. It allows to see the surrounding world in other dimension.But not enough: people always want more.

They want to step into this world and interact with it instead of just watching a picture on the monitor.

Virtual Reality (VR).

INTRODUCTION

HISTORY

1965 • Ivan Sutherland• The beginning of VR.

1982 •Bonnie Mac bird•The First Computer – Generated Movie

1983 •Myron Krueger•First Virtual Environment

1987 • Michael piller• Idea of Immersive VR.

1995 • Silicon Graphics• VR modeling Language

1999 • Larry and Andy• VR movie grosses $750M worldwide.

2004 • Facebook purchases a company that makes virtual reality headsets, Oculus VR, for $2 billion.

1950 • The concept of virtual reality is basically started

Virtual reality (VR) is not a new concept. A seminar paper by Ivan Sutherland that introduced the key concepts of immersion in a simulated world, The screen is a window through which one sees a virtual world.

The challenge is to make that world look real, act real, sound real, feel real .Sutherlands challenge interface metaphor to a synthesized world

Growing community of researchers and industries. virtual reality is seen as a way to overcome limitations of standard human-computer interfaces; virtual reality technology opens the door to new types of applications that exploit the possibilities offered by presence simulation.

What is Virtual Reality ?

2.RequirementsThe goal of virtual reality is to put the user in the loop of a real-time simulation, immersedin a world that can be both autonomous and responsive to its actions.The requirements for virtual reality applications are defined by analyzing the needs in termsof input and output channels for the virtual world simulator.

2.1 User inputWe Interact with the world mainly throughlocomotion manipulationWe communicate information mostly by means of voice,gestures, and facial expressions

Gestural communication as well as locomotion make full body motion analysis desirable, while verbal communication with the computer or other users.

2.2 Sensory Feedback

Our sense of physical reality is a construction derived as geometric, and dynamic information directly presented to our senses. The output channels of a virtual reality application correspond thus to our senses: vision, touch and force perception, hearing,smell, taste. Sensory simulation is thus at the heart of virtual reality technology.

2.3 Spatio-TemporalAbility to meet synchronization.Second, varying delays in the various output devicesWorse, synchronization errors also result from varying distances between user and devices. sacrifice synchronization to enable low-latency, audio-only communication.

VIRTUAL REALITY DEVICES

A variety of input devices allow the user to navigate through a virtual environment and to interact with virtual objects. Directional sound, tactile and force feedback devices, voice recognition and other technologies are being employed to enrich the immersive experience and to create more "sensualized" interfaces.

The sensors measure the bending angles of the joints of the thumb and the lower and middle knuckles of the others fingers, Attached to the back is a Polhemus sensor to measure orientation and position of the gloved hand. This information, along with the ten flex angles for the knuckles is transmitted through a serial communication line to the host computer.

THE DATA GLOVE

The Logitech 3D mouse Figure is based on a ultrasonic position reference array, which is a tripod consisting of three ultrasonic speakers set in a triangular position, emits ultrasonic sound signals from each of the three transmitters. These are used to track the receiver position, orientation and movement. It provides proportional output in all 6 degrees of freedom: X, Y, Z, Pitch, Yaw, and Roll..

3D MOUSE AND SPACE BALL

Wands, the simplest of the interface devices, come in all shapes and variations. Most io rate on-off buttons to control variables in a simulation or in the display of data. Others have knobs, dials, or joy sticks. Their design and manner of response a re tailored to the application. Fig 4. Wand Most wands operate with six degrees of freedom; that is, by pointing a wand at an object, you can change its position and orientation in any of six directions: forward or backward, up or down, or left or right.

WANDS

One of the most "immersive" virtual environments is the CAVE. It provides the illusion of immersion by projecting stereo images on the walls and floor of a room-sized cube. Cave Several persons wearing lightweight stereo glasses can enter and walk freely inside the CAVE. A variety of input devices like data gloves, joysticks, and hand-held wands allow the user to navigate through a virtual environment and to interact with virtual objects.

CAVE

•A darkened cubicle•Sense of being inside the v.environment•Burden less, free movement•Complete 3D effect•3D Crystal-eyes shuttering glasses•Future: Cave-to-cave teleconferences

BOOM

The Binocular Omni Orientation Monitor, or BOOM, is similar to a head-mount except that there's no fussing with a helmet. The BOOM's viewing box is suspended from a two-part, rotating arm. Simply place your forehead against the BOOM's two eyeglasses and you're in the virtual world. To change Fig 7. Boom your perspective on an image, grab the handles on the side of the viewing box and move around the image in the same way you would if it were real Bend down to look at it from below; walk around it to see it from behind. Control buttons on the BOOM handles usually serve as the interface although you can hook up data gloves or other interface devices.

Viewing box suspended from rotating arm

•Grab the handles and move around•More telepresenceas compared to HMDs

HEAD-MOUNTED DISPLAY

The head-mounted display (HMD) was the first device providing its wearer with an immersive experience. A typical HMD houses two miniature display screens and an optical system that channels the images from the screens to the eyes, thereby, presenting a stereo view of a virtual world. As a result, the viewer can look around and walk through the surrounding virtual environment.

•Simplest form of VR•Portable viewing screens•Projection of images•Response to head movements•Used in flight simulators

Haptic Interfaces

Haptic feedback interface enables user to actually "touch" computer-generated objects and experience force feedback via the human hand. The CyberGrasp is a lightweight, unencumbering force-reflecting exoskeleton that fits over aCyberGloveand adds resistive force feedback to each finger. With the CyberGrasp force feedback system, users are able to explore the physicalproperties of computer-generated 3D objects they manipulate in a simulated 'virtual world.'

Types of Virtual RealityNon-immersi

ve

Augmented

Reality

Immersive

systems

INTERNET BASED (VRML)

REAL TIME DIRECT OR INDIRECT VIEW OF A REAL WORLD

WORKSTATION + 3D INPUT AND

OUT PUT DEVICE

Non-immersive systems are the least immersive implementation of VR techniques Interaction with the virtual environment can occur by keyboards, mice and trackballs

Using the desktop system, the virtual environment is viewed through a portal or window by utilizing a standard high resolution monitor.

Non-Immersive systems

Augmented reality

•Stay in real world, but see simulated objects.•Augmented Reality can be used for training.•We define Augmented Reality (AR) as a real-time direct or indirect view of a physical real-world environment that has been enhanced by adding virtual computer-generated information to it.•Augmented Reality aims at simplifying the user’s life by bringing virtualinformation not only to his immediate surroundings, but also to any indirect view of the real-world environment, such as live-video stream.

Immersive systems

create sense o f immersion

• In a virtual reality environment, a user experiences immersion, or the feeling of being inside and a part of that world. •He is also able to interact with his environment in meaningful ways.• The combination of a sense of immersion and interactivity is called. Telepresence.In other words, an effective VR experience causes you to become unaware of your real surroundings and focus on your existence inside the virtual environment

Virtual Reality Application OPERATIONS IN DANGEROUS ENVIRONMENTS

There are still many examples of people working in dangerous or hardship environments that could benefit from the use of VR-mediated teleportation.

Workers 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 using teleoperation or telepresence.

SCIENTIFIC VISUALIZATION Scientific Visualization provides the researcher with immediate

graphical feedback during the course of the computations and gives him/her the ability to 'steer' the solution process.

Application at NASA Ames Research Center is the Virtual Planetary Exploration. It helps planetary geologists to remotely analyze the surface of a planet. They use VR techniques to roam planetary terrains.

MEDICINE Until now experimental research and education in medicine

was mainly based on dissection and study of plastic models. Computerized 3D human models provide a new approach to research and education in medicine. Experimenting medical research with virtual patients will be a reality.

We will be able to create not only realistic looking virtual patients, but also histological and bone structures. With the simulation of the entire physiology of the human body,

EDUCATION AND TRAINING

The most common example is the flight simulator. This type of simulator has shown the benefits of simulation environments for training. 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.

VRML – Virtual Reality Modelling Language•Purpose: The Virtual Reality Modeling Language is a file format for describinginteractive 3D objects and worlds. VRML is designed to be used on the Internet, intranets, and local client systems. VRML is also intended to be a universal interchange format for integrated 3D graphics and multimedia.• Use: VRML may be used in a variety of application areas such as engineering and scientific visualization, multimedia presentations,entertainment and educational titles, web pages, and shared virtual worlds.•VRML is capable of representing static and animated dynamic 3D and multimedia objects with hyperlinks to other media such as text,sounds, movies, and images.• VRML browsers, as well as authoring tools for the creation of VRML files, are widely available for many different platforms.Some nodes are container nodes or grouping nodes A VRML file is essentially a collection of Objects called Nodes various shapes• Nodes are arranged in hierarchical structures called scene graphs.

VRML is a language for describing 3-D image sequence and possible users.For ex. You can view a room and use controls to move the room as you would experience it

. Many different fields can use VR as a way to train students without actually putting anyone in harm's way.

• This includes the fields of medicine, law enforcement so on.e, a VR community on the Internet, exploring virtual cities as well as more fanciful environments.

• VR also helps patients recover from stroke and other injuries. Telepresence applications

•Doctors are using VR to help reteach muscle movement such as walking and grabbing as well as smaller physical movements such as pointing.

•The doctors use the malleable computerized environments to increase or decrease the motion needed to grab or move an object.

ADVANTAGES

DISADVANTAGE The hardware needed to create a fully immersed VR experience is still cost prohibitive.(compare with car cost) Programmers are still grappling with how to interact with V.E

Addiction cause Possible impacts on real body

One worry is that as VR environments become much higher quality and immersive, they will become attractive to those wishing to escape real life.

Training with a VR environment does not have the same consequences as training and working in the real world.

This means that even if someone does well with simulated tasks in a VR environment, that person might not do well in the real world. Psychological damage; identity problems

Science fiction literature and film have explored a range of futuristic VR technologies and the experiential opportunities they may offer.

Virtual experience and virtual identities via memory implants .

Recording and sharing experiences.

Games scenarios.

Use of VR for deception and control

Virtual reality has been heavily criticized for inefficient method for navigating Non-geographical informationAnother obstacle is the headaches,sickness due to eye strain.

RSI can also Result from repeated use of the handset gloves. It may require specialized training to operate

FUTURE POSSIBILITESCHALLENGE POSSIBILITES

Though the disadvantages of Virtual reality can disturb the human’s perception ability, it’s advantages in different fields makes it user friendly.

The sole objective of virtual reality is to give the user an environment as realistic as possible and a thrilling sensory experience. The technology of virtual reality is advancing rapidly and it won't be long before it becomes a most exciting source of entertainment in our homes.

Web is very suitable for VR applications, but the proper technology is not yet there

CONCLUSION