Hardware (how they work)

Survey

Virtual Reality (VR) hardware

input device - measures and records physical phenomena electronically, creating digital signals that the computer understands

output device - changes electronic signals into physical phenomena and provide sensible data 

virtual reality system - follows software instructions in assembling, processing and displaying all the data involved in creating a virtual world in real-time

Input DevicesOutput DevicesVirtual Reality System

VR Input Devices

six degrees of freedom(6DOF) 2DOF devices - measure movements along

the X and Y axes 6DOF devices - measure movements along

the X, Y, Z axes AND orientation of an object Examples of 6DOF devices - flying mouse,

wand, forceball and dataglove

Flying mouse similar to mousebecomes 6DOF sensor when lifted

off the desktopelectromagnetic sensors built-in

Wandsimilar to a flying mouselacks mouse ballcontains position-tracking sensor

and designed to be held upright 

Forceballball mounted on small, stationary

platformtwist, squeeze, press down, pull up, and

turn side to sideuses LEDs and photoreceptors inside the

base to measure force

Dataglovecaptures relative movement of fingers,

thumb and wrist allows the hand to grasp, move, or

interact with virtual objectsincludes position sensor

VR Display Devices

3-D Glassesuses a red and blue colored lens

to combine into stereoscopic

Head-Mounted Displays (HMDs)with head-tracking devicesLCD shutter glasses are synchronized to two

alternating separate views of the same scene

World Builders & Authoring Tools

Survey

What is an authoring tool? An authoring tool is a tool to help

you in building something, in this case, a VR world

There are a lot of authoring tools out there and one of the most common tool used and found is the Notepad (or any other text editor)

Other Authoring Tools

Any 3D modeler (that may or may not support exporting to VRML 97 format) Example : 3D Studio Max,

Lightwave Studio, Maya World builders that are specific to

VRML Example : Cortona, Interactive

VRML World Builder

Advantages vs. Disadvantages Text Editor

Advantages : Able to have full control over the

model Building sleek and slim codes Gain better knowledge and port it

to world builders Disadvantages :

Long coding times for large worlds Human typo errors

Advantages vs. Disadvantages Generic 3D Modelers

Advantages : Wide variety of built in tools More comprehensive then most

world builders Disadvantages :

Not optimised for web development

Advantages vs. Disadvantages VRML World Builders

Advantages : Optimised for web Most are able to port to the web

which can be viewed directly (to HTML format)

Disadvantages : Not very comprehensive Sometimes might generate errors

which are hard to debug

How does it work?

Records down all vertices and positions of all objects in the scene

Records down other info like material and lighting

File uses .wrl extension Other formats can be converted to

VRML 97 format by using 3rd party softwares

Future of Authoring Tools X3D-Edit is a new tool for

Extensible 3D Graphics (Virtual Reality is one of it)

X3D-Edit uses XML tagset defined by the X3D Compact Document Type Definition (DTD) in combination with Sun's Java, IBM's Xeena XML editor, and an editor profile configuration file

SurveyVirtual Reality Programming, scripting, etc

Programming Tools & Libraries OpenGL

Needs no introduction DirectGraphics

A component of DirectX Only works on Windows

Java3D Java-based Less mature than DirectX and

OpenGL

Programming Tools & Libraries CAVE

Full-fledged projection-based VR system

CAVE library is the SDK GHOST SDK

Toolkit for developing touch-enabled applications.

Programming Tools & Libraries VR Juggler

Library used as framework for app development

Controls rendering, VR devices, projection, etc.

Not a visual development environment.

Java (2) SDK v 1.3 standard tool used automatic installation java3D as an extension to libraries

MS Visual J++ has to be hacked into to enable

java3D might cause a problem

Programming Tools & Libraries

Activate - VRML2 Toolkit for C/C++ Developers allow adding VRML97 files into MS

Windows products needs a C++ compiler

VIPER: The NIST VRML97 Parser analyses and checks for error in

VRML97 files

Programming Tools & Libraries

SurveyAgent & Avatars Technology

AVATARS

An image representing a user in a multi-user virtual reality space.

Creature in a virtual reality world that has been endowed with life and may interact with each other.

Used for training, simulation, public speaking and cyber conference.

INTELLIGENT AGENTS

A virtual being capable of carrying out a task towards a goal while requesting and receiving advice in human terms.

Used mainly for data mining such as in www.google.com and databases of companies.