Survey Hardware (how they work)
Virtual Reality (VR) hardware • Input Devices • Output Devices • Virtual Reality System • 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
VR Input Devices Forceball • ball mounted on small, stationary platform • twist, squeeze, press down, pull up, and turn side to side • uses LEDs and photoreceptors inside the base to measure force Flying mouse • similar to mouse • becomes 6DOF sensor when lifted off the desktop • electromagnetic sensors built-in Dataglove • captures relative movement of fingers, thumb and wrist • allows the hand to grasp, move, or interact with virtual objects • includes position sensor Wand • similar to a flying mouse • lacks mouse ball • contains position-tracking sensor and designed to be held upright • 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
VR Display Devices 3-D Glasses • uses a red and blue colored lens to combine into stereoscopic Head-Mounted Displays (HMDs) • with head-tracking devices • LCD shutter glasses are synchronized to two alternating separate views of the same scene
Survey World Builders & Authoring Tools
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
Survey Virtual 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.
Programming Tools & Libraries • 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
Survey Agent & 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.