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COMPUTER GRAPHICS: What Is A CAVE and Why Use It?
Introduction


Image Courtesy of:http://www.evl.uic.edu/pape/CAVE/

Developed by the University of Illinois, the CAVE premiered at the ACM SIGGRAPH 92 conference, and has achieved national recognition as a compelling display environment and earned the reputation as the “second way” to virtual reality in response to MIT’s head-mounted devices. It allows the user to be completely immersed in the application with 3 surrounding walls and a floor. The CAVE has historically been one of the finest VR devices to display VR. UIC has been developing lower end systems that will enable companies and universities to build VR devices without the one million dollar commitment the CAVE requires. These visualization devices in order of importance are the following:

CAVE
C-Wall
Passive Stereo Wall
ImmersaDesk

There are four different projection devices at UIC. In the Art and Design building, the Passive Stereo Wall, C-Wall, and the ImmersaDesk exist in an area called the Passion Pit. The Passive Stereo wall is 5' x 6' and requires lightweight passive glasses. The C-Wall is also passive stereo measuring 10-' x 12'. The ImmersaDesk, like the CAVE, is Active Stereo and requires cumbersome head mounted gear. There is currently only one CAVE at UIC, located on the first floor of the ESL building. The Passive Stereo wall is an excellent presentation device because viewers are not required to wear heavy glasses and it is more accessible than the CAVE.

More About The Cave

The CAVE is both a recursive acronym (Cave Automatic Virtual Environment) and a reference to "The Simile of the Cave" found in Plato's Republic, in which the philosopher explores the ideas of perception, reality, and illusion. Plato used the analogy of a person facing the back of a cave alive with shadows that are his/her only basis for ideas of what real objects are.

Physically, the CAVE is a metal frame outlining the edges of a 10x10x10 cube. Polymer plastic-like screens are stretched over the three vertical faces of the frame. You stand in the middle of this thing and wear shutter glasses. Outside of the cube there are four projectors pointing at the three polymer covered faces and one projector pointing down at the floor.
The refresh rate of the projectors is synched up with the flicker rate of the shutter glasses so that every other projected frame alternates between a left eye and right eye image. The shutter glasses block out the image not meant for the blocked out eye effectively supplying each eye with its own personalized customized 3d image.

You should take advantage of the opportunity to program for the CAVE. Although CAVEs are not widespread throughout the world because they cost close to one million dollars to build, the same scene graph can be used to run your application on a passive stereo system which can be built for under ten thousand dollars.

There are many VR projection devices, more can be read about them at the Fake Space Systems web site.

Computer Graphics & Urban Planning
  What is Virtual Reality?
  What is a CAVE and why use it?
  VR & the Web
  Current & Future state of VR
  Ongoing projects
   
Overview of Classes & Program
  Newspace versus EVL computers
   
Project Fundamentals
  Collect Data
  Construct Models
  Apply Textures
  Program Interactivity
  Output to Display Device