The Daves Rave about the Cave

You've all seen virtual reality simulators in television, magazines, etc but have you ever gotten the chance to actually see one with your own two eyes? While the University Of Illinois is having its Engineering Open House, Beckman institute opens its doors to the public to view some of their current projects and NCSA (the National Center for Supercomputing Applications). Although one of the most popular exhibits are the tours given by the Association Of Computing Machinery of NCSA's CAVE.

-What is this CAVE?
The (CAVE Automatic Virtual Environment) is a walk-in projection based VR system that allows a person first perspective real time virtual reality interaction. The virtual environment is constructed of four high definition projection screen 'walls' arranged in a open-cube fashion.

-Is the system in 3D?
Absolutely, the cave system is based on a six-degree tracking system allowing the 'controller' to look in any direction or move to anyplace in the simulation and have the perspective altered to fit their location. This allows one to pop your head into a floating sphere and have a look at the inside, or duck under it and check out what the bottom looks like. The CAVE systems also allow a true 3D effect without badly distorting colors or images. By shifting an image back and forth slightly between two perspectives, the CAVE can generate enough information to make you brain see three dimensions. This is accomplished by a pair of two panel LCD glasses that receive a signal to switch from blacking out the left panel, to blacking the right. Add a high-end speaker system for audio feedback and the CAVE system will always generate a perfect 3D environment.

-How do you interface with the environment?
Well since most people don't like holding a keyboard in the CAVE, another type of interface had to be developed. Using the same six-degree rotation and position tracking system, almost any device can be interfaced with enough tweaking, but the default interface devised was the wand. This wand allows the 'controller' to tilt, roll, pitch, and move in all directions as well as giving a place to have a few buttons to do with as the programmers please. This device sometimes gives the CAVE a real video game feel being much like a joystick.

-What does this thing run on?
Only the best. A silicon graphics Onyx with four infinite reality engines to power the four walls of the CAVE. Various other SGIs are used as consoles and development stations. The walls are projected by Electrohome Marquis 8000 projectors, that throw full-color workstation fields (1024x768 stereo) at 96 Hz onto the screens, giving approximately 2,000 linear pixel resolution to the surrounding composite image. Computer-controlled audio provides a sonification capability to multiple speakers. A user's head and hand are tracked with Ascension tethered electromagnetic sensors. Stereographics' LCD stereo shutter glasses are used to separate the alternate fields going to the eyes. A couple big mirrors, expensive screens, and a 30x20x13-foot light-tight room to top it all off.

-Where can I get tickets?
Follow the signs to Beckman's atrium. Tours are 9-12 and 1-3 during EOH.