Virtual Reality did not come to pass partly because the devices employed in the interaction, the huge head-mounted displays, encumbered its users. But more importantly, main
assumption of the virtual reality paradigm, namely that full computer immersion in virtual environments could be achieved by stimulating the visual sense only, just did not hold.
However, VR technology did not vanish, rather it has been employed in creating environments that accommodates more, or all of the human body, and car and flight simulators are current examples of this.
One implementation of VR technology that has been particularly successful is CAVEs, where the virtual environment is projected, or mapped onto, a physical three-dimensional space.
A CAVE (Cave Automatic Virtual Environment) is an interactive room, where three to six of the walls are presenting virtual information to the user. The virtual environment is created based on the user's position, his movement and hand gestures. It is a surround-screen system, where the body of the operator is what actuates interaction.
The first CAVE was finished in early 1992 by the Electronic Visualization Laboratory (University of Illinois, Chicago,) and was presented as a virtual reality theater (Cruz-Neira, Sandin, DeFanti, Kenyon and Hart 1992). The environment consisted of 4 interactive screens (three walls plus the floor,) and a surround sound system. The system was presented with a range of rather specialized programs optimized for the CAVE, among them a
three-dimensional weather system map, a brain-surgery planning software, a program for exploring the evolving universe, and a molecule modeling software. The first CAVE was thus very specialized in use, but demonstrated an stunning ability to visualize and scale the very small or the very big, to human size, allowing the user to be immersed in, exploring and
manipulating, micro and macro worlds previously removed from us.
The CAVE hardware interface comes in many versions and sizes, but each of them share a set of features. The illusion of immersion is generated by projecting stereoscopic computer images (high definition 3D) on the walls, where mapping and rendering software fits the video images to the exact dimensions of the space. The user employs 3D glasses to correctly interpret the layered image information, thus extending the notion of depth beyond the physical CAVE walls.
Through the use of hand gestures or hand-held control devices, the user can navigate through, and activate features presented within the virtual environment (see figure 5.4).
Fig. 5.4: Interacting in a CAVE environment.
As the 3D glasses are semi-transparent, the user can see himself in the interface, allowing the real to blend with the virtual. The user is mobile, he can walk within the CAVE, and his position is continuously tracked to project the a correct perspective to that of the users point of view. Several CAVEs are also equipped with a sound system, and utilize auditory feedback as part of the interaction. The first CAVE only supported single-user tracking and navigation, but later editions accommodate multi-use—although that usually means that one main user controls the viewpoint, while the other participants are enjoying the ride.
Programming and preparing a CAVE for a particular application requires an elaborate
mapping and configuration process, where each scene needs to be rendered to fit the particular responsive environment, thus making it less versatile or general in it use. However, they are becoming important visualization tools within scientific research, product development, and military training, and many CAVE systems are thus found within universities, and research and development departments of manufacturing companies. The immersive qualities of CAVE
systems are also explored in interactive art and games, where the artist has a unique opportunity to let the spectator become an exploring participant within the virtual environment. Artist and associate professor at the H.R Hope School of Fine Art at the
University of Illinois, Margaret Dolinsky, has produced several works for CAVE systems, and has a particular emphasis on the participative and collaborative art experiences. In her early work Dream Grrrls, developed by Dolinsky and programmer Grit Sehmish back in 1997 for the original CAVE system (Electronic Vizualization Library 2011), the participant is invited into a dream world populated by characters previously only presented through Dolinsky's oil paintings. Dolinsky seeks to present a dream world to a fully awake participant. Since the environment is presented from the users point of view, the act of sitting down or moving will alter the perspective of the environment, as we would expect in the real world. And as with dreams, the act of walking down an illuminated path, is no guarantee for it suddenly turning into a portal, that brings you to new and unexpected places. Trigger other cues, and gravity is no longer a consistent force, as the participants views himself being elevated through the virtual environment. Dream Grrrls extend and augments user perception, and allow us to do so by moving within the CAVE space, and navigating and manipulating virtual objects with a hand-held device.
The last decade has produced fewer pure CAVE interactive art works, partly because the elaborate process of image mapping and rendering. But I also reckon, that due to the
advancement within 3D modeling in the game industry, there is a demand for more realistic looking 3D virtual objects, to have satisfying immersive experiences.
And some evidence of the what the prominent use future CAVE systems will be, might be shed by the announcement of the Next Generation CAVE, also conceptualized by the Electronic Visualization Laboratory and funded by the Computer and Network Programs of the National Science Foundation in the U.S: “The Next-Generation CAVE Virtual
Environment, or NG-CAVE, is a scientific instrument that enables researchers to visualize data in a fully immersive 3D stereoscopic environment; it serves as the lense of a 'telescope' or 'microscope,' enabling them to see their e-science datasets that reside in cyberspace.”
(Electronic Visualization Laboratory 2009)
The CAVE systems do support several significant, and yet very specialized operations, due to the cost and physical space involved in setting up the system, and development of
applications. With the advent of Microsoft's Kinect in early 2009, a new kind of responsive environment were made available to the general man.