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Haptics, And Phantoms, And CAVEs – Oh My!

In an effort to bring more and more realism to the virtual world, VR developers get increasingly more creative. Devices have been invented that simulate tactile feedback (a fancy name for touch) and force feedback. Together these are called haptic devices. The most notable commercially available force feedback product is called Phantom, and touch feedback devices are usually some permutations of virtual gloves – DataGlove, CyberGlove, etc. (See Related Links for more information about these devices.) If you are holding a virtual ball in your hand, for example, a tactile device will let you feel how smooth or rough its surface is, whereas a Phantom will let you feel how heavy it is. Gloves, by the way, are also tracking devices, because they let you feel the virtual objects you are touching (by simulating pressure and tingling sensation on your hand), at the same time feeding information about position of your fingers back to the computer. Details of how haptic devices work are outside the scope of this article.

Many VR input/output devices can be brought together in an amazing facility called CAVE (stands for Computer-Aided Virtual Environment). It is truly the ultimate VR experience. According to Michael Bramwell, in his article Virtual environments provide greater immersion into the world of scientific data: "A CAVE is a multi-person, room-sized, high-resolution, 3-D video and audio environment. Graphics are projected in stereo onto the walls and the floor, and viewed with stereo glasses. As a viewer wearing a position sensor moves within the display boundaries, the correct perspective and stereo projections of the environment are updated by a supercomputer, and the images move with and surround the viewer. Hence stereo projections create 3-D images that appear to have a continuous presence both inside and outside the projection room. To the viewer with stereo glasses, the projection screens become transparent and the 3-D image space appears to extend to infinity. For example, a tile pattern could be projected onto the floor and walls such that the viewer sees a continuous floor extending well outside the boundaries of the projection room. Three-dimensional objects such as tables and chairs would appear to be present both inside and outside the projection room. The result is that the viewer believes these objects are really there until he or she tries to touch them or walk beyond the boundaries of the projection room. In many Caves, there are rips and tears on projections screens where viewers have forgotten to be careful when walking within these invisible boundaries."