The VirtuSphere looks a lot like a giant mouse ball, or hamster wheel. However, this human-computer interface device is anything but humourous. One of the great issues with immersive VR has always been allowing natural movement in enclosed spaces. The last attempt to allow for natural walking, the CirculaFloor, consisted of moving panels which detected foot pressure, and detached themselves from the path behind you, scooting forwards to catch your next footfall. A great idea, but limited your movement to a snail's pace.

VirtuSphere does not suffer from multiple moving parts. Users stand inside the main sphere, which itself rests on twenty-six detector-wheels, splayed out to allow for huge strides if necessary. Any movement inside the sphere, is picked up by these detectors - or as the company refers to them, docators - which work through ultrasonic detection of doppler motion, detecting the force and direction as the sphere rolls against them, and translating it directly into X, Y, Z, roll, pitch and yaw with extreme precision. Walk at any pace, jog, run, squat down and roll, the VirtuaSphere will pick up your precise movements, and translate them to the simulation in real time.

Because of the way it works, the system will even pick up small jumps - as bouncing in the sphere, and a slight roll in any given direction. Fall over, and the resultant movement of the sphere shows you some visual feedback - although admittedly it won't show you falling over, just shaking and moving back a bit.

The VirtuSphere is an input device only. Because of its construction and the way it is constantly moving, there is nowhere to back-project an image like you would in a CUBE, CAVE or hemisphere. The sphere makes up for this by employing a head mounted display unit or HMD for visual feedback. The sphere is supplied with a HMD device, although the manufacturer would not comment on the specs of this display unit. However, any HMD will work.

All positional changes are replicated immediately back to the HMD's display screen(s) for maximum immersion. Because of this, VirtuSphere environments predispose well to augmenting via haptic gloves, suits and the like as they have no physical elements to interfere beyond the sphere itself. Additionally, it is possible to mount the sphere inside a CAVE VR system, instead of using a HMD, and the two devices will sync happilly together.

VirtuSpheres are still very new - as of writing they have only recently entered the market - and so VirtuSphere systems are individually tailor-made to client specifications. The sphere itself flat-packs to a surprising degree for storage.

Images reproduced with permission, VirtuSphere

As the sphere does closely resemble a mouse or trackball taken to a huge scale, it is not actually that difficult to interface it to many existing applications. Several packages have also been custom-modified to work flawlessly with the sphere. These include the Cortona VRML browser from Parallel Graphics - one of a precious few VRML browsers that does not insist on Internet Explorer in order to run. Additionally, it will quite happilly hook up to a standard PC, Playstation or X-box, for immersive VR at home.

At a cost of $50,000 - $100,000usd for an installation, the VirtuSphere is not a cheap interface, and likely a little outside the average gamer's budget at the moment. However, like all new VR technologies, the price starts to drop as it begins to prove itself, and more are requested.