User requirements when interacting with virtual objects

The evolution of virtual reality is gradually moving towards the capabilities described by Meredith Bricken (1992): “In a virtual world, we are inside an environment of pure information that we can see, hear and touch. The technology itself is invisible, and carefully adapted to human activity so that we can behave naturally. We can create any imaginable environment and we can experience entirely new perspectives and capabilities within it.” That is, in a properly designed virtual environment, there is no user interface to design as the interaction with the environment should be as natural as interacting with the `real world´. So far, however, technology has concentrated primarily on the auditory and visual modalities. Stereoscopic, immersive displays are beginning to provide realistic images for the eyes, and high-fidelity stereoscopic sound provides the ears with sound that is localised in space. However the issues surrounding the manipulation of virtual objects are just beginning to be addressed. In this presentation the authors discuss this third sense of `touch´ (although there is more to manipulating objects than just touch) and describe what advantages this provision of sensory feedback will have for some virtual environments