Proprioception and Natural Walking in Navigation Metaphors for Virtual Environments

A Virtual Environment (VE) is a computer-generated setting in which a participant is presented with simulated conditions that can be controlled to varying degrees. These simulations serve several purposes, including research, entertainment, and training. VE technology has already been shown to have applications in immersion therapy for phobia patients (Harris, Kemmerling, and North, 2002), and may be a benefit in physical rehabilitation as well (Matsuoka, Allin, and Klatzky, 2002). Loomis, Blascovich, and Beall (1999) explore the use of VE technology for social psychology, as the control over VEs provides a solution to the difficulties in recreating real social interaction with a simulated audience. The primary benefit of using VEs in research is the degree of control over the environment that is afforded to the researchers. In theory, VEs should be able to bridge the gap between internal and external validity. While they can display an accurate representation of the real world, they are created and controlled by researchers, and so they effectively become a laboratory (Loomis et. al., 1999). VEs can vary across several dimensions, including participant control over the field-of-view and orientation, the ability to manipulate objects in a scene, the ability to change location in a scene, and the degree to which the displays used are immersive. A VE display is said to be completely immersive if all input to a given sense originates from the virtual simulation. For example, a head-mounted display (HMD) is visually immersive because it blocks all visual input from outside the VE and presents the participant with a display that is entirely controlled by the VE. In addition to immersion, VEs are capable of providing the participant with a subjective feeling of " presence, " or the sensation of being in one place or environment, even when one is physically situated 1 in another (Witmer and Singer, 1998). For VEs, the notion of presence refers to a displacement of a participant's self-perception from the real world to the computer-Often referred to as virtual reality (VR), most VEs are created using a combination of visual and auditory displays. There are two primary methods of presenting a virtual environment visually, each with benefits and shortcomings. A HMD-based virtual environment is created by placing a small screen in front of each eye. The screens are generally a part of a visor that is worn on the head resulting in a visual display that is completely immersive. …