Design and Evaluation of Methods for Motor Exploration in Large Virtual Environments with Head-Mounted Display Technology
Virtual environments provide people with the opportunity to experience environments remote from their actual physical surrounding. Virtual environment systems could have a huge impact in education, entertainment, medicine,architecture, and training, but they are not widely used because of their expense and delicacy. Current interfaces to virtual environments such as treadmills, tracked head-mounted displays (HMDs), and joysticks suffer from being expensive, limited, and/or disorienting. Since HMD systems hold the promise of being readily available to the public within the next several years, constraints of the system need to be identified and addressed. In particular, a major drawback of HMD-based systems is the likely limited amount of space available for exploration. Thus, this thesis presents the development and evaluation of a system that allows people to explore a large virtual environment with an HMD when the size of the surrounding physical space is small. More specifically, this thesis focuses on exploring an HMD-based virtual environment by physically walking, i.e., bipedal locomotion. Bipedal locomotion is a highly effective method for learning the locations of things when exploring virtual environments, and seems to result in better spatial orientation than other locomotor interfaces such as joysticks. Bipedal locomotion within a virtual environment is easily accomplished as long as the physical space housing the tracking system and HMD are roughly the same size as the virtual environment. The issue becomes how to fit physical bipedal locomotion in a large virtual environment into a much smaller space while preserving a user's spatial orientation. This thesis thus develops engineering solutions that allow people to explore virtual environments that are much larger than the physical tracked space using their own locomotion. We explore several engineering solutions to designing this human-computer interface while using psychological experimentation to evaluate these techniques. The techniques presented in this thesis can be implemented and scale easily to any tracked HMD system.