David Waller - US grants

In the last two decades there has been a great deal of interest among scholars, business leaders, and the general public in real-time interactive 3D computer graphics for inmersive virtual environments, in which the user wears a head-mounted display and his/her movements are tracked by sensors. This technology offers great promise as a natural means of interacting with computer-generated environments. To date, however, immersive virtual environments have had difficulty accommodating multiple users, due both to a lack of available space and because of the inherent risk of collision when multiple users, each effectively blindfolded by a head mounted display, walk in the same area. The PI and his team have created a unique system called the HIVE (for Huge Immersive Virtual Environment) on the campus of Miami University in Oxford, Ohio. This is the world's largest indoor immersive virtual environment by a factor of four, offering precise, wireless, untethered tracking of users in a 1000 m2 gymnasium. Additionally, the team has developed effective software algorithms that imperceptibly steer users towards the HIVE's center and away from its walls, a capability that can be leveraged to steer multiple users around each other to prevent collisions. Despite these advances, there are three ways in which the HIVE's capabilities need to be further enhanced to support multiple users:

1. The HIVE currently possesses only two wearable rendering systems; several more are needed to pursue multi-user applications.

2. The HIVE's optical position tracking system was designed for much smaller tracking volumes, and needs to be upgraded to support robust multi-user simulations.

3. Substantial effort will be required to enhance the HIVE's existing software base to include functionality such as collision prediction algorithms that can support multiple users.

This is funding to provide these enhancements to the HIVE's existing hardware and software infrastructure, which will have an immediate effect on its utility for research, education, data visualization, and training.

Broader Impacts: The enhanced infrastructure will enable research in computer science that: (a) develops, evaluates, and compares 3D user interfaces; (b) develops algorithms for collision detection and multi-user redirected walking; (c) explores the use of inertial sensors for position tracking in portable virtual environments; and (d) develops tools for collaborative computing environments. Additional behavioral research enabled by this funding will aim to improve our understanding of how humans learn and remember large spaces, and of the social dynamics of users who cohabit a computer simulation. The improved infrastructure will also have a dramatic impact on educators who use the HIVE, by enabling: (a) several students and an instructor to be simultaneously involved in educational simulations; (b) new opportunities for hands-on student projects, particularly those that involve partnerships with industry clients to develop real-world products, services, and interactive media; and (c) the digital preservation and demonstration of culturally important spaces.

In recent years immersive real-time interactive 3D computer environments (virtual reality or VR) have become an invaluable tool for research and development, training, healthcare, commerce, communication, and education, as well as a medium for entertainment. Yet, in general, the use of current VR systems requires travel to specialized facilities in which a sophisticated infrastructure has been pre-installed at great expense. Furthermore, although fully immersive systems that allow teams of users to concurrently explore a simulated environment by walking, turning, and looking around in a natural manner are particularly useful because they provide increased realism through multisensory stimulation, current VR facilities often support only one user at a time who is constrained to explore the virtual world by means of an artificial interface or a movement metaphor that is arbitrary and awkward (e.g., treadmills or walking in place). For most people, the benefits of VR are thus relatively inaccessible and fall quite short of their promise. In this collaborative effort between Miami University and the Naval Postgraduate School, the PIs will conduct research whose goal is to develop an innovative immersive VR system that is completely portable, that will allow multiple users to be immersed simultaneously, and that can be used in any large indoor or outdoor area such as a gymnasium or parking lot. Users will be able to walk naturally for miles in a virtual world without ever becoming aware of the physical limits of the tracking space or the locations of other users. A system capable of immersing a single user will cost an order of magnitude less than current systems. To these ends the PIs will exploit two emerging techniques: redirected walking, an algorithm that imperceptibly steers users away from obstacles such as walls and which the PIs have previously shown can, given a physical area of sufficient size, enable users to navigate through a virtual world of unlimited size in a natural manner without encountering real-world boundaries and obstacles; and self contained inertial position tracking, which prior research has shown can be used to accurately monitor and track the position and orientation of the user's viewpoint in space without the need for pre-installed permanent infrastructure. In addition, the PIs will integrate into the new VR technology ultrasonic mapping and positioning, a technique commonly used in robotics to provide estimates of absolute position.

Broader Impacts: By creating VR systems that are portable and relatively inexpensive, this research will take significant steps toward making VR technology available to a much broader range of people than has heretofore been possible, providing first-hand exposure to cutting-edge concepts and models in science and technology to any population that educators or researchers chose. In particular, the work will enable students at any grade level to experience computer simulations and models by walking within them, instead of by reading about them or by viewing them as an outside observer. The synthesis of redirected walking and self-contained inertial position tracking will offer rich research potential in the computer and behavioral sciences. Implementing relative position tracking through inertial sensors and periodic position fixes instantiates a biologically plausible model of navigation and can parallel research on how humans and other animals find their way through environments.