Comparing isometric and elastic surfboard interfaces for leaning-based travel in 3D virtual environments

Inspired by the Silver Surfer comics we developed a leaning-based surfboard interface which allows the user to fly in 3D virtual environments by shifting his/her center of mass on the board. The interface works in either an elastic tilt mode or an isometric balance mode offering different equilibrioceptive feedback to the user. Interested in how different levels of equilibrioceptive feedback influence the usability of this interface, a formal user study was conducted comparing the two modes in both separated and combined pitch and yaw travel tasks. Six of 30 subjects dropped out of the experiment because of cyber-sickness and were interviewed by the experimenter. Statistical analysis of data from the remaining subjects showed that although objectively there was no significant difference between the two modes regarding training effects and task performance, subjectively most subjects preferred the elastic tilt mode because of its intuitiveness, realism, fun, and sense of presence despite the greater fatigue and after effects (e.g., loss of balance) of using it. Based on the results we suggest a general preference of elastic devices and several design guidelines to future 3D VE travel interface designers.