  Walking-in-place (WIP) is a locomotion technique that enables users to "walk
infinitely" through vast virtual environments using walking-like gestures
within a limited physical space. This paper investigates alternative
interaction schemes for WIP, addressing successively the control, input, and
output of WIP. First, we introduce a novel height-based control to increase
advanced speed. Second, we introduce a novel input system for WIP based on
elastic and passive strips. Third, we introduce the use of pseudo-haptic
feedback as a novel output for WIP meant to alter walking sensations. The
results of a series of user studies show that height and frequency based
control of WIP can facilitate higher virtual speed with greater efficacy and
ease than in frequency-based WIP. Second, using an upward elastic input system
can result in a stable virtual speed control, although excessively strong
elastic forces may impact the usability and user experience. Finally, using a
pseudo-haptic approach can improve the perceived realism of virtual slopes.
Taken together, our results suggest that, for future VR applications, there is
value in further research into the use of alternative interaction schemes for
walking-in-place.
