Tangiball: Foot-Enabled Embodied Tangible Interaction with a Ball in Virtual Reality

Interaction with tangible user interfaces (TUIs) in virtual reality (VR) is known to offer several benefits in terms of user experience. Incorporating identical-formed tangible objects for foot-enabled embodied interaction in VR is not a well-researched area. To address this gap, in this study, we explored foot-enabled embodied interaction in VR through a room-scale tangible soccer game (Tangiball). Users interacted with a physical ball with their feet in real time by seeing its virtual counterpart inside a VR head mounted display (HMD). Tangiball included a custom-built transparent physical ball, inside which motion trackers were secured using custom 3D-printed attachments. A between-subjects user study was performed with 40 participants, in which Tangiball was compared with the control condition of foot-enabled embodied interaction with a purely virtual ball. The results revealed that tangible interaction improved user performance and presence significantly, while no difference in terms of motion sickness was detected between the tangible and virtual versions. This paper discusses the development and evaluation of Tangiball along with implications of the user study results.