ImpactVest: Rendering Spatio-Temporal Multilevel Impact Force Feedback on Body in VR

ABSTRACT Rendering instant and intense impact feedback on users’ hands, limbs and head to enhance realism in virtual reality (VR) has been proposed in previous works, but impact on the body is still less discussed. With the body’s large surface area to utilize, numerous impact patterns can be rendered in versatile VR applications, e.g., being shot, blasted, punched or slashed on body in VR games. Herein we propose ImpactVest to render spatio-temporal multilevel impact force feedback on body. By independently controlling nine impactors in a 3 × 3 layout using elastic force, impact is generated at different levels, positions and time sequences for versatile spatial and temporal combinations. We conducted a just-noticeable difference (JND) study to understand users’ impact level distinguishability on the body. A time interval threshold study was then performed to ascertain what time interval thresholds between two impact stimuli should be used to distinguish from simultaneous impact, a continuous impact stroke and two discrete impact stimuli. Based on the results, we conducted a VR experience study to verify that impact feedback from ImpactVest enhances VR realism.