VR Bridges: Simulating Smooth Uneven Surfaces in VR

Virtual reality (VR) is limited in many ways and often is incomparable to real-world experience. Walkable smooth uneven surfaces are inherent to reality but extremely lacking in VR. At the same time, VR offers a lot of possibilities for manipulations. In this paper, we focus on human height and slant perception of the uneven surfaces with multi-sensory stimulation in VR. By employing viewport manipulations, haptic, and vibrotactile stimuli, we explore the possibility to simulate uneven surfaces different from the physical props used. Our results suggest that the use of a rounded prop helps to create a more convincing illusion of an uneven surface that is significantly higher than the physical one. The multi-sensory stimulation brings both height and slant estimations closer to the values suggested by the visual cues if there is no conflict with the haptic sensations. The use of a flat prop is less realistic and leads to massive height and slant underestimations as opposed to those suggested by visual cues. However, if the curved prop cannot be used, a flat surface might still be used to simulate small dents and bumps.