Combining Dynamic Passive Haptics & Haptic Retargeting in VR
Shifting & Warping - Enhancing Proxy-Based Haptic Feedback for VR
To provide immersive haptic experiences, proxy-based haptic feedback systems for virtual reality (VR) face two central challenges: (1) similarity, and (2) colocation. While to solve challenge (1), physical proxy objects need to be sufficiently similar to their virtual counterparts in terms of haptic properties, for challenge (2), proxies and virtual counterparts need to be sufficiently colocated to allow for seamless interactions. To solve these challenges, past research introduced, among others, two successful techniques: (a) Dynamic Passive Haptic Feedback (DPHF), a hardware-based technique that leverages actuated props adapting their physical state during the VR experience, and (b) Haptic Retargeting, a software-based technique leveraging hand redirection to bridge spatial offsets between real and virtual objects.
Both concepts have, up to now, not ever been studied in combination. We propose to combine both techniques and report on the results of a perceptual and a psychophysical experiment situated in a proof-of-concept scenario focused on the perception of virtual weight distribution. We show that users in VR overestimate weight shifts and that, when DPHF and HR are combined, significantly greater shifts can be rendered, compared to using only a weight-shifting prop or unnoticeable hand redirection. Moreover, we find the combination of DPHF and HR to let significantly larger spatial dislocations of proxy and virtual counterpart go unnoticed by users.
Our investigation is the first to show the value of combining DPHF and HR in practice, validating that their combination can better solve the challenges of similarity and colocation than the individual techniques can do alone.
We first presented the idea of combining a weight-shifting proxy with unnoticeable hand redirection in a thought experiment published as a poster at UIST 2020.
To validate our concept and to prove its practical feasibility, we now implemented the combined technique and report on two perceptual user experiments that highlight the benefits of combining a dynamic prop with haptic retargeting in our IEEE TVCG paper published and presented at IEEE VR 2021.
We compared 4 different techniques to haptically render the weight distribution inside a virtual stick ...
... in two perceptual VR experiments.