Stacked Retargeting: Combining Redirected Walking and Hand Redirection to Expand Haptic Retargeting's Coverage

We present Stacked Retargeting—combining haptic retargeting and redirected walking—to maximise the use of passive proxy objects for VR haptics. Haptic retargeting work to date has considered stationary reaching and grasping interactions, and this inherently limits a proxy object's scope. We consider exactly where this reaching and grasping occurs from, to increase the potential of each proxy. We present (a) a staged approach to implementing Stacked Retargeting, (b) five redirected walking approaches that enable users to arrive anywhere at the site of interaction, and (c) a usability magnitude estimation evaluation of these techniques. We demonstrate how Stacked Retargeting can meaningfully increase the practical use of proxy objects for VR haptics without degrading the user experience.