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. This paper proposes to combine both techniques and reports 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.

中文翻译：

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结合动态被动触觉和触觉重定向以增强虚拟现实中的触觉反馈

为了提供身临其境的触觉体验，用于虚拟现实 (VR) 的基于代理的触觉反馈系统面临两个主要挑战：(1) 相似性和 (2) 托管。虽然要解决挑战 (1)，物理代理对象需要在触觉属性方面与其虚拟对象足够相似，但对于挑战 (2)，代理和虚拟对象需要充分共置以实现无缝交互。为了解决这些挑战，过去的研究引入了两种成功的技术：(a) 动态被动触觉反馈 (DPHF)，一种基于硬件的技术，利用可动道具在 VR 体验期间调整其物理状态，以及 (b) 触觉重定向，一种基于软件的技术，利用手重定向来弥合真实和虚拟对象之间的空间偏移。到目前为止，这两个概念都有，从来没有结合研究过。本文建议结合技术和报告，将感知和心理物理实验的结果结合起来，这些实验位于专注于虚拟重量分布感知的概念验证场景中。我们表明 VR 中的用户高估了重量变化，并且当 DPHF 和 HR 结合使用时，与仅使用重量转移道具或不明显的手重定向相比，可以呈现更大的变化。此外，我们发现 DPHF 和 HR 的组合可以让用户忽略代理和虚拟对应物的明显更大的空间错位。我们的调查首次展示了在实践中结合 DPHF 和 HR 的价值，验证了它们的结合可以比单独的单个技术更好地解决相似性和托管的挑战。