DepthMove: Leveraging Head Motions in the Depth Dimension to Interact with Virtual Reality Head-Worn Displays

Head-based interactions are very handy for virtual reality (VR) head-worn display (HWD) systems. A useful head-based interaction technique could help users to interact with VR environments in a hands-free manner (i.e., without the need of a hand-held de-vice). Moreover, it can sometimes be seamlessly integrated with other input modalities to provide richer interaction possibilities. This paper explores the potential of a new approach that we call DepthMove to allow interactions that are based on head motions along the depth dimension. With DepthMove, a user can interact with a VR system proactively by moving the head perpendicular to the VR HWD forward or backward. We use two user studies to investigate, model, and optimize DepthMove by taking into con-sideration user performance, subjective response, and social ac-ceptability. The results allow us to determine the optimal and comfortable DepthMove range. We also distill recommendations that can be used to guide the design interfaces that use DepthMove for efficient and accurate interaction in VR HWD systems. A third study is conducted to demonstrate the usefulness of DepthMove relative to other techniques in four application scenarios.

1 Introduction

Head-based interactions are indispensable for virtual reality (VR) head-worn display (HWD) systems. When a user’s hands are occupied, or other ancillary devices (e.g., handheld controllers) are not available or not easily accessible, efficient head-based interaction techniques could be an alternative hands-free input approach for the user to interact with the VR system. Fig. la-b present an example scenario which calls for a feasible head-based interaction approach. A user is watching a movie in an HWD-based VR environment but suddenly gets interrupted by a message from an instant messaging app. When watching movies, the user does not usually carry a controller, and it might be inconvenient for her to take down the VR headset to find one. In this situation, a head-based approach to switch to the messaging interface and send a quick reply could become very practical.