Exploring the Front Touch Interface of Virtual Reality Head-Mounted Displays

Abstract

Virtual reality (VR) refers to three-dimensional realities implemented with stereo viewing goggles and reality gloves. The immersive experience that the VR technology provides entails a wide range of potential usages, and has attracted attentions from both the industrial and the academia for the last decades. Mobile VR headsets, VR head-mounted displays powered by smartphones, have recently been introduced, making VR more accessible and affordable than before. However, VR is not embraced by a broader scope of audience as much as the field expects. One of the reasons would be a lack of natural yet effective ways to interact with the VR world. This study introduces a new HMD-embedded interface, with which users can interact with the virtual world via a touchpad placed in front of the VR headset, namely front touch interface. This new interface has the potential to expand the design space of VR interactions, introducing new possible interaction methods. A prototype device was built on which a series of user studies were conducted to evaluate the fidelity of this new interface. Equations that map the coordinates of the 2D touchpad to that of the 3D virtual scene were made based on the data collected from a short pilot study. In addition, preliminary interviews were conducted to find how intuitive the interaction of touching the front space of headset is. And in the next study, the design space of the VR interactions, which was expanded by the introduction of the front touch interface, was explored. Then, two selection tests were conducted to find out how effective the front touch interface is with (1) menu interface and (2) keyboard. During this process, two new selection techniques, Two-Fingers and Drag-n-Tap, were proposed to explore an appropriate input method for the front touch interface. Each technique was devised to provide different types of benefits in terms of usability: Two-Fingers to help users make quicker selections, and Drag-n-Tap to achieve more accurate selections. Lastly, a short case study on VR media player was conducted, and how the front touch interface can provide with other alternative solutions was discussed. As a low-cost, light-weight, and low power-budget technology, a touch sensor makes a good medium for VR interaction. Also, the touch sensor could be embedded to the currently available VR headsets, requiring no extra devices. Such aspects of the front touch interface make it even more suitable for the mobile VR headsets, which attains highly portable and affordable characteristics. In future, further tests on unexplored design spaces and interaction gestures such as swiping and pinching will be conducted. This work is envisaged to shed light on a range of unexplored design possibilities.