Head movements; Mobile device; Touch interaction; Virtual large displays; VR
Virtual Reality (VR) headsets can open opportunities for users to accomplish complex tasks on large virtual displays using compact and portable devices. However, interacting with such large virtual displays using existing interaction techniques might cause fatigue, especially for precise manipulation tasks, due to the lack of physical surfaces. To deal with this issue, we explored the design of VXSlate, an interaction technique that uses a large virtual display as an expansion of a tablet. We combined a user's head movements as tracked by the VR headset, and touch interaction on the tablet. Using VXSlate, a user head movements positions a virtual representation of the tablet together with the user's hand, on the large virtual display. This allows the user to perform fine-tuned multi-touch content manipulations. In a user study with seventeen participants, we investigated the effects of VXSlate on users in problem-solving tasks involving content manipulations at different levels of difficulty, such as translation, rotation, scaling, and sketching. As a baseline for comparison, off-the-shelf touch-controller interactions were used. Overall, VXSlate allowed participants to complete the task with completion times and accuracy that are comparable to touch-controller interactions. After an interval of use, VXSlate significantly reduced users' time to perform scaling tasks in content manipulations, as well as reducing perceived effort. We reflected on the advantages and disadvantages of VXSlate in content manipulation on large virtual displays and explored further applications within the VXSlate design space.