A hybrid 2D–3D tangible interface combining a smartphone and controller for virtual reality

Virtual reality (VR) controllers are widely used for 3D virtual object selection and manipulation in immersive virtual worlds, while touchscreen-based devices like smartphones or tablets provide precise 2D tangible input. However, VR controllers and touchscreens are used separately in most cases. This research physically integrates a VR controller and a smartphone to create a hybrid 2D–3D tangible interface for VR interactions, combining the strength of both devices. The hybrid interface inherits physical buttons, 3D tracking, and spatial input from the VR controller while having tangible feedback, 2D precise input, and content display from the smartphone’s touchscreen. We review the capabilities of VR controllers and smartphones to summarize design principles and then present a design space with nine typical interaction paradigms for the hybrid interface. We developed an interactive prototype and three application modes to demonstrate the combination of individual interaction paradigms in various VR scenarios. We conducted a formal user study through a guided walkthrough to evaluate the usability of the hybrid interface. The results were positive, with participants reporting above-average usability and rating the system as excellent on four out of six user experience questionnaire scales. We also described two use cases to demonstrate the potential of the hybrid interface.