MVPie Menu: A Multimodal Voice- enhanced Pie Menu for VR System Control

System control in immersive virtual environments play a critical role in determining the user experience of interacting with 3D User Interfaces (UI). While a lot of the 2D desktop UI elements can be adapted to Virtual Reality (VR) systems, they may not be the most suitable for complex tasks. We created a multimodal interaction technique combining a pie menu with voice command support to improve the efficiency of completing complex tasks. A pilot study was conducted to evaluate this technique against a basic hierarchical pie menu. Our result from the study shows that users use voice commands more often for tasks that require users to navigate nested layers on the menu. However, users prefer to use the raycasting technique for easy tasks and found the voice control technique requiring higher workload.