Impact of Spatial Reference Frames on Human Performance in Virtual Reality User Interfaces

The design of virtual reality user interfaces (VRUI) is still an open field of research and development. One category of VRUI is the 3D floating menus that can be manipulated by users in free space. These menus can contain various controls such as buttons, sliders, and text. This article presents an experimental study that aims at testing the impact of five spatial reference frames on human performance with VRUI. Fifteen subjects participated in the study. Wearing a head-mounted display (HMD) and tracking hardware, they were asked to move a slider on a floating menu in a 3D virtual space. The menus were completely virtual such that no physical surface was providing haptic feedback to the user. Main results show that the reference frame has a determinant impact on task execution time, positional accuracy and user preference. We also found a link between the number of degrees of freedom shared between these reference frame and user performance. Results also show that user preference can greatly differ from experimental results obtained by measuring task completion times and positional accuracy.