Spherical Layout with Proximity-Based Multimodal Feedback for Eyes-Free Target Acquisition in Virtual Reality

摘要

Eyes-free interaction can reduce the frequency of headset rotation and speed up the performance via proprioception in Virtual Environments (VEs). However, proprioception cues make it difficult and uncomfortable to select the targets located at further distance. In VEs, proximity-based multimodal feedback has been suggested to provide additional spatial-temporal relation for 3D selection. Thus, in this work, we mainly study how such multimodal feedback can assist eyes-free target acquisition in a spherical layout, where the target size is proportional to the horizontally egocentric distance. This means that targets located at further distance become bigger allowing users to acquire easily. We conducted an experiment to compare the performance of eyes-free target acquisition under four feedback conditions (none, auditory, haptic, bimodal) in the spherical or cylinder layout. Results showed that three types of feedback significantly reduce acquisition errors. In contrast, no significant difference was found between spherical and cylinder layouts on time performance and acquisition accuracy, however, most participants prefer the spherical layout for comfort. The results suggest that the improvement of eyes-free target acquisition can be obtained through proximity-based multimodal feedback in VEs.