Effects of physical walking on eyes-engaged target selection with ray-casting pointing in virtual reality

Target selection in virtual reality (VR) is usually carried out with the need of visual attention. While target selection in VR has been extensively investigated in non-walking activities (e.g., sitting or standing), there have been few studies about eyes-engaged target selection during walking in virtual environments. Therefore, we conducted a comprehensive study to explore the effects of physical walking (as an independent variable with low, medium and high speeds) on eyes-engaged selection tasks with targets (three target sizes and three target depths) in two experiments: targets fixed in the virtual environment (Experiment One) and targets fixed to the virtual body (Experiment Two), respectively. Results showed that for Experiment One, the low walking speed led to the significantly longest task completion time, while the medium and high speeds had similar task completion time. For Experiment Two, higher walking speed led to longer task completion time. In both tasks, error rate significantly increased as walking speed increased. The effects of walking speed also varied across target size and target depth. We conclude our study with a set of design implications for target selection tasks when walking in VR environments.