Research On The Differences In Operation Characteristics Between Eye Control And Head Control For Selecting Moving Targets In Virtual Reality

With the development of wireless portable virtual reality(VR)headsets,portable interaction methods have become crucial.Eye tracking and head tracking are two potential and similar important interaction methods,and it is important to clearly define their respective usage scenarios.Selecting static and moving targets is the most common interaction scenario in VR.Previous studies have mainly focused on the differences in operational characteristics between eye tracking and head tracking in the selection of static targets,with the results showing that head tracking is more efficient than eye tracking.However,few researchers have explored the operational characteristics differences between eye tracking and head tracking in selecting moving targets.Eye tracking has the characteristic of stable and smooth tracking of moving targets;therefore,it is speculated that compared to selecting static targets,the operational efficiency difference between eye tracking and head tracking in selecting moving targets may decrease or even favor eye tracking.Therefore,the purpose of this study is to systematically investigate the operational characteristics differences between eye tracking and head tracking in selecting moving targets in receding and approaching movement scenario.Fifty college students(24 males,26 females)participated in the experiment.They wore virtual reality headsets and used eye tracking and head tracking to quickly and accurately place a cursor ball into a larger translucent target ball that was moving along a curve away from the cursor(Experiment 1,receding movement)or towards the cursor(Experiment 2,approaching movement).The experiment varied the target’s movement speed(static,5°/s,10°/s,15°/s),the initial distance between the cursor and the target(20°,40°,60°),and the size difference between the cursor and the target(target tolerance: 4°,8°,12°).The experimental results showed that in selecting static targets,the operational time of head tracking was less than that of eye tracking,supporting the previous research results.However,for selecting moving targets in receding and approaching movement scenario,the operational efficiency differences between eye tracking and head tracking were different.In selecting moving targets in receding movement scenario,the operational time of eye tracking was less than that of head tracking,supporting our hypothesis,and the difference in operational time between the two was the greatest when the target speed was 5°/s.As the target speed further increased,the time difference between the two gradually decreased.In addition,the operational time difference between the two was also affected by the target tolerance.Conversely,in selecting moving targets in approaching movement scenario,eye tracking did not show operational efficiency advantages,and the operational time of head tracking was significantly lower than that of eye tracking,and the operational time advantage of head tracking increased with the increase in target speed.However,the relative time advantages of head tracking and eye tracking were not significantly affected by the movement amplitude and target tolerance.We further divided the movement process of eye tracking and head tracking into the ballistic phase(from the starting point of the cursor to the first time it is tangent to the target)and the corrective phase(from the first time the cursor is tangent to the target to completely placing it inside the target ball).The results showed that in receding and approaching movement scenario,the operational time differences between eye tracking and head tracking showed similar changing patterns in both phases.This study demonstrated that there are operational time differences in the characteristics of eye tracking and head tracking in selecting moving targets in receding and approaching movement scenario,further enriching the application scenarios of eye tracking and head tracking,and providing important references for the interaction design and efficient interaction method selection of eye tracking and head tracking in VR scenarios.