Background Within a virtual environment(VE)the control of locomotion(e.g.,self-travel)is critical for creating a realistic and functional experience.Usually the direction of locomotion,whileusing a head-mounted displa...Background Within a virtual environment(VE)the control of locomotion(e.g.,self-travel)is critical for creating a realistic and functional experience.Usually the direction of locomotion,whileusing a head-mounted display(HMD),is determined by the direction the head is pointing and the forwardor backward motion is controlled with a hand held controllers.However,hand held devices can be difficultto use while the eyes are covered with a HMD.Free hand gestures,that are tracked with a camera or ahand data glove,have an advantage of eliminating the need to look at the hand controller but the design ofhand or finger gestures for this purpose has not been well developed.Methods This study used a depth-sensing camera to track fingertip location(curling and straightening the fingers),which was converted toforward or backward self-travel in the VE.Fingertip position was converted to self-travel velocity using amapping function with three parameters:a region of zero velocity(dead zone)around the relaxed handposition,a linear relationship of fingertip position to velocity(slope orβ)beginning at the edge of the deadzone,and an exponential relationship rather than a linear one mapping fingertip position to velocity(exponent).Using a HMD,participants moved forward along a virtual road and stopped at a target on theroad by controlling self-travel velocity with finger flexion and extension.Each of the 3 mapping functionparameters was tested at 3 levels.Outcomes measured included usability ratings,fatigue,nausea,and timeto complete the tasks.Results Twenty subjects participated but five did not complete the study due tonausea.The size of the dead zone had little effect on performance or usability.Subjects preferred lower β values which were associated with better subjective ratings of control and reduced time to complete thetask,especially for large targets.Exponent values of 1.0 or greater were preferred and reduced the time tocomplete the task,especially for small targets.Conclusions Small finger movements can be used tocontrol velocity of self-travel in VE.The functions used for converting fingertip position to movementvelocity influence usability and performance.展开更多
文摘Background Within a virtual environment(VE)the control of locomotion(e.g.,self-travel)is critical for creating a realistic and functional experience.Usually the direction of locomotion,whileusing a head-mounted display(HMD),is determined by the direction the head is pointing and the forwardor backward motion is controlled with a hand held controllers.However,hand held devices can be difficultto use while the eyes are covered with a HMD.Free hand gestures,that are tracked with a camera or ahand data glove,have an advantage of eliminating the need to look at the hand controller but the design ofhand or finger gestures for this purpose has not been well developed.Methods This study used a depth-sensing camera to track fingertip location(curling and straightening the fingers),which was converted toforward or backward self-travel in the VE.Fingertip position was converted to self-travel velocity using amapping function with three parameters:a region of zero velocity(dead zone)around the relaxed handposition,a linear relationship of fingertip position to velocity(slope orβ)beginning at the edge of the deadzone,and an exponential relationship rather than a linear one mapping fingertip position to velocity(exponent).Using a HMD,participants moved forward along a virtual road and stopped at a target on theroad by controlling self-travel velocity with finger flexion and extension.Each of the 3 mapping functionparameters was tested at 3 levels.Outcomes measured included usability ratings,fatigue,nausea,and timeto complete the tasks.Results Twenty subjects participated but five did not complete the study due tonausea.The size of the dead zone had little effect on performance or usability.Subjects preferred lower β values which were associated with better subjective ratings of control and reduced time to complete thetask,especially for large targets.Exponent values of 1.0 or greater were preferred and reduced the time tocomplete the task,especially for small targets.Conclusions Small finger movements can be used tocontrol velocity of self-travel in VE.The functions used for converting fingertip position to movementvelocity influence usability and performance.
