A Systematic Evaluation of Dragging Interaction Using Raycasting in Virtual Reality

Dragging is a fundamental interaction technique in human-computer interaction. Prior research on dragging has generally been concerned with 2D objects on 2D interactive surfaces, with limited attention to 3D interactive spaces. We performed three experiments to systematically investigate dragging using raycasting in virtual reality (VR), a representative 3D interactive environment. The first experiment examined dragging 2D targets on 2D surfaces placed in VR. The second experiment investigated dragging 3D targets positioned at identical depths in VR. Both experiments examined the effects of target depth, angular target amplitude, and angular target on dragging performance. The third experiment investigated dragging 3D targets with varying depths, focusing on the effects of target layout, target amplitude, and target width. Findings revealed the different impacts of the above factors on dragging interaction. We also proposed a new 3D Fitts' law model tailored for dragging using raycasting in VR, which fits well with our data. Finally, we discuss our results and provide design recommendations for dragging (i.e., translational positioning) tasks using raycasting under the tested experimental conditions in VR.