Abstract
Gesture-based systems allow users to interact with a virtual reality application in a natural way. Visual feedback for the gesture-based interaction technique has an impact on the performance and the hand instability making the manipulation of the object less precise. This paper investigated two new interaction techniques in a virtual environment. It describes the influence of natural and non-natural virtual feedback in the selection process using the GITDVR-G interaction technique, which consists of a grasping visual feedback. The GITDVR-G was evaluated in a virtual knee surgery training system. The results showed that it was effective in terms of the task completion time, and that the participants preferred the natural grasping visual feedback. Besides that, the precise manipulation in a newly-designed interaction technique (Precise GITDVR-G) was evaluated. The Precise GITDVR-G includes a normal manipulation mode and a precise manipulation mode that can be triggered by hand gestures. During the precise manipulation mode, an inset view will appear and move with the selected object to provide a better view to users, while the movements of the virtual hand are scaled down to improve the precision. Four different configurations of the precise manipulation technique were evaluated, and the results showed that the unimanual control method with an inset view performed better in terms of the task performance time and the subjective feedback. The finding suggested that the realistic virtual grasping visual feedback can be applied in a virtual hand interaction technique, and that the inset view feature is helpful in the precise manipulation.