The Effect of Semi-Transparent and Interpenetrable Hands on Object Manipulation in Virtual Reality

Manipulating objects with the hand is a common task in Virtual Reality (VR). However, some issues can occur during these manipulations. Occlusion is one issue that happens when the virtual hand covers an object, and therefore the perception of that object is hindered. Semi-transparent hands could solve this problem. Another issue is the difficulty of delicate hand object manipulation. By using interpenetrable hands, turning off the physics of the hands, this difficulty might decrease. Still, there is a lack of research into how significant the impact is while using these methods. In this paper, with the designs of semi-transparent hands and interpenetrable hands, we present the results of our conducted user study focusing on the effect of semi-transparent and interpenetrable hands on hand object manipulation tasks in virtual reality. The user study includes a VR environment where participants are asked to perform tasks. These tasks are recorded in objective results of accuracy and speed. Afterwards, they fill out a questionnaire about their opinion on the difficulty while using the different methods in which the subjective findings are recorded. Additionally, we improved the semi-transparent hands by adding a feature that smoothly transitions the hand from opaque to semi-transparent. As an input device, we used the Leap Motion Controller (LMC) for this user study. However, any hand tracking sensor that tracks hands from the VR headset's point of view could be used. Semi-transparent and interpenetrable hands have shown significant improvement for precise manipulation, which was verified by user feedback from the questionnaire and the data from the tasks.