Blurry touch finger: Touch-based interaction for mobile virtual reality with clip-on lenses

In this paper, we propose and explore a touch screen based interaction technique, called the “Blurry Touch Finger” for EasyVR, a mobile VR platform with non-isolating flip-on glasses that allows the fingers accessible to the screen. We demonstrate that, with the proposed technique, the user is able to accurately select virtual objects, seen under the lenses, directly with the fingers even though they are blurred and physically block the target object. This is possible owing to the binocular rivalry that renders the fingertips semi-transparent. We carried out a first stage basic evaluation assessing the object selection performance and general usability of Blurry Touch Finger. The study has revealed that, for objects with the screen space sizes greater than about 0.5 cm, the selection performance and usability of the Blurry Touch Finger, as applied in the EasyVR configuration, was comparable to or higher than those with both the conventional head-directed and hand/controller based ray-casting selection methods. However, for smaller sized objects, much below the size of the fingertip, the touch based selection was both less performing and usable due to the usual fat finger problem and difficulty in stereoscopic focus.