Knock on Wood: Combining Redirected Touching and Physical Props for Tool-Based Interaction in Virtual Reality.

When physical props serve as proxies for virtual tools used to manipulate the virtual environment, it is challenging to provide appropriate haptic feedback. Redirected tool-mediated manipulation addresses this challenge by distorting the mapping between physical and virtual tools to provide a sensation of manipulating the virtual environment, when the physical tool comes into contact with another physical prop. For example, a virtual hammer's position can be offset to ensure that physical impacts accompany each strike of a virtual nail. We demonstrate the idea by showing that it can be used to create sensations of impact and resistance when driving a virtual nail into a surface, when tightening a virtual screw, and when sawing through a virtual plank. The results of a user study indicate that the proposed approach is perceived as more realistic than interaction with a single physical prop or controller and no notable detriments to precision were observed.