Horizontal Plane Haptic Redirection: Realizing Haptic Feedback for the Virtual Inclined Plane in VR.

Some interactions in virtual environments need to be operated on inclined planes. If a real inclined plane can be found in the real environment that corresponds exactly to the angle of the virtual inclined plane to provide haptic feedback, the user's immersion can be enhanced. However, it is not easy to find such a real inclined plane in the real environment. We proposed a horizontal plane haptic redirection scheme, where users interacting with virtual inclined planes in virtual environments can obtain haptic feelings by using real horizontal planes that are easily available in the real world for redirection mapping. We also designed an integrated solution to locate the real horizontal plane and for haptic redirection based on the Vive Pro headset. Then we measured the angle and size thresholds for horizontal plane haptic redirection as 20° and 88%, respectively, through a user study. Through experiments, we also found that when the degree of redirection exceeded the threshold, the user's operation efficiency would be significantly reduced. In addition, we compared the horizontal plane haptic redirection scheme with the scheme without redirection and the scheme without haptic feedback to demonstrate the validity and necessity of the redirection scheme proposed in this paper.