Have A Seat: An Enhanced Reactive Alignment of a Single Target’s Position and Angle from the User’s Perspective in VR

Redirected Walking (RDW) techniques allow users to explore virtually infinite environments within constrained physical spaces. However, achieving precise alignment between physical and virtual targets remains a significant challenge. In particular, when both position and orientation of the targets need to align in order to get a proper haptic feedback like siting on a virtual chair. This paper introduces a revised version of the Reactive Alignment (REA) controller that simultaneously minimizes the Angular and Positional Distance Errors between a physical and a virtual target. The proposed method enhances spatial alignment and optimizes user navigation using a novel rotation gain control algorithm that takes angular misalignment into account. In addition, a new metric, $\Delta p$, is proposed to quantify the angular alignment, complementing the redefined Physical Distance Error (PDE) for positional accuracy. We implemented the algorithm on Oculus Quest head-mounted display and utilized the HMD's physical space tracking to locate the physical prop's location without the need of any external tracking. We also incorporated saccadic redirection by utilizing the HMD's eyetracking functionality to complement the revised REA approach. A user study demonstrates that the revised REA controller outperforms the original REA by reducing Physical Distance Error, angular error, and reset counts. It also enhanced user interaction with physical props by enabling users to successfully sit on a physical chair 60% of the time compared to 0% with the original REA when $\Delta p$ is zero.