Mapping Various Large Virtual Spaces to Small Real Spaces: A Novel Redirected Walking Method for Immersive VR Navigation

Real-walking techniques such as redirected walking can provide users with a highly immersive presence in virtual environments. However, different space sizes or boundary shapes of virtual and real spaces limit the performance of real-walking techniques. This article proposes a novel redirected walking method supporting users continuously navigating in various large virtual spaces by real-walking in small real spaces. Herein, we present a Voronoi-based method to generate paths called the skeleton graph consisting of navigable paths and way-points. To map the skeleton graph of the virtual space to the real space, we propose a static graph mapping method adopting relocation and curvature adjustment. Additionally, a global optimization with boundary constraints is applied to minimize the total curvature of all paths, resulting in the complete convergence of the mapped paths in real space. By applying both virtual and mapped skeleton graphs in the roaming, our method provides users with a continuous walking experience without any interruptions. The experimental results show that unlike the existing methods that are only effective for specific virtual spaces, our method enables effective real-walking roaming in various large virtual spaces, that have polygon-shaped floor plans, and successfully reduces the number of collisions and perceptual distortion in the virtual scenes.