Publications
illumotion: An Optical-illusion-based VR Locomotion Technique for Long-Distance 3D Movement
Sin, Zackary PT, Jia, Ye, Li, Richard Chen, Leong, Hong Va, Li, Qing, Ng, Peter HF
2024 IEEE Conference Virtual Reality and 3D User Interfaces (VR) (2024)
Locomotion has a marked impact on user experience in VR, but currently, common to-go techniques such as steering and teleportation have their limitations. Particularly, steering is prone to cybersickness, while teleportation trades presence for mitigating cybersickness. Inspired by how we manipulate a picture on a mobile phone, we propose illumotion, an optical-illusion-based method that, we believe, can provide an alternative to these two typical techniques. Instead of zooming in a picture by pinching two fingers, we can move forward by "zooming" toward part of the 3D virtual scene with pinched hands. Not only is the proposed technique easy to use, it also seems to minimize cybersickness to some degree. illumotion relies on the manipulation of optics; as such, it requires solving motion parameters in screen space and a model of how we perceive depth. To evaluate it, a comprehensive user study with 66 users was conducted. Results show that, compared with either teleportation, steering or both, illumotion has better performance, presence, usability, user experience and cybersickness alleviation. We believe the result is a clear indication that our novel opticallydriven method is a promising candidate for generalized locomotion.
Traceable teleportation: Improving spatial learning in virtual locomotion
Ye Jia, Zackary P. T. Sin, Chen Li, Peter H. F. Ng, Xiao Huang, George Baciu, Jiannong Cao, Qing Li
International Journal of Human-Computer Studies (2025)
In virtual reality, point-and-teleport (P&T) is a locomotion technique that is popular for its user-friendliness, lowering workload and mitigating cybersickness. However, most P&T schemes use instantaneous transitions, which has been known to hinder spatial learning. While replacing instantaneous transitions with animated interpolations can address this issue, they may inadvertently induce cybersickness. To counter these deficiencies, we propose Traceable Teleportation (TTP), an enhanced locomotion technique grounded in a theoretical framework that was designed to improve spatial learning. TTP incorporates two novel features: an Undo-Redo mechanism that facilitates rapid back-and-forth movements, and a Visualized Path that offers additional visual cues. We have conducted a user study via a set of spatial learning tests within a virtual labyrinth to assess the effect of these enhancements on the P&T technique. Our findings indicate that the TTP Undo-Redo design generally facilitates the learning of orientational spatial knowledge without incurring additional cybersickness or diminishing sense of presence.
A scoping review on the role of virtual walking intervention in enhancing wellness
Yushen Dai, Jiaying Li, Yan Li, Frances Kam Yuet Wong, Mengqi Li, Chen Li, Ye Jia, Yueying Wang, Janelle Yorke
npj Digital Medicine (2025)
Virtual walking has the potential to be an adjunct to traditional physical therapy. This scoping review aims to synthesize evidence on the characteristics, effectiveness, feasibility, and neurological mechanism of virtual walking interventions on health-related outcomes. Articles in English were retrieved from twelve databases (January 2014–October 2024). Thirteen interventional studies were included, focusing on three types of virtual walking: passive observing moving (71.4%), arm swing locomotion (21.5%), and foot tracking locomotion (7.1%). Most studies (84.6%) involved individuals with spinal cord injuries, while the remaining studies focused on lower back pain (7.7%) and lower limb pain (7.7%). Over 70% of studies lasted 11–20 min, 1–5 weekly sessions for 10–14 days. Statistically significant findings included pain reduction (84.6%), improved physical function (mobility and muscle strength), and reduced depression. Mild adverse effects (fatigue and dizziness) were transient. Neurological evidence indicates somatosensory cortex activation during virtual walking, possibly linked to neuropathic pain.