Giant Finger: A Novel Visuo-Somatosensory Approach to Simulating Lower Body Movements in Virtual Reality

Surreal experience in virtual reality (VR) occurs when visual experience is accompanied by congruent somatosensation. Thus, VR contents that require physical actions are often bounded to our physical capabilities to maintain somatosensory consistency. Alternatively, users often choose less immersive but safer interfaces that offer a wider action variability. In either case, this situation compromises the potential for a hyper-realistic experience. To address this, we introduce “Giant Finger,” a concept that replicates human lower body movements through two enlarged virtual fingers in VR. Through a user study, we affirmed Giant Finger’s ownership using proprioceptive drift and questionnaire responses. We also compared Giant Finger’s capability to perform a variety of tasks with existing methods. Despite its minimalistic approach, Giant Finger demonstrated a high level of efficacy in supporting lower body movements, with ownership and presence comparable to those of the body-leaning method with whole-body motion. Giant Finger can replace the sensations of real legs or support locomotion in confined spaces by providing proprioceptive illusions to the virtual lower body. The applications showcased in this paper suggest that Giant Finger can enable new forms of movement with high action variability and immersion in various fields such as gaming, industry, and accessibility.