VR technology is more affordable than ever, with increasing use in consumer and enterprise applications. However, engineers have not yet achieved a sense of full immersion in a virtual world; among the greatest challenges is conveying the sensation of movement, such as walking.

Engineers from the two Japanese universities collaborated to develop a custom platform to simulate walking in a virtual environment.

“Walking is a fundamental activity for humans in everyday life. Therefore, it is very worthwhile to provide a high-quality walking experience in a VR space,” said Professor Yusuke Matsuda of Toyohashi University, co-author of the Frontiers in Virtual Reality paper describing the platform.

“We believe that the general public is very likely to be interested in this study that combines walking and VR experiences, which have seen rapid growth in demand as a result of Covid-19.”

Matsuda and his colleagues explored whether a full-body or hands-and-feet-only walking avatar seen through first-person and third-person perspectives can convey the sensation of walking in a virtual environment through optic flows (the apparent patterns of movement of objects moving relative to a viewer) and rhythmic foot vibrations.

When the participant moves their avatar, the platform synchronises with these movements to create the sensation that the avatar is their own body. For instance, their field of vision in the virtual world is linked to their head movements.

40 participants were split into first-person and third-person perspective experiments. Each participant sat on a stool and their feet were connected to four vibro-transducers (made from springs and wood plates). When the avatar’s foot strikes the ground, the foot vibrations were applied rhythmically to the heel and forefoot of the foot. The participants wore headphones emitting white noise to eliminate the sound of the system.

In the virtual world, the participants 'walked' down a corridor with a textured floor and mirrors hanging on its wooden walls. The inclusion of reflections in these mirrors made it possible for the participant to see their avatar, improving their perception of walking while sitting motionlessly.

“Our study showed that a walking avatar in a first-person perspective enhanced the sensation of walking,” said Matsuda. “The effects were observed not only when the full-body avatar was used, but also when only the hands and feet were presented without the hands-and-feet-only avatar.”

The participants felt no sensation of walking when they viewed the avatar from a third-person perspective; from this perspective, both avatars impaired the “self-motion sensation and telepresence” and the foot vibrations made no difference to this lack of immersion.

Matsuda and his colleagues hope to develop the platform further such that it can be scaled and potentially commercialised for use in gaming. It could also have applications for people with mobility issues; although VR walking systems have been developed, most of these require physical leg movements and tend to be too large and heavy for use at home.

“One of the most important features of the walking device we proposed is that it gives tactile and visual stimuli to seated users. Besides, for those without mobility issues, the proposed method is simply less fatiguing than moving the legs by oneself. Therefore, we will be able to easily experience virtual walking for a relatively long time,” said Matsuda.