2021/22
Project Context Academic Paper and Master’s Thesis
Roles User researcher, Unity development
Challenge Some users of virtual reality (VR) can experience motion sickness. My task was to study methods that could potentially reduce motion sickness in VR while walking on the Virtualizer, an omnidirectional treadmill.
Result Paper published in the journal IEEE Transactions on Human-Machine Systems. Furthermore, a Master’s thesis discussing 14 potential motion sickness reducing methods and a user study testing 3 of those.
Details
In the last decade, VR has gone through incredible technological developments making it much more comfortable to use these days. Nevertheless, some users might still experience symptoms related to motion sickness, like nausea, headaches and/or dizziness. This so-called cybersickness can push new users away from VR. Thus, it is essential to extend the knowledge on both the causes and potential solutions to cybersickness. The omnidirectional treadmill of Cyberith, the Virtualizer ELITE 2, might remove some of the causes of sickness. Nevertheless, it does not fully eliminate cybersickness. For my master’s thesis, I sought to find effective methods for reducing cybersickness specifically in the context of the Virtualizer.
I reviewed academic literature to study what was already known about the causes of motion sickness in VR and potential solutions. From this, I gathered a list of 14 potential sickness-reducing methods. To test them all was beyond the scope of my project. So, I chose 3 methods that were the most relevant to my context. It had to be methods that were not already covered extensively in research and also work with the Virtualizer. The chosen methods were movement speed, movement smoothing and a virtual body representation (avatar).
For the user study, I built a maze in Unity for the 39 participants to walk through. I collected data through questionnaires, from comments of the participants during and after the VR session, and motion data from trackers. From the methods, only movement speed significantly affected the perceived sickness symptoms. When the speed was lower, participants generally reported lower levels of sickness. Conversely, participants often preferred higher speeds. This exemplifies the need for finding the balance between not getting sick, but also not feeling sluggish. The study also helped identifying a hidden software issue that increased motion sickness. After identification, Cyberith was able to quickly eliminate the issue with a software update.
After the thesis was finished, I wrote a peer-reviewed article with Dr. Luca Turchet for the journal IEEE Transactions on Human-Machine Systems. You can find the article at the bottom of this page. As a result of my experience with cybersickness, I was asked to give a guest lecture on VR locomotion and cybersickness at the University of Twente for the course Experience Design for Interaction in May 2023.
