Tackling VR sickness: A novel benchmark system for assessing contributing factors and mitigation strategies

VR sickness, a form of motion sickness induced by Virtual Reality (VR) experiences, remains a significant challenge in the widespread adoption and usability of VR technologies. Despite its impact, the absence of a standardized benchmark system to assess VR sickness reduction methods hinders progress in understanding and effectively countering contributing factors. This paper proposes a novel benchmark system, utilizing a pioneering methodological approach, to serve as a common platform for evaluating potential factors contributing to VR sickness and testing mitigation techniques. Leveraging established VR sickness theories and a systematic design approach, our proposed benchmark, implemented in Unity, integrates a VR scenario with two distinct VR environments — small and large — to systematically and controllably induce VR sickness across participants. Our approach employs a real-time self-rated percentage scale for VR sickness, complementing traditional measurements such as the Simulator Sickness Questionnaire (SSQ), and offering insights into the immediate impacts of VR exposure, onset and recovery of symptoms, and the effectiveness of mitigation techniques. To demonstrate the usability and validity of our benchmark system, we conducted two studies, in which participants continuously rated their VR sickness, allowing us to track the progression of symptoms during VR exposure, until reaching a moderate threshold (50\% on the self-rated scale). Results demonstrated the system's capability to (1) quickly and reliably induce VR sickness in both environments, followed by a rapid decline post-stimulus, together enabling within-subject studies that offer reduced cost, time, and effort, as well as increased statistical power, and (2) integrate and test four established VR sickness mitigation methods — static and dynamic field of view reduction, blur, and virtual nose — demonstrating their effectiveness in reducing symptoms in the benchmark and marking the first time these techniques have been directly compared within a standardized setting. Our proposed benchmark not only facilitates efficient evaluation and comparison of VR sickness mitigation techniques, but also enables broader, more comparative research into different technical, setup, and participant variables influencing VR sickness and overall user experience. This will ultimately pave the way for building a comprehensive database to identify the most effective strategies for specific VR applications.