We present AirRacket, perceptual modeling and design of ungrounded, directional force feedback for virtual racket sports. Using compressed air propulsion jets to provide directional impact forces, we iteratively designed for three popular sports that span a wide range of force magnitudes: ping-pong, badminton, and tennis. To address the limited force magnitude of ungrounded force feedback technologies, we conducted a perception study which discovered the novel illusion that users perceive larger impact force magnitudes with longer impact duration, by an average factor of 2.57x. Through a series of formative, perceptual, and user experience studies with a combined total of 72 unique participants, we explored several perceptual designs using force magnitude scaling and duration scaling methods to expand the dynamic range of perceived force magnitude. Our user experience evaluation showed that perceptual designs can significantly improve realism and preference vs. physics-based designs for ungrounded force feedback systems.
Virtual reality (VR) has increasingly been used in many areas, and the need to deliver notifications in VR is also expected to increase accordingly. However, untimely interruptions could largely impact the experience in VR. Identifying opportune times to deliver notifications to users allows for notifications to be scheduled in a way that minimizes disruption. We conducted a study to investigate the use of sensor data available on an off-the-shelf VR device and additional contextual information, including current activity and engagement of users, to predict opportune moments for sending notifications using deep learning models. Our analysis shows that using mainly sensor features could achieve 72% recall, 71% precision and 0.86 area under receiver operating characteristic (AUROC); performance can be further improved to 81% recall, 82% precision, and 0.93 AUROC if information about activity and summarized user engagement is included.
Virtual Reality (VR) bicycle simulations aim to recreate the feeling of riding a bicycle and are commonly used in many application areas. However, current solutions still create mismatches between the visuals and physical movement, which causes VR sickness and diminishes the cycling experience. To reduce VR sickness in bicycle simulators, we conducted two controlled lab experiments addressing two main causes of VR sickness: (1) steering methods and (2) cycling trajectory. In the first experiment (N = 18) we compared handlebar, HMD, and upper-body steering methods. In the second experiment (N = 24) we explored three types of movement in VR (1D, 2D, and 3D trajectories) and three countermeasures (airflow, vibration, and dynamic Field-of-View) to reduce VR sickness. We found that handlebar steering leads to the lowest VR sickness without decreasing cycling performance and airflow suggests to be the most promising method to reduce VR sickness for all three types of trajectories.
Dancing is a universal human activity, and also a domain of enduring significance in Human-Computer Interaction (HCI) research. However, there has been limited investigation into how computing supports the experiences of recreational dancers. Concurrently, a diverse and sizeable dance community has been emerging in VRChat. Little is known about these dancers’ experiences, motivations, and practices. Yet shedding light into these could inform both VR technology development and the design of systems that better support embodied and complex social interactions. To bridge this gap, we interviewed participants active in the VRChat dance scene. Through thematic analysis, we identified six central facets of their experiences related to freedom, community, dance as an individual experience, dance as a shared experience, dance as a performance, and self-expression and -exploration. Based on these findings, we discuss emerging tensions and highlight beneficial impacts of dancing in VR as well as problems that still await resolving.
Simulator sickness has been one of the major obstacles toward making virtual reality (VR) widely accepted and used.
For example, virtual navigation produces vection, which is the illusion of self-motion as one perceives bodily motion despite no movement actually occurs.
This, in turn, causes a sensory conflict between visual and actual (or vestibular) motion and sickness.
In this study, we explore a method to reduce simulator sickness by visually mixing the optical flow patterns that are in the reverse direction of the virtual visual motion.
As visual motion is mainly detected and perceived by the optical flow, artificial mixing in the reverse flow is hypothesized to induce a cancellation effect, thereby reducing the degree of the conflict with the vestibular sense and sickness.
To validate our hypothesis, we developed a real-time algorithm to visualize the reverse optical flow and conducted experiments by comparing the before and after sickness levels in seven virtual navigation conditions.
The experimental results confirmed the proposed method was effective for reducing the simulator sickness in a statistically significant manner.
However, no dependency to the motion type or degrees of freedom were found.
Significant distraction and negative influence to the sense of presence and immersion were observed
only when the the artificially added reverse optical flow patterns were rather visually marked with high contrast to the background content.