Throwing is a fundamental movement in many sports and games. Given this, accurate throwing in VR applications today is surprisingly difficult. In this paper we explore the nature of the difficulties of throwing in VR in more detail. We present the results of a user study comparing throwing in VR and in the physical world. In a short pre-study with 3 participants we determine an optimal number of throwing repetitions for the main study by exploring the learning curve and subjective fatigue of throwing in VR. In the main study, with 12 participants, we find that throwing precision and accuracy in VR are lower particularly in the distance and height dimensions. It also requires more effort and exhibits different kinematic patterns.
Virtual and augmented reality head-mounted displays (HMDs) are currently heavily relying on spatially tracked input devices (STID) for interaction. These STIDs are all prone to the phenomenon that a discrete input (e.g. button press) will disturb the position of the tracker, resulting in a different selection point during ray-cast interaction (Heisenberg Effect of Spatial Interaction). Besides the knowledge of its existence, there is currently a lack of a deeper understanding of its severity, structure and impact on throughput and angular error during a selection task. In this work, we present a formal evaluation of the Heisenberg effect and the impact of body posture, arm position and STID degrees of freedom on its severity. In a Fitt's Law inspired user study (N=16), we found that the Heisenberg effect is responsible for 30.45% of the overall errors occurring during a pointing task, but can be reduced by 25.4% using a correction function.
We introduce VR Strider, a novel locomotion user interface (LUI) for seated virtual reality (VR) experiences, which maps cycling biomechanics of the user's legs to virtual walking movements. The core idea is to translate the motion of pedaling on a mini exercise bike to a corresponding walking animation of a virtual avatar while providing audio-based tactile feedback on virtual ground contacts. We conducted an experiment to evaluate the LUI and our novel anchor-turning rotation control method regarding task performance, spatial cognition, VR sickness, sense of presence, usability and comfort in a path-integration task. The results show that VR Strider has a significant positive effect on the participants' angular and distance estimation, sense of presence and feeling of comfort compared to other established locomotion techniques, such as teleportation and joystick-based navigation. A confirmatory study further indicates the necessity of synchronized avatar animations for virtual vehicles that rely on pedalling.
We propose using virtual reality (VR) as a design tool for sketching and simulating spatially-aware interactive spaces. Using VR, designers can quickly experience their envisioned spaces and interactions by simulating technologies such as motion tracking, multiple networked devices, or unusual form factors such as spherical touchscreens or bezel-less display tiles. Design ideas can be rapidly iterated without restrictions by the number, size, or shape and availability of devices or sensors in the lab. To understand the potentials and challenges of designing in VR, we conducted a user study with 12 interaction designers. As their tool, they used a custom-built virtual design environment with finger tracking and physics simulations for natural interactions with virtual devices and objects. Our study identified the designers' experience of space in relation to their own bodies and playful design explorations as key opportunities. Key challenges were the complexities of building a usable yet versatile VR-based "World Editor".
Augmented Reality can provide orientation and awareness in situations in which objects or people are occluded by physical structures. This is relevant for many situations in the workplace, where objects are scattered across rooms and people are out of sight. While several AR mechanisms have been proposed to provide awareness and orientation in these situations, little is known about their effect on people's performance when searching objects and coordinating with each other. In this paper, we compare three AR based mechanisms (map, x-ray, compass) according to their utility, usability, social presence, task load and users' preferences. 48 participants had to work together in groups of four to find people and objects located around different rooms. Results show that map and x-ray performed best but provided least social presence among participants. We discuss these and other observations as well as potential impacts on designing AR awareness and orientation support.