RedirectedDoors+: Door-Opening Redirection with Dynamic Haptics in Room-Scale VR.

RedirectedDoors is a visuo-haptic door-opening redirection technique in VR, and it has shown promise in its ability to efficiently compress the physical space required for a room-scale VR experience. However, its previous implementation has only supported laboratory experiments with a single door opening at a fixed location. To significantly expand this technique for room-scale VR, we have developed RedirectedDoors+, a robot-based system that permits consecutive door-opening redirection with haptics. Specifically, our system is mainly achieved with the use of three components: (1) door robots, a small number of wheeled robots equipped with a doorknob-like prop, (2) a robot-positioning algorithm that arbitrarily positions the door robots to provide the user with just-in-time haptic feedback during door opening, and (3) a user-steering algorithm that determines the redirection gain for every instance of door opening to keep the user away from the boundary of the play area. Results of simulated VR exploration in six virtual environments reveal our system's performance relative to user walking speed, paths, and number of door robots, from which we derive its usage guidelines. We then conduct a user study ($N=12$) in which participants experience a walkthrough application using the actual system. The results demonstrate that the system is able to provide haptic feedback while redirecting the user within a limited play area.

Exploring Visual-Auditory Redirected Walking using Auditory Cues in Reality.

We examine the effect of auditory cues occurring in reality on redirection. Specifically, we set two hypotheses: the auditory cues emanating from fixed positions in reality (Fixed sound, FS) increase the noticeability of redirection, while the auditory cues whose positions are manipulated consistently with the visual manipulation (Redirected sound, RDS) decrease the noticeability of redirection. To verify these hypotheses, we implemented an experimental environment that virtually reproduced FS and RDS conditions using binaural recording, and then we conducted a user study ( N=18) to investigate the detection thresholds (DTs) for rotational manipulation and the sound localization accuracy of the auditory cues under FS and RDS, as well as the baseline condition without auditory cues (No sound, NS). The results show, against the hypotheses, FS gave a wider range of DTs than NS, while RDS gave a similar range of DTs to NS. Combining these results with those of sound localization accuracy reveals that, rather than the auditory cues affecting the participants' spatial perception in VR, the visual manipulation made their sound localization less accurate, which would be a reason for the increased range of DTs under FS. Furthermore, we conducted a follow-up user study ( N=11) to measure the sound localization accuracy of FS where the auditory cues were actually placed in a real setting, and we found that the accuracy tended to be similar to that of virtually reproduced FS, suggesting the validity of the auditory cues used in this study. Given these findings, we also discuss potential applications.

Reconstruction of Dexterous 3D Motion Data From a Flexible Magnetic Sensor With Deep Learning and Structure-Aware Filtering.

We propose IM3D+, a novel approach to reconstructing 3D motion data from a flexible magnetic flux sensor array using deep learning and a structure-aware temporal bilateral filter. Computing the 3D configuration of markers (inductor-capacitor (LC) coils) from flux sensor data is difficult because the existing numerical approaches suffer from system noise, dead angles, the need for initialization, and limitations in the sensor array's layout. We solve these issues with deep neural networks to learn the regression from the simulation flux values to the LC coils' 3D configuration, which can be applied to the actual LC coils at any location and orientation within the capture volume. To cope with the influence of system noise and the dead-angle limitation caused by the characteristics of the hardware and sensing principle, we propose a structure-aware temporal bilateral filter for reconstructing motion sequences. Our method can track various movements, including fingers that manipulate objects, beetles that move inside a vivarium with leaves and soil, and the flow of opaque fluid. Since no power supply is needed for the lightweight wireless markers, our method can robustly track movements for a very long time, making it suitable for various types of observations whose tracking is difficult with existing motion-tracking systems. Furthermore, the flexibility of the flux sensor layout allows users to reconfigure it based on their own applications, thus making our approach suitable for a variety of virtual reality applications.

GyroWand: An Approach to IMU-Based Raycasting for Augmented Reality.

Optical see-through head-mounted displays enable augmented reality (AR) applications that display virtual objects overlaid on the real world. At the core of this new generation of devices are low-cost tracking technologies that allow us to interpret users' motion in the real world in relation to the virtual content for the purposes of navigation and interaction. The advantages of pervasive tracking come at the cost of limiting interaction possibilities, however. To address these challenges the authors introduce GyroWand, a raycasting technique for AR HMDs using inertial measurement unit (IMU) rotational data from a handheld controller.

3D user interfaces: new directions and perspectives.

Three-dimensional user interfaces (3D UIs) let users interact with virtual objects, environments, or information using direct 3D input in the physical and/or virtual space. In this article, the founders and organizers of the IEEE Symposium on 3D User Interfaces reflect on the state of the art in several key aspects of 3D UIs and speculate on future research.

An interactive stereoscopic display for cooperative work--volume visualization and manipulation with multiple users.

A stereoscopic display table for cooperative work with a volume data is described. Adequate stereoscopic image generated from the volume data is displayed and shared by multiple users. All the users can observe and interact with the volume data displayed on the IllusionHole in a face-to-face environment. It displays each pair of stereoscopic images such that all users observe the 3D image at exactly the same position. An outline of the system is described in this paper.