Freehand-Steering Locomotion Techniques for Immersive Virtual Environments: A Comparative Evaluation

Virtual reality has achieved significant popularity in recent years, and allowing users to move freely within an immersive virtual world has become an important factor critical to realize. The user’s interactions are generally designed to increase the perceived realism, but the locomotion techniques and how these affect the user’s task performance still represent an open issue, much discussed in the literature. In this article, we evaluate the efficiency and effectiveness of, and user preferences relating to, freehand locomotion techniques designed for an immersive virtual environment performed through hand gestures tracked by a sensor placed in the egocentric position and experienced through a head-mounted display. Three freehand locomotion techniques have been implemented and compared with each other, and with a baseline technique based on a controller, through qualitative and quantitative measures. An extensive user study conducted with 60 subjects shows that the proposed methods have a performance comparable to the use of the controller, further revealing the users’ preference for decoupling the locomotion in sub-tasks, even if this means renouncing precision and adapting the interaction to the possibilities of the tracker sensor

DEVELOPMENT OF A PROTOTYPE VIRTUAL REALITY TRAINER FOR TACTICAL VEHICLE GROUND-GUIDING PROCEDURES

The use of virtual reality (VR) technology in the training domain brings several benefits to the training force: compared to training in the real world, VR training reduces logistical support, it eliminates high-risk safety situations, and it enables scenarios not possible otherwise. This work determines the viability of using commercial off-the-shelf technology (COTS) to develop a prototype VR trainer in support of tactical vehicle ground-guiding procedures. A task analysis was conducted to identify all steps of the task in which an individual used hand and arm signals to communicate directions and position to another individual who operated a tactical vehicle. This work was used to define elements of human performance and system requirements, and to develop a multiuser VR training system. A total of eighteen subjects participated in a user study to evaluate usability of the system. The prototype system was able to fully immerse the subjects with visual, aural, and haptic displays, successfully blocking out influences from the real world to a sufficient extent that subjects believed they were in the virtual world and could perform ground-guiding operations. Given the subjects’ responses in the Standardized Usability Scale questionnaire, the system was seen as a viable tool for training of ground-guiding procedures. The results of this study demonstrated that it is feasible to use COTS technology and create a prototype system for training in ground-guiding and driving skills.http://archive.org/details/developmentofapr1094562303Captain, United States Marine CorpsApproved for public release; distribution is unlimited

Towards Naturalistic Interfaces of Virtual Reality Systems

Interaction plays a key role in achieving realistic experience in virtual reality (VR). Its realization depends on interpreting the intents of human motions to give inputs to VR systems. Thus, understanding human motion from the computational perspective is essential to the design of naturalistic interfaces for VR. This dissertation studied three types of human motions, including locomotion (walking), head motion and hand motion in the context of VR. For locomotion, the dissertation presented a machine learning approach for developing a mechanical repositioning technique based on a 1-D treadmill for interacting with a unique new large-scale projective display, called the Wide-Field Immersive Stereoscopic Environment (WISE). The usability of the proposed approach was assessed through a novel user study that asked participants to pursue a rolling ball at variable speed in a virtual scene. In addition, the dissertation studied the role of stereopsis in avoiding virtual obstacles while walking by asking participants to step over obstacles and gaps under both stereoscopic and non-stereoscopic viewing conditions in VR experiments. In terms of head motion, the dissertation presented a head gesture interface for interaction in VR that recognizes real-time head gestures on head-mounted displays (HMDs) using Cascaded Hidden Markov Models. Two experiments were conducted to evaluate the proposed approach. The first assessed its offline classification performance while the second estimated the latency of the algorithm to recognize head gestures. The dissertation also conducted a user study that investigated the effects of visual and control latency on teleoperation of a quadcopter using head motion tracked by a head-mounted display. As part of the study, a method for objectively estimating the end-to-end latency in HMDs was presented. For hand motion, the dissertation presented an approach that recognizes dynamic hand gestures to implement a hand gesture interface for VR based on a static head gesture recognition algorithm. The proposed algorithm was evaluated offline in terms of its classification performance. A user study was conducted to compare the performance and the usability of the head gesture interface, the hand gesture interface and a conventional gamepad interface for answering Yes/No questions in VR. Overall, the dissertation has two main contributions towards the improvement of naturalism of interaction in VR systems. Firstly, the interaction techniques presented in the dissertation can be directly integrated into existing VR systems offering more choices for interaction to end users of VR technology. Secondly, the results of the user studies of the presented VR interfaces in the dissertation also serve as guidelines to VR researchers and engineers for designing future VR systems

The Effect of Prior Virtual Reality Experience on Locomotion and Navigation in Virtual Environments

VirtualReality(VR) is becoming more accessible and widely utilized in crucial disciplines like training, communication, healthcare, and education. One of the important parts of VR applications is walking through virtual environments. So, researchers have broadly studied various kinds of walking in VR as it can reduce sickness, improve the sense of presence, and enhance the general user experience. Due to the recent availability of consumer Head Mounted Displays (HMDs), people are using HMDs in all sorts of different locations. It underscores the need for locomotion methods that allow users to move through large Immersive Virtual Environments (IVEs) when occupying a small physical space or even seated. Although many aspects of locomotion in VR have received extensive research, very little work has considered how locomotive behaviors might change over time as users become more experienced in IVEs. As HMDs were rarely encountered outside of a lab before 2016, most locomotion research before this was likely conducted with VR novices who had no prior experience with the technology. However, as this is no longer the case, itis important to consider whether locomotive behaviors may evolve over time with user experience. This proposal specifically studies locomotive behaviors and effects that may adjust over time. For the first study, we conducted experiments measuring novice and experienced subjects’ gait parameters in VR and real environments. Prior research has established that users’ gait in virtual and real environments differs; however, little research has evaluated how users’ gait differs as users gain more experience with VR. We conducted experiments measuring novice and experienced subjects’ gait parameters in VR and real environments. Results showed that subjects’ performance in VR and Real World was more similar in the last trials than in the first trials; their walking dissimilarity in the start trials diminished by walking more trials. We found the trials a significant variable affecting the walking speed, step length, and trunk angle for both groups of users. While the main effect of expertise was not observed, an interaction effect between expertise and the trial number was shown. The trunk angle increased over time for novices but decreased for experts. These cond study reports the results of an experiment investigating how users’ behavior with two locomotion methods changed over four weeks: teleportation and joystick-based locomotion. Twenty novice VR users (no more than 1 hour prior experience with any form of walking in VR) were recruited. They loaned an Oculus Quest for four weeks on their own time, including an activity we provided them with. Results showed that the time required to complete the navigation task decreased faster for joystick-based locomotion. Spatial memory improved with time, particularly when using teleportation (which starts disadvantaged to joystick-based locomotion). Also, overall cyber sickness decreased slightly overtime; two dimensions of cyber sickness (nausea and disorientation) increased notably over time using joystick-based navigation. The next study presents the findings of a longitudinal research study investigating the effects of locomotion methods within virtual reality on participants’ spatial awareness during VR experiences and subsequent real-world gait parameters. The study encompasses two distinct environments: the real world and VR. In the real world setting, we analyze key gait parameters, including walking speed, distance traveled, and stepcount, both pre and post-VR exposure, to perceive the influence of VR locomotion on post-VR gait behavior. Additionally, we assess participants’ spatial awareness and the occurrence of simulator sickness, considering two locomotion methods: joy stick and teleportation. Our results reveal significant changes in gait parameters associated with increased VR locomotion experience. Furthermore, we observe a remarkable reduction in cyber sickness symptoms over successive VR sessions, particularly evident among participants utilizing joy stick locomotion. This study contributes to the understanding of gait behavior influenced by VR locomotion technology and the duration of VR immersion. Together, these studies inform how locomotion and navigation behavior may change in VR as users become more accustomed to walking in virtual reality settings. Also, comparative studies on locomotion methods help VR developers to implement the better-suited locomotion method. Thus, it provides knowledge to design and develop VR systems to perform better for different applications and groups of users