A Literature Survey for Virtual Environments: Military Flight
29 Oct 2012-
TL;DR: In this article, a survey of the literature in the field of virtual environments (VE) is presented, focusing on military literature that may be hard for traditional academics to locate via the standard journals.
Abstract: Researchers in the field of virtual environments (VE), or virtual reality, surround a participant with synthetic stimuli, The flight simulator community, primarily in the U.S. military, has a great deal of experience with aircraft simulations, and VE researchers should be aware of the major results in this field. In this survey of the literature, we have especially focused on military literature that may be hard for traditional academics to locate via the standard journals. One of the authors of this paper is a military helicopter pilot himself, which was quite useful in obtaining access to many of our references. We concentrate on research that produces specific, measured results that apply to VE research. We assume no background other than basic knowledge of computer graphics, and explain simulator terms and concepts as necessary. This paper ends with an annotated bibliography of some harder to find research results in the field of flight simulators: • The effects of display parameters, including field-of-view and scene complexity; • The effect of lag in system response; • The effect of refresh rate in graphics update; • The existing theories on causes of simulator sickness; and • The after-effects of simulator use Many of the results we cite are contradictory. Our global observation is that with flight simulator research, like most human-computer interaction research, there are very few correct answers. Almost always, the answer to a specific question depends on the task the user was attempting to perform with the simulator.
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Dissertation•
15 Feb 2017
TL;DR: The described methods and studies show that gaze-contingent algorithms are able to improve the quality of displayed images and videos or reduce the computational effort for image generation, while display quality perceived by the user does not change.
Abstract: Contemporary digital displays feature multi-million pixels at ever-increasing refresh rates. Reality, on the other hand, provides us with a view of the world that is continuous in space and time. The discrepancy between viewing the physical world and its sampled depiction on digital displays gives rise to perceptual quality degradations. By measuring or estimating where we look, gaze-contingent algorithms aim at exploiting the way we visually perceive to remedy visible artifacts. This dissertation presents a variety of novel gaze-contingent algorithms and respective perceptual studies. Chapter 4 and 5 present methods to boost perceived visual quality of conventional video footage when viewed on commodity monitors or projectors. In Chapter 6 a novel head-mounted display with real-time gaze tracking is described. The device enables a large variety of applications in the context of Virtual Reality and Augmented Reality. Using the gaze-tracking VR headset, a novel gaze-contingent render method is described in Chapter 7. The gaze-aware approach greatly reduces computational efforts for shading virtual worlds. The described methods and studies show that gaze-contingent algorithms are able to improve the quality of displayed images and videos or reduce the computational effort for image generation, while display quality perceived by the user does not change.
11 citations
01 Nov 1981
TL;DR: In this article, four different visual displays were evaluated for their effectiveness in the acquisition of flight tasks in a simulator, including a narrow field-of-view with horizon and checkerboard ground plane; an outside viewpoint of an aircraft; and display that consisted only of normal flight instruments.
Abstract: : Use of simulators for flight instruction has typically followed the pattern of using similar instructional approaches to those that have traditionally been used for in-flight instruction. However, there is a growing awareness that a simulator permits radical departures from the traditional methods. Some of these may be less expensive or even more effective in terms of acquiring the skill. The general purpose of the research reported here was to examine training effectiveness for basic flight tasks of radically different methods of displaying the information that is necessary to support learning of the tasks. Four different visual displays were evaluated for their effectiveness in the acquisition of flight tasks in a simulator. The control condition had a wide field-of-view, a horizon and a checkerboard ground plane that obeyed laws of motion and perspective. The experimental displays were: (1) a narrow field-of-view with horizon and checkerboard ground plane; (2) an outside viewpoint of an aircraft; and (3) a display that consisted only of normal flight instruments. Flight-naive subjects were taught to fly straight-and-level for twenty trials with either the control or one of the experimental displays and then tested for twenty trials on the control display. Training, transfer, and differential transfer performance was examined.
7 citations
01 Apr 1974
TL;DR: A broad program of simulation research with emphasis on engineering and behavior is suggested toward the goal of improving aircrew performance.
Abstract: : The paper outlines some major areas of use of simulation in Army Aviation and comments on current research. Equipment development, crew performance studies, concept development and training are discussed. Only in the training area has the Army made substantial progress. A broad program of simulation research with emphasis on engineering and behavior is suggested toward the goal of improving aircrew performance. There are significant simulation research problems unique to the Army which need to be worked out. (Author)
7 citations
01 Feb 1997
TL;DR: In this article, the authors explored a synthetic representation of an Army heliport under three visual display conditions: (1) wide field-of-view (FOV) helmet mounted display, (2) narrow FOV helmet-mounted display, and (3) stationary, wide screen display.
Abstract: : Soldiers explored a synthetic representation of an Army heliport under three visual display conditions: (1) wide field of view (FOV) helmet mounted display, (2) narrow FOV helmet mounted display, and (3) stationary, wide screen display. Pretest and posttest measures of spatial knowledge were recorded. Measures of presence in the virtual environment were recorded. Measures of simulator sickness were administered upon exit from the virtual environment and 24 hours later. Overall, soldiers acquired a significant amount of spatial knowledge from the synthetic representation. When transferred to the actual Army heliport, soldiers were able to navigate around the location with near zero errors. There was no effect of visual display on any measures of spatial knowledge. Also, there was no effect of visual display on reported presence or simulator sickness. Simulator sickness was significantly reduced after 24 hours away from the virtual environment. Presence did not correlate with spatial knowledge. Simulator sickness correlated negatively with spatial knowledge. Presence and simulator sickness were negatively correlated.
6 citations
Dissertation•
11 Jun 1998TL;DR: Cette evolution se fera, c’est sur, mais il est pour l’instant plus raisonnable de voir la realite virtuelle comme un complement de the CAO.
Abstract: Nous presentons dans ce memoire l’etude et la realisation d’un systeme interactif pour le prototypage cooperatif de maquettes virtuelles. Ces travaux font usage de plusieurs technologies issues de milieux scientifiques varies ; la realite virtuelle n’est elle pas a la croisee des chemins de nombreuses disciplines ? Notre objectif n’est pas de remplacer des a present un systeme de CAO par un systeme tel que celui que nous proposons dans ce memoire. En effet, la puissance des machines ne permet pas encore la gestion d’objets virtuels avec une precision comparable a celle des outils de CAO. Certes notre systeme est intuitif et interactif mais il ne dispose pas d’assez de puissance machine pour rivaliser en precision avec de tels outils ; cette precision est pourtant necessaire pour l’industrie. Cette evolution se fera, c’est sur, mais il est pour l’instant plus raisonnable de voir la realite virtuelle comme un complement de la CAO.
6 citations
References
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TL;DR: The characteristics of augmented reality systems are described, including a detailed discussion of the tradeoffs between optical and video blending approaches, and current efforts to overcome these problems are summarized.
Abstract: This paper surveys the field of augmented reality AR, in which 3D virtual objects are integrated into a 3D real environment in real time. It describes the medical, manufacturing, visualization, path planning, entertainment, and military applications that have been explored. This paper describes the characteristics of augmented reality systems, including a detailed discussion of the tradeoffs between optical and video blending approaches. Registration and sensing errors are two of the biggest problems in building effective augmented reality systems, so this paper summarizes current efforts to overcome these problems. Future directions and areas requiring further research are discussed. This survey provides a starting point for anyone interested in researching or using augmented reality.
8,053 citations
TL;DR: A number of the primary factors that contribute to the cause of cybersickness are discussed, three conflicting cybersickenness theories that have been postulated are described, and some possible methods for reducing cyberedickness in VEs are discussed.
Abstract: An important and troublesome problem with current virtual environment (VE) technology is the tendency for some users to exhibit symptoms that parallel symptoms of classical motion sickness both during and after the VE experience. This type of sickness, cybersickness, is distinct from motion sickness in that the user is often stationary but has a compelling sense of self motion through moving visual imagery. Unfortunately, there are many factors that can cause cybersickness and there is no foolproof method for eliminating the problem. In this paper, I discuss a number of the primary factors that contribute to the cause of cybersickness, describe three conflicting cybersickness theories that have been postulated, and discuss some possible methods for reducing cybersickness in VEs.
1,031 citations
TL;DR: A method for approximating polyhedral objects to support a time-critical collision-detectional algorithm that maintains its real-time performance as objects become more complicated, even as they exceed previouslyreported complexity levels by a factor of more than 10.
Abstract: This article presentsa method for approximatingpolyhedralobjects to support a time-critical collision-detectionalgorithm. The approximationsare hierarchies of spheres, and they allow the time-critical algorithm to progressivelyrefine the accuracy of its detection, stopping as needed to maintain the real-time performanceessential for interactive applications.The key to this approachis a preprocessthat automaticallybuilds tightly fitting hierarchies for rigid and articulatedobjects.The preprocessuses medial-axis surfaces, which are skeletal representations of objects. These skeletonsguide an optimizationtechniquethat gives the hierarchies accuracy properties appropriate for collision detection. In a sample application, hierarchies built this way allow the time-criticalcollision-detectionalgorithmto have acceptableaccuracy, improving significantly on that possible with hierarchies built by previous techniques. The performanceof the time-critical algorithmin this application is consistently 10 to 100 times better than a previous collision-detection algorithm, maintaining low latency and a nearIy constant frame rate of 10 frames per second on a conventional graphics workstation. The time-critical algorithm maintains its real-time performanceas objects become more complicated, even as they exceed previouslyreported complexitylevels by a factor of more than 10.
564 citations
TL;DR: The challenges each of these factors present to the effective design of virtual environments and systematic approaches to the resolution of each of them are discussed.
Abstract: Virtual environments are envisioned as being systems that will enhance the communication between humans and computers. If virtual systems are to be effective and well received by their users, considerable human-factors research needs to be accomplished. This paper provides an overview of many of these human-factors issues, including human performance efficiency in virtual worlds (which is likely influenced by task characteristics, user characteristics, human sensory and motor physiology, multimodal interaction, and the potential need for new design metaphors); health and safety issues (of which cybersickness and deleterious physiological aftereffects may pose the most concern); and the social impact of the technology. The challenges each of these factors present to the effective design of virtual environments and systematic approaches to the resolution of each of these issues are discussed.
549 citations
19 Mar 2016
TL;DR: By strategically and automatically manipulating FOV during a VR session, the degree of VR sickness perceived by participants can be reduced and help them adapt to VR, without decreasing their subjective level of presence, and minimizing their awareness of the intervention.
Abstract: Virtual Reality (VR) sickness can cause intense discomfort, shorten the duration of a VR experience, and create an aversion to further use of VR. High-quality tracking systems can minimize the mismatch between a user's visual perception of the virtual environment (VE) and the response of their vestibular system, diminishing VR sickness for moving users. However, this does not help users who do not or cannot move physically the way they move virtually, because of preference or physical limitations such as a disability. It has been noted that decreasing field of view (FOV) tends to decrease VR sickness, though at the expense of sense of presence. To address this tradeoff, we explore the effect of dynamically, yet subtly, changing a physically stationary person's FOV in response to visually perceived motion as they virtually traverse a VE. We report the results of a two-session, multi-day study with 30 participants. Each participant was seated in a stationary chair, wearing a stereoscopic head-worn display, and used control and FOV-modifying conditions in the same VE. Our data suggests that by strategically and automatically manipulating FOV during a VR session, we can reduce the degree of VR sickness perceived by participants and help them adapt to VR, without decreasing their subjective level of presence, and minimizing their awareness of the intervention.
383 citations