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Proceedings of the 1993 Conference on Intelligent Computer-Aided Training and Virtual Environment Technology

The volume 2 proceedings from the 1993 Conference on Intelligent Computer-Aided Training and Virtual Environment Technology are presented. Topics discussed include intelligent computer assisted training (ICAT) systems architectures, ICAT educational and medical applications, virtual environment (VE) training and assessment, human factors engineering and VE, ICAT theory and natural language processing, ICAT military applications, VE engineering applications, ICAT knowledge acquisition processes and applications, and ICAT aerospace applications.

Hyde, Patricia R.↗

The Ames Virtual Environment Workstation: Implementation issues and requirements

This presentation describes recent developments in the implementation of a virtual environment workstation in the Aerospace Human Factors Research Division of NASA's Ames Research Center. Introductory discussions are presented on the primary research objectives and applications of the system and on the system's current hardware and software configuration. Principle attention is then focused on unique issues and problems encountered in the workstation's development with emphasis on its ability to meet original design specifications for computational graphics performance and for associated human factors requirements necessary to provide compelling sense of presence and efficient interaction in the virtual environment.

Fisher, Scott S.↗

Implementation and integration of a counterbalanced CRT-based stereoscopic display for interactive viewpoint control in virtual environment applications

The NASA-Ames Counterbalanced CRT-based Stereoscopic Viewer (CCSV), which is being used as a viewing device for biomechanical CAD environments, is uniquely suited for applications in which the user frequently moves between desk work and virtual environment viewing, or in which high resolution views of the virtual environment are required, or in which the viewing device must be shared among collaborators in a group setting. The CCSV hardware encompasses a dual-CRT-based stereoscopic viewer with wide-angle optics, a video electronics box, a dedicated microprocessor system monitoring joint angles in the linkage, and a host computer interpreting sensor values and running the application which renders the right and left views for reader CRTs.

Mcdowall, I. E.↗

Human Motion Tracking and Glove-Based User Interfaces for Virtual Environments in ANVIL

The Army/NASA Virtual Innovations Laboratory (ANVIL) at Marshall Space Flight Center (MSFC) provides an environment where engineers and other personnel can investigate novel applications of computer simulation and Virtual Reality (VR) technologies. Among the many hardware and software resources in ANVIL are several high-performance Silicon Graphics computer systems and a number of commercial software packages, such as Division MockUp by Parametric Technology Corporation (PTC) and Jack by Unigraphics Solutions, Inc. These hardware and software platforms are used in conjunction with various VR peripheral I/O (input / output) devices, CAD (computer aided design) models, etc. to support the objectives of the MSFC Engineering Systems Department/Systems Engineering Support Group (ED42) by studying engineering designs, chiefly from the standpoint of human factors and ergonomics. One of the more time-consuming tasks facing ANVIL personnel involves the testing and evaluation of peripheral I/O devices and the integration of new devices with existing hardware and software platforms. Another important challenge is the development of innovative user interfaces to allow efficient, intuitive interaction between simulation users and the virtual environments they are investigating. As part of his Summer Faculty Fellowship, the author was tasked with verifying the operation of some recently acquired peripheral interface devices and developing new, easy-to-use interfaces that could be used with existing VR hardware and software to better support ANVIL projects.

Joseph D. Dumas, II↗

New approaches to virtual environment surgery

This research focused on two main problems: 1) low cost, high fidelity stereoscopic imaging of complex tissues and organs; and 2) virtual cutting of tissue. A further objective was to develop these images and virtual tissue cutting methods for use in a telemedicine project that would connect remote sites using the Next Generation Internet. For goal one we used a CT scan of a human heart, a desktop PC with an OpenGL graphics accelerator card, and LCD stereoscopic glasses. Use of multiresolution meshes ranging from approximately 1,000,000 to 20,000 polygons speeded interactive rendering rates enormously while retaining general topography of the dataset. For goal two, we used a CT scan of an infant skull with premature closure of the right coronal suture, a Silicon Graphics Onyx workstation, a Fakespace Immersive WorkBench and CrystalEyes LCD glasses. The high fidelity mesh of the skull was reduced from one million to 50,000 polygons. The cut path was automatically calculated as the shortest distance along the mesh between a small number of hand selected vertices. The region outlined by the cut path was then separated from the skull and translated/rotated to assume a new position. The results indicate that widespread high fidelity imaging in virtual environment is possible using ordinary PC capabilities if appropriate mesh reduction methods are employed. The software cutting tool is applicable to heart and other organs for surgery planning, for training surgeons in a virtual environment, and for telemedicine purposes.

NASA Discipline Neuroscience↗

A specification of 3D manipulation in virtual environments

In this paper we discuss the modeling of three basic kinds of 3-D manipulations in the context of a logical hand device and our virtual panel architecture. The logical hand device is a useful software abstraction representing hands in virtual environments. The virtual panel architecture is the 3-D component of the 2-D window systems. Both of the abstractions are intended to form the foundation for adaptable 3-D manipulation.

Su, S. Augustine↗

Motion sickness and proprioceptive aftereffects following virtual environment exposure

To study the potential aftereffects of virtual environments (VE), tests of visually guided behavior and felt limb position (pointing with eyes open and closed) along with self-reports of motion sickness-like discomfort were administered before and after 30 min exposure of 34 subjects. When post- discomfort was compared to a pre-baseline, the participants reported more sickness afterward (p < 0.03). The change in felt limb position resulted in subjects pointing higher (p < 0.038) and slightly to the left, although the latter difference was not statistically significant (p = 0.08). When findings from a second study using a different VE system were compared, they essentially replicated the results of the first study with higher sickness afterward (p < 0.001) and post- pointing errors were also up (p < 0.001) and to the left (p < 0.001). While alternative explanations (e.g. learning, fatigue, boredom, habituation, etc.) of these outcomes cannot be ruled out, the consistency of the post- effects on felt limb position changes in the two VE implies that these recalibrations may linger once interaction with the VE has concluded, rendering users potentially physiologically maladapted for the real world when they return. This suggests there may be safety concerns following VE exposures until pre-exposure functioning has been regained. The results of this study emphasize the need for developing and using objective measures of post-VE exposure aftereffects in order to systematically determine under what conditions these effects may occur.

NASA Discipline Neuroscience↗

Emergency Response Virtual Environment for Safe Schools

An intelligent emergency response virtual environment (ERVE) that provides emergency first responders, response planners, and managers with situational awareness as well as training and support for safe schools is presented. ERVE incorporates an intelligent agent facility for guiding and assisting the user in the context of the emergency response operations. Response information folders capture key information about the school. The system enables interactive 3D visualization of schools and academic campuses, including the terrain and the buildings' exteriors and interiors in an easy to use Web..based interface. ERVE incorporates live camera and sensors feeds and can be integrated with other simulations such as chemical plume simulation. The system is integrated with a Geographical Information System (GIS) to enable situational awareness of emergency events and assessment of their effect on schools in a geographic area. ERVE can also be integrated with emergency text messaging notification systems. Using ERVE, it is now possible to address safe schools' emergency management needs with a scaleable, seamlessly integrated and fully interactive intelligent and visually compelling solution.

Wasfy, Ayman↗

Virtual Environment Platform for OT/IT Training Enhancement

TRADITIONAL TECHNIQUES OT/IT Concepts Operational Technology (OT) and Information Technology (IT) concepts can often be difficult to visualize Teaching Methods Traditional teaching methods lack the intuitive & immersive aspects of hands-on activities Caveat: Unless taught by Team B! Physical Limitations Digital Twins require existing systems/hardware to mirror UPDATED TECHNIQUES Virtual Environment By making use of a virtual environment, we can represent abstract concepts in a more approachable and digestible way Increased Engagement Students are more engaged with the activities and are more likely to retain the information they are given. New/Emerging Technologies As the system is currently growing and developing, the technologies in use, as well as those represented by the system, stay up-to-date.

Deroller, Nicholas F.↗

Simulation fidelity of a virtual environment display

We assessed the degree to which a virtual environment system produced a faithful simulation of three-dimensional space by investigating the influence of a pitched optic array on the perception of gravity-referenced eye level (GREL). We compared the results with those obtained in a physical environment. In a within-subjects factorial design, 12 subjects indicated GREL while viewing virtual three-dimensional arrays at different static orientations. A physical array biased GREL more than did a geometrically identical virtual pitched array. However, addition of two sets of orthogonal parallel lines (a grid) to the virtual pitched array resulted in as large a bias as that obtained with the physical pitched array. The increased bias was caused by longitudinal, but not the transverse, components of the grid. We discuss implications of our results for spatial orientation models and for designs of virtual displays.

Nemire, Kenneth↗

Implementation of a three degree of freedom, motor/brake hybrid force output device for virtual environment control tasks

The advent of high resolution, physical model based computer graphics has left a gap in the design of input/output technology appropriate for interacting with such complex virtual world models. Since virtual worlds consist of physical models, it is appropriate to output the inherent force information necessary for the simulation to the user. The detailed design, construction, and control of a three degree freedom force output joystick will be presented. A novel kinematic design allows all three axes to be uncoupled, so that the system inertia matrix is diagonal. The two planar axes are actuated through an offset gimbal, and the third through a sleeved cable. To compensate for friction and inertia effects, this transmission is controlled by a force feedforward and a closed force feedback proportional loop. Workspace volume is a cone of 512 cubic inches, and the device bandwidth is maximized at 60 Hz for the two planar and 30 Hz for the third axis. Each axis is controlled by a motor/proportional magnetic particle brake combination fixed to the base. The innovative use of motors and brakes allows objects with high resistive torque requirements to be simulated without the stability and related safety issues involved with high torque, energy storing motors alone. Position, velocity, and applied endpoint force are sensed directly. Different control strategies are discussed and implemented, with an emphasis on how virtual environment force information, generated by the MIT Media Lab Computer Graphics and Animation Group BOLIO system, is transmitted to the device controller. The design constraints for a kinesthetic force feedback device can be summarized as: How can the symbiosis between the sense of presence in the virtual environment be maximized without compromising the interaction task under the constraints of the mechanical device limitations? Research in this field will yield insights to the optimal human sensory feedback mix for a wide spectrum of control and interaction problems. A flexible research tool that is designed as an easily reproducible product prototype has been constructed to explore the variety of possible force interaction.

Russo, Massimo↗

The virtual windtunnel: Visualizing modern CFD datasets with a virtual environment

This paper describes work in progress on a virtual environment designed for the visualization of pre-computed fluid flows. The overall problems involved in the visualization of fluid flow are summarized, including computational, data management, and interface issues. Requirements for a flow visualization are summarized. Many aspects of the implementation of the virtual windtunnel were uniquely determined by these requirements. The user interface is described in detail.

Bryson, Steve↗

In Situ Measurements of Surface Texture with Virtual Environments Support Science-Driven Human Surface Operations on the Moon and Beyond

Visualization tools enabling real-time scientific analysis are important for supporting future astronaut operations on the lunar surface. Such tools can be built into virtual environments to support scientific investigations, as well as situational awareness, real-time decision making, and efficient communication between astronauts and ground and support systems. Understanding how these tools can be optimized for science is essential for upcoming Artemis missions. In this contribution, we discuss how measurements of surface texture at multiple length scales can greatly enhance in situ science on/of the Moon, and eventually Mars, asteroids, and beyond. Roughness measurements at various wavelengths directly support objectives defined in the Artemis Science Plan, including (O1) “understanding planetary processes,” (O2) “understanding volatile cycles,” and (O3) “interpreting the impact history of the Earth-Moon system” . Key scientific analyses enabled by texture measurements at different length scales include: ● Sub-centimeter scales: Texture measurements can help constrain lava flow crystallinity, lava rheology, emplacement flow dynamics, and cooling histories (O1). Measurements of lacunarity (voids in fractal fill space) can shed light on eruptive volatile content, residence time of migrating volatiles, and near-surface volume available for micro-cold trapping of volatiles (O1, O2). ● Centimeter–meter scales: Texture measurements can be used for the differentiation of individual lava flows, the reconstruction of local stratigraphies and emplacement sequences, characterization of post-emplacement surface modification processes (O1, O3). Derived roughness (polarization) metrics can be used in the detection of water ice and characterization of ice properties (e.g., purity, grade, depth, abundance). ● Hectometer–Kilometer scales: Texture measurements can be used to differentiate major geologic surface units and surface structures (O1), constrain the presence of abundant ground ices (O2), and analyze surface modification and estimate surface age (O3). Real-time measurements of surface texture across these multiple length scales will enable efficient sample identification and scientific investigations by future astronauts. To support these investigations and the objective classification of surface texture, virtual environments employed by astronauts should be able to instantaneously convert raw data into processed data (e.g., digital terrain and elevation models) and derived metrics (e.g., RMS, std, Hurst, CPR) and perform statistical analyses (e.g., PCA, outliers, correlation matrices). Such tools are being developed and tested by the Resource Exploration and Science of our Cosmic Environment (RESOURCE) team, a node of NASA’s Solar System Exploration Research Virtual Institute (SSERVI), and are an excellent example of the powerful synergies of human and robotic ground assets critical in the return of humans to the Moon.

Ariel N. Deutsch↗

Virtual environments for telerobotic shared control

The use of a virtual environment to bring about telerobotic shared control is discussed. A knowledge base, referred to as the World Model, is used to aid the system in its decision making. Information from the World Model is displayed visually in order to aid the human side of human-computer interface.

Christensen, Brian K.↗

Visualization of CFD Results in Immersive Virtual Environments

An object-oriented event-driven immersive virtual environment (VE) is described for the visualization of computational fluid dynamics (CFD) results. The VE incorporates the following types of primitive software objects: interface objects, support objects, geometric entities, and finite elements. The fluid domain is discretized using either a multi-block structured grid or an unstructured finite element mesh. The VE allows natural 'fly-through' visualization of the model, the CFD grid, and the model's surroundings. In order to help visualize the flow and its effects on the model, the VE incorporates the following objects: stream objects (lines, surface-restricted lines. ribbons. and volumes); colored surfaces; elevation surfaces; surface arrows; global and local iso-surfaces; vortex cores; and separation/attachment surfaces and lines. Most of these objects can be used for dynamically probing the flow. Particles and arrow animations can be displayed on top of stream objects. Primitive response quantities as well as derived quantities can be used. A recursive tree search algorithm is used for real-time point and value search in the CFD grid.

Wasfy, Tamer M.↗

SHARED VIRTUAL ENVIRONMENTS FOR COLLECTIVE TRAINING

Historically NASA has trained teams of astronauts by bringing them to the Johnson Space Center in Houston to undergo generic training, followed by mission-specific training. This latter training begins after a crew has been selected for a mission (perhaps two years before the launch of that mission). While some Space Shuttle flights have included an astronaut from a foreign country, the International Space Station will be consistently crewed by teams comprised of astronauts from two or more of the partner nations. The cost of training these international teams continues to grow in both monetary and personal terms. Thus, NASA has been seeking alternative training approaches for the International Space Station program. Since 1994 we have been developing, testing, and refining shared virtual environments for astronaut team training, including the use of virtual environments for use while in or in transit to the task location. In parallel with this effort, we have also been preparing applications for training teams of military personnel engaged in peacekeeping missions. This paper will describe the applications developed to date, some of the technological challenges that have been overcome in their development, and the research performed to guide the development and to measure the efficacy of these shared environments as training tools.

Loftin, R. Bowen↗

Towards Determination of Visual Requirements for Augmented Reality Displays and Virtual Environments for the Airport Tower

The visual requirements for augmented reality or virtual environments displays that might be used in real or virtual towers are reviewed wi th respect to similar displays already used in aircraft. As an example of the type of human performance studies needed to determine the use ful specifications of augmented reality displays, an optical see-thro ugh display was used in an ATC Tower simulation. Three different binocular fields of view (14 deg, 28 deg, and 47 deg) were examined to det ermine their effect on subjects# ability to detect aircraft maneuveri ng and landing. The results suggest that binocular fields of view much greater than 47 deg are unlikely to dramatically improve search perf ormance and that partial binocular overlap is a feasible display tech nique for augmented reality Tower applications.

NATO FURNISHED↗