Jim Durbin

User-centered design and evaluation of a real-time battlefield visualization virtual environment

The ever-increasing power of computers and hardware rendering systems has, to date, primarily motivated the creation of visually rich and perceptually realistic virtual environment (VE) applications. Comparatively very little effort has been expended on the user interaction components of VEs. As a result, VE user interfaces are often poorly designed and are rarely evaluated with users. Although usability engineering is a newly emerging facet of VE development, user-centered design and usability evaluation in VEs as a practice still lags far behind what is needed. This paper presents a structured, iterative approach for the user-centered design and evaluation of VE user interaction. This approach consists of the iterative use of expert heuristic evaluation, followed by formative usability evaluation, followed by summative evaluation. We describe our application of this approach to a real-world VE for battlefield visualization, describe the resulting series of design iterations, and present evidence that this approach provides a cost-effective strategy for assessing and iteratively improving user interaction design in VEs. This paper is among the first to report applying an iterative, structured, user-centered design and evaluation approach to VE user interaction design.

Battlefield visualization on the responsive workbench

In this paper we describe a battlefield visualization system, called Dragon, which we have implemented on a virtual reality responsive workbench. The Dragon system has been successfully deployed as part of two large military exercises: the Hunter Warrior advanced warfighting experiment, in March 1997, and the Joint Counter Mine advanced concept tactical demonstration, in August and September 1997. We describe battlefield visualization, the Dragon system, and the workbench, and we describe our experiences as part of these two real-world deployments, with an emphasis on lessons learned and needed future work.

Virtual workbench - a non-immersive virtual environment for visualizing and interacting with 3D objects for scientific visualization

The Virtual Workbench (VW) is a non-immersive virtual environment that allows users to view and interact with stereoscopic objects displayed on a workspace similar to a tabletop workspace used in day-to-day life. A VW is an ideal environment for collaborative work where several colleagues can gather around the table to study 3D virtual objects. The Virtual Reality laboratory at the Naval Research Laboratory has implemented the VW using a concept similar to (Froehlich et al., 1994). This paper investigates how the VW can be used as a non-immersive display device for understanding and interpreting complex objects encountered in the scientific visualization field. Different techniques for interacting with 3D visualization objects on the table and using VW as a display device for visualization are evaluated using several cases.

The software architecture of a real-time battlefield visualization virtual environment

This paper describes the software architecture of Dragon, a real-time situational awareness virtual environment for battlefield visualization. Dragon receives data from a number of different sources and creates a single, coherent, and consistent three-dimensional display. We describe the problem of Battlefield Visualization and the challenges it imposes. We discuss the Dragon architecture, the rational for its design, and its performance in an actual application. The battlefield VR system is also suitable for similar civilian domains such as large-scale disaster relief and hostage rescue.

Situational Awareness Using the Responsive Workbench

Abstract : Our task is to provide situational awareness for the complex logistical task of directing the movement of U.S. Marines and material over rugged terrain, day and night, in uncertain weather conditions. This difficulty is multiplied by the well-known dangers of amphibious assault, long considered the most difficult problem in warfare. Even with the advent of computers and sophisticated decision-making software in Marine Corps Combat Operation Centers, command and control is predominantly undertaken with paper maps and acetate overlays. This is a cumbersome, time consuming process. In addition, detailed maps and overlays can take several hours to print and distribute. There currently exists no overall picture of the battlespace that provides a commander with a dynamic range of resolution sufficient to track units ranging from aircraft carriers to six-Marine fire teams.

Amortizing 3D graphics optimization across multiple frames

Abstract : This paper describes a mechanism for improving rendering rates dynamically during runtime in an interactive three-dimensional graphics application. Well-known techniques such as transforming hierarchical geometry into a flat list and removing redundant graphics primitives are often performed off-line on static databases, or continuously every rendering frame. In addition, these optimizations are usually performed over the whole database. We observe that much of the database remains static for a fixed period of time, while other portions are modified continuously (e.g. the camera position), or are repeatedly modified during some finite interval (e.g. during user interaction). We have implemented a runtime optimization mechanism which is sensitive to repeated, local database changes. This mechanism employs timing strategies which optimize only when the cost of optimization will be amortized over a sufficient number of frames. Using this optimization scheme, we observe a rendering speedup of roughly 2.5 in existing applications. We discuss our initial implementation of this mechanism, the improved timing measurements, the issues and assumptions we made, and future improvements.

Making information overload work: the Dragon software system on a virtual reality responsive workbench

Gaining a detailed and thorough understanding of the modern battle space is vital to the success of any military operation. Military commanders have access to significant quantities of information which originates from disparate and occasionally conflicting sources and systems. Combining this information into a single, coherent view of the environment can be extremely difficult, error prone and time consuming. In this paper we describe the Naval Research Laboratorys Virtual Reality Responsive Workbench (VRRWB) and Dragon software system which together address the problem of battle space visualization. The VRRWB is a stereoscopic 3D interactive graphics system which allows multiple participants to interact in a shared virtual environment and physical space. A graphical representation of the battle space, including the terrain and military assets which lie on it, is displayed on a projection table. Using a six degree of freedom tracked joystick, the user navigates through the environment and interacts, via selection and querying, with the represented assets and the terrain. The system has been successfully deployed in the Hunter Warrior Advanced Warfighting Exercise and the Joint Countermine ACTD Demonstration One. In this paper we describe the system and its capabilities in detail, discuss its performance in these two operations, and describe the lessons which have been learned.