or processes are modified by designers in the CAD system, a substantial amount of time may be required to reflect the appropriate changes in the manufacturing documentation. The augmented-reality system would link manufacturing instructions with the CAD system and superimpose these instructions in the form of diagrams on work pieces. The diagrams would appear to be painted on. For each step, a new diagram is projected. The link with the CAD system would make it possible to show changes in design or procedures to the worker immediately. A more detailed description of this project is provided by Caudell and Mizell (1992).
Technology Requirements In Boeing's augmented-reality project, a prototype system has been developed and tested. The primary technology needs are for a comfortable head-mounted color display with a field of view wider than 30 degrees. Another goal is a position-tracking system that will leave the worker untethered.
In order to implement Boeing's vision for using VE, several areas require technology development. One critical problem is the lack of graphics and computing power. The CAD database for the 777 aircraft contains between 5 and 10 billion polygons. Even though only a fraction of the database may be needed at any one time, the existing graphics hardware limits the ability to create a scene that is interactive in real time, particularly because of the complexity of the geometry in the CAD database. The problems created by the size of the database, the inadequate hardware, and the requirement for a VE that looks real and behaves in predictable ways underscore the need for research on real-time scheduling, assigning reduced workload areas, and developing heuristics to accomplish graceful degradation.
Another goal requiring technology development is providing engineers with the ability to interact with objects in virtual space. Currently, Boeing is working with a mannequin developed by Norman Badler at the University of Pennsylvania (Badler et al., 1993) that can be put inside the CAD geometry and changed in size or shape. Similar technology has been used by the automobile industry for several years. The next major step is to develop the capability for an engineer to inhabit the mannequin in a virtual space, to move around inside the CAD geometry, perform maintenance checks, and in general, feel present inside the scene while others monitor from a third person. Particularly important development areas include the need for collision detection and the requirement to give the individual in the virtual space some sense of force feedback, especially when testing the difficulty of performing various maintenance operations. Developments in this area, particularly those involving haptic feedback, are at least 10 to 15 years in the future.
Creating architectural walkthroughs of customized aircraft interiors