Importance of Device Independence to the CADCAM Industry

One of the most challenging problems facing developers and system integrators in the computer-aided design field today is the ever-growing influx of new sophisticated graphics display devices offering a broad range of capabilities. While such devices give users efficient, cost-effective ways to produce the exact graphic output they need, they bring with them the ongoing problem of software portability. Designers who can find ways to insure that their systems are device independent, that is, will run on new devices with little or no modification, will have a definite advantage in developing graphics application software. Device independence implies that a single application program will produce similar perhaps identical images on more than one graphics device. For example, a systems integrator might develop an interactive design application on a storage tube terminal, even though the application will eventually be targeted to a beam-directed or color raster display. Graphics can be built, viewed, and altered at an interactive graphics terminal, with eventual hard-copy output routed to an offline plotter or microfilm recorder. In short, device independence means that graphics application software is not bound to a particular manufacturer\´s equipment. "Device intelligence" extends the principles of device independence to take advantage of the sophisticated hardware and firmware capabilities built into today\´s graphics terminals and graphics workstations. With device intelligence, graphics functions (e.g., creating and filling polygons, controlling the visibility of parts of the picture, copying objects from one area of the screen to another area of the screen, and manipulating objects in real time on the display surface) are performed within the graphics terminal wherever possible. Functions that cannot be performed directly in hardware (e.g., polygon fill on a storage tube), are simulated in software. Finally, requested functions that are impossible or impractical to perform on the target device are ignored (e.g., color on a monochromatic device). This seminar will provide attendees with sufficient information to intelligently evaluate, select, or specify a device-independent computer graphics software package appropriate to the needs of the CAD/CAE community- . Functional capabilities of graphics software will be reviewed and the terminology and concepts of device-independent software will be presented. A partial list of these concepts includes: system architectures, virtual device interfaces, graphics data structures, device independence in the highly interactive environment, device drivers, and graphics metafiles. Trends in graphics hardware and graphics software will also be discussed along with an analysis of the effect of intelligent workstations on the CAD/CAE marketplace. This seminar is aimed at managers, technical personnel, and system integrators considering the purchase, adoption, or development of a device-independent computer graphics subroutine package.