on the topic of virtual reality. Major professional meetings and trade shows are occurring at a rate of roughly one per month. Over 10 government agencies have held conferences or written reports on VE during the same two-year period. And practically everyone in the field is spending substantial time traveling to other laboratories that are working on VE and providing demonstrations of their own facilities in their own laboratories.
Despite this high talk-to-work or excitement-to-accomplishment ratio, substantial efforts are, in fact, under way in various research and development areas and in various application domains. Significant research and development programs, as well as applications of currently available technology, are being pursued in government, in academia, and in industry. Also, some attempts are being made to develop adequate course material for educational programs in the SE area; however, it is likely to be some time before most academic departments recognize SE as a legitimate field of specialization (e.g., one in which faculty can achieve tenure).
Current research and development efforts directly relevant to the creation of useful SE technology are concerned with (1) computer generation of virtual environments, (2) design of telerobots, (3) improvement of human-machine interfaces, (4) study of relevant aspects of human behavior, and (5) development of communication systems that are adequate to support networking of SE systems. Items (3) and (4) are relevant to all the kinds of systems considered, item (1) to VE systems, item (2) to teleoperation systems, and item (5) to networked systems. An additional item of importance when augmented-reality systems are considered is (6) merging of computer-generated images with images derived directly from the real world.
The "SE Challenge" is related to the High Performance Computing and Communications (HPCC) Grand Challenge program initiated by the federal government through both the computer generation of VEs and networked systems. For many applications, adequate computer generation of the associated virtual worlds is going to require very high-performance computing. Similarly, the networking of SE systems is going to require very high-performance communications. In general, SE systems will provide both a major application area for HPCC and an important source of constraints for the design of HPCC systems.
Currently, the main commercial driving force for the development of VE systems is the entertainment application. There is no equivalent commercial driving force for the development of teleoperators or augmented-reality systems at this time.
Programs on SE technologies and applications are under way in almost every developed country (Thompson, 1993). Major players are the