Edited for Working Group 2 (WG 2): Cisigraph, Cranfield Institute of Technology, Danmarks Tekniske Hojskole, Kernforschungszentrum Karlsruhe GmbH, NEH Consulting Engineers ApS, Universität Karlsruhe

1.1 PURPOSE The purpose of this paper is to document the results of Working Group (wireframes), Working Group 2 (solids) ,and Working Group 3 (surfaces) of the ESPRIT project 322 CAD*I (CAD Interfaces). The goal of these working groups is: 1. Develop a neutral file format for transfer of CAD data (curves, surfaces, and solid models) between CAD systems, and from the CAD domain to CAA (computer aided analysis) and CAM (computer aided manufacturing). 2. Develop pre- and post-processors with a number of representative CAD systems for this neutral file format. 3. Develop representative test model files and perform cycle tests and inter-system tests for CAD model transfer. 4. Contribute to the standardization activities in the national standardi zation bodies and in ISO for the establishment of a neutral file format for CAD data. This paper corresponds to a development stage as it was reached on July 6, 1987.

Principal authors: U. Kroszynski, B. Palstr9Sm 1.1 The evolution of concepts and specifications for CAD data exchange The CAD/CAM community has witnessed, during the last decade, the appearance of several specifications as well as proposals for standards which either attempt to cover wider areas or to be more reliable and stable than the others. With the rapid evolution of both hardware and software, the capabilities offered by CAD systems and CAD based application systems are far more advanced than they were only ten years ago, even when they are now based on micro-computers or personal comput ers. The situation with standards, however, is not and cannot be so. In order to be reliable and accepted by a wide community of both vendors and users, a standard has to be sta ble. This implies a life span of at least a decade. This also implies that the standard has to be general and flexible enough to accommodate present as well as expected future developments. 1.1.1 IGES The initial development of concepts for CAD data exchange is strongly influenced by the US Integrated Computer Aided Manufacturing (ICAM) programme, that dealt with the development of methods for data exchange. In September 1979, a subgroup was estab lished with participation of the National Bureau of Standards, the General Electric Com pany, and the Boeing Company. The result of this effort was the Initial Graphics Exchange Specification (IGES) that was published as a NBS report [61] in 1980.

A classic examination of superb design through the centuries. Widely regarded as a classic in the field, Experiencing Architecture explores the history and promise of good design. Generously illustrated with historical examples of designing excellence—ranging from teacups, riding boots, and golf balls to the villas of Palladio and the fish-feeding pavilion of Beijing's Winter Palace—Rasmussen's accessible guide invites us to appreciate architecture not only as a profession, but as an art that shapes everyday experience. In the past, Rasmussen argues, architecture was not just an individual pursuit, but a community undertaking. Dwellings were built with a natural feeling for place, materials and use, resulting in “a remarkably suitable comeliness.” While we cannot return to a former age, Rasmussen notes, we can still design spaces that are beautiful and useful by seeking to understand architecture as an art form that must be experienced. An understanding of good design comes not only from one's professional experience of architecture as an abstract, individual pursuit, but also from one's shared, everyday experience of architecture in real time—its particular use of light, color, shape, scale, texture, rhythm and sound. Experiencing Architecture reminds us of what good architectural design has accomplished over time, what it can accomplish still, and why it is worth pursuing. Wide-ranging and approachable, it is for anyone who has ever wondered “what instrument the architect plays on.”