Evolution of Computer Aided Design: Three Generations of CAD

This paper describes the three generations of CAD systems. The first generation of (primarily analytical) computer programmes really aided designing. These programmes were the tools for finding a functional solution in different areas of designing, from flat plans to the space organisation of a hospital. One of the shortcomings of these programmes was the lack of graphic interface. With time, however, this kind of interface was developed. As a result of this second generation of CAD systems the computer was transformed into a drafting machine and CAD meant Computer Aided Drafting. The main thesis of this consideration is that only now we have the chance to return to the idea of Computer Aided Design. One of the examples of these trends is the AVOCAAD programme in which Added Value of CAAD is analysed. The development of the third generation of CAD systems will be possible in the near future. Aiding the process of designing will demand the elaboration of new methods of using the computer at the early stages of this process. The computer should be used not for generating variants of functional solutions only but for also for the creation of 3D forms by 3D sketching. For this, the computer should be transformed from a tool into a medium; only then will designing become true Designing in Cyber Space.