The computer as a design partner
COMPUTERS are being used more and more in the building industry for a wide variety of applications ranging from structural analysis to costing and computer aided design. In advanced countries many of these applications are regularly in use and are now ac- cepted as part of the industry's way of life, but computer aided design in ar- chitecture has not so far been used to any great extent.
Computer aided design is poten- tially one of the most interesting areas
by Edwin Coulter, International Computers Ltd., UK
of recent computer developments, but to some architects probably a little frightening. Computer aided design is part of a new era in computer applica- tion-that of man-machine communica- tion. The advent of new techniques in software (the written instructions which control the operation of a com- puter) now enables a person to com- municate with a computer by means of typewriter or display units.
No longer does the computer re- quire a complete program to carry out
Computers can produce perspective drawings of complex structures. A mathematical model of, for example, the design of a suspension bridge can be fed into and retained by the memory of a computer and design engineers can instruct the system to produce, by means of a digital plotter, perspective drawings of the structure from any viewpoint. The relationship between adjoining projects, such as the approach road leading to the bridge and the bridge itself, can be shown, provided the computer is fed with the relevant information
a calculation. By virtue of a pre-pre- pared file of information, relevant to the work being carried out, an engineer or designer can use the computer as a reference library and sophisticated cal- culating machine combined.
He can ask the computer a question and get an immediate reply, or he can ask the computer to make a calculation based on that question and make his own decision on the result. In this way he can converse with the computer and use that machine to aid him in building up a design idea.
This of course may be ideal for the electronic engineer whose designs are principally based on mathematical structures, but architectural design (al- though involving mathematics) is very much a visual and intuitive art. It is therefore imperative that the architect has visual representation if he is to use a computer with any effect. This is achieved with the aid of graphical dis- play devices and special light pens.
A graphical display unit consists of a cathode ray tube which looks similar to a television screen, a control panel and sometimes a typewriter-like key- board. The associated light pen is a photo-sensitive device which, when pointed at the screen of the graphical display, detects by means of the asso- ciated computer, the exact position at which it is directed and if required can be made to leave a trace of its move- ments across the screen like a pencil on paper.
The light pen can be used to feed graphical data into the computer-in the form of either diagrams or text. This information can be displayed on the screen as well as being stored in the computer. Standard routine pro- grams held in the computer can pro- vide the architect with more powerful facilities than does his ordinary pencil and paper.
Drawings displayed on the graphical unit can be enlarged or diminished in size, rotated about a chosen point, and expanded from a two-dimension sketch into an accurate perspective drawing,
Far East BUILDER, April 1969
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