ABSTRACT
In most CAD systems, lines are typically defined by endpoints, plus something that happens inbetween them. In architectural practice, architects make use of continuous straight or curved lines of varied thickness, colour, dotted and dashed lines, and blank lines. It is evident, however, that in many cases, particularly in the earlier stages of a design, architects are not very concerned about the exact locations of the endpoints of lines (they tend to sketch). An inherent feature of most CAD systems is that the position of lines with respect to other lines is determined solely by means of endpoints. This is somewhat restrictive in that it forces designers to make a commitment to the exact positioning of graphical elements, often before the locations of these elements has been decided within the design scheme. If the reader thinks that this is a somewhat minor criticism of current CAD software, then he should read the seminal work on sketching written by Paul Klee for his students at the Bauhaus (Klee, 1925) in which it is made abundandy clear that elements as apparendy straightforward as lines exist within analytical contexts that determine how they should be interpreted. The four main contexts that Klee develops are proportionate line and structure, dimension and balance, gravitational curves, and kinetic and chromatic energy. Although the purpose of this part of the book is to work with the objects that are provided within the kind of CAD systems that most students and designers have access to, there should be no reason to limit the rich and varied range of expressions that designers like to use in their work. It should emerge later in the book, in the context of some of the more advanced case studies, such as in Frank Gehry’s Guggenheim Museum scheme in Bilbao (chapter 28), that CAD environments are now emerging in which a greater degree of expression is possible.
