CAD

The word design, completely by itself, denotes a field of endeavor, a profession or activity. The design practitioner executes a design process. This process originates in some manifestation of what is called purpose, proceeds from there as imagination, in which forms which respond to purpose are conceptualized, and thence to a stage termed visualization, or rendering, or modeling, and finally concludes in construction or production. The last stage is not part of the design process, rather, the design process is part of it.

Computers are, in contemporary ideation, machines which compute. However, the term originates in a time before the existence of such machines, when it referred to a person who computes. Computation is the manipulation of numbers.

In the field of Computer Aided Design, the manipulation of numbers, computation, plays some role in the design process. Whether that role is limited to one sort of function or another I cannot say, but at least as an example of it the following is apparent and prominent: numbers which define an object in three dimensions are used to map that geometry onto another object which is also defined using numbers.

This kind of mapping function is our concern here.