An acronym for computer-aided design (sometimes also called computer-assisted design'). In graphics, CAD systems and software are special workstations and programs that aid in architectural, engineering, and scientific design by enabling a real-time link between the computer and designer-initiated input via a graphics tablet, a light pen, or a mouse. Depending on the specific CAD program, rendered objects can appear as wire-frame models, as shaded models, or as solid objects.
CAD is frequently used in conjunction with computer-aided manufacturing (collectively known as CAD/CAM), a general category that involves the use of computers in design and manufacturing. Other related acronyms include CADAM (computer-augmented design and manufacturing) and CADD (computer-aided design and drafting).
Some of the specific functions of most CAD programs include:
Wireframe modeling, in which the object is represented as simply connected points in space. Often, wireframe representations are the most expedient model forms, as they require less processing power to change and manipulate.
Layering is a means of dividing the drawing into color-coded layers, which can be turned off to reveal additional layers of the drawing.
Solids modeling involves the "filling in" of a wire-frame, and enables the designer to evaluate the physical characteristics of the object being designed, such as center of gravity, mass, etc.
User-defined view senable the designer to "rotate" the object (either figuratively or literally) so as to see it from a variety of different directions.
Auto-dimensioning allows the designer to change one particular dimension of the object while the computer will then alter all the other dimensions affected by the change.
Coordinate tracking keeps the designer apprised of where s/he is on the x, y, and z axes.