esign) Using high-speed desktop computers to design products. Either a mouse or graphics tablet is used for the physical drawing, and a scanner may be attached for additional input. The output of a CAD system is often electronically transmitted to a computer-aided manufacturing (CAM) system or 3D printer, which builds the objects (see CAD/CAM
and 3D printing
Generic or Specialized
CAD software is available for generic design or specialized uses, such as architectural, electrical and mechanical. The software may also be highly specialized for creating products such as printed circuits and integrated circuits.
Solid and Parametric Modeling
More complex forms of CAD are solid modeling and parametric modeling, which allows objects to be created with real-world characteristics. For example, in solid modeling, objects can be sectioned (sliced down the middle) to reveal their internal structure. In parametric modeling, objects have meaningful relationships with each other (a door must be on a wall, not the floor; holes cannot be drilled too close to the edge, etc.). See wireframe modeling
, surface modeling
, solid modeling
, parametric modeling
Two or Three Dimensions
While 2D CAD programs work for some applications, they are essentially the computer counterpart to hand-drawn objects. In contrast, 3D CAD enables objects to be drawn with sides, top and bottom so they can be manipulated as a whole and viewed from any angle.
From Rivets to Trees
Some CAD software suites can take the finished object and render it as a real-world entity. This building was designed in MicroStation Modeler and rendered in MicroStation MasterPiece from Bentley Systems. (Image courtesy of Bentley Systems, Inc. and Cooper Carry.)