Computer-aided design (CAD) is a process that allows computer users to design a variety of products and geometric shapes on-screen, rather than building them by hand. Using CAD software, one can create and modify an object to determine how it will appear and function after it is built. CAD drawings often include a computer-generated image of the design, as well as its dimensions, processes, and materials. These drawings may be either two dimensional (2D) or three-dimensional (3D). When an object is drawn in 3D using CAD, the process is often referred to as rendering or modeling, while 2D design is often called “drafting.”
CAD drawings are used in a large number number of industrial and manufacturing applications. This technology is widely utilized in art and graphic design, and gives these artists a greater level of design flexibility than that of other mediums. These drawings are also used in automotive and aerospace design, as well as in the development of industrial products and equipment. Many special effects used in films and television rely on computer animation generated with CAD software. Finally, CAD drawings are a critical component of the construction and engineering trades.
Before the invention of CAD, products and building plans were drawn by hand. This was a laborious and time-intensive process that required a high number of draftsmen, as well as frequent revisions. With the introduction of CAD software, engineers and designers were able to quickly and easily generate and modify drawings. Design firms could hire fewer staff, and both design and product development cycles were greatly reduced. CAD software also allowed engineers and designers to generate their own drawings, rather than to attempt to explain them to a draftsman, resulting in more accurate design.
Though CAD drawings have been in use since the 1960s, it wasn't until the late 1980s and early 1990s that CAD software became a cost-effective option for many industries. Early versions of the software relied on 2D vector design, while modern CAD drawings include 3D modeling capabilities. Today's modeling software allows designers to not only draw an object, but to rotate it on an axis, and to see through the object's walls from the inside. This modeling capability is particularly useful in construction and engineering, allowing designers to virtually “walk-through” a structure and explore different angles.
Most CAD software is designed only for Windows or Linux operating systems. Complex CAD drawings may require advanced graphics cards and high levels of random access memory (RAM), but simpler drawings can be done on almost any basic computer. CAD software is operated using a traditional mouse, though some professional designers may supplement this operation using a digital pen or drawing tablet.