Computer Aided Design (or Drafting), also known as CAD, is a design tool that employs computers to create drawings and models of products while they are in the process of being created. CAD was first created in the early 1960s and today is used to design almost every product on the market in the world. Many types of CAD exist for different applications, and anyone interested in how products are designed may be interested in learning more.
Two-dimensional, or 2D, CAD is used to create flat drawings of products and structures. Objects created in 2D CAD are made up of lines, circles, ovals, slots and curves. 2D CAD programs usually include a library of geometric images; the ability to create Bezier curves, splines and polylines; the ability to define hatching patterns; and the ability to provide a bill of materials generation. Among the most popular 2D CAD programs are AutoCAD, CADkey, CADDS 5, CATIA v4 and Medusa.
2.5 D CAD
In between 2D and 3D CAD is 2.5-D CAD. The models created in this type of CAD are prismatic, that is, they represent the depth of the objects. Like 2D CAD, these objects are made up of geometric objects.
Three-dimensional (3D) CAD programs come in a wide variety of types, intended for different applications and levels of detail. Overall, 3D CAD programs create a realistic model of what the design object will look like, allowing designers to solve potential problems earlier and with lower production costs. Some 3D CAD programs include Autodesk Inventor, CoCreate Solid Designer, Pro/Engineer SolidEdge, SolidWorks, Unigraphics NX and VX CAD.
3D Wireframe and Surface Modeling
CAD programs that feature 3D wireframe and surface modelling create a skeleton-like inner structure of the object being modelled. A surface is added on later. These types of CAD models are difficult to translate into other software and are therefore rarely used anymore.
Solid modelling in general is useful because the program is often able to calculate the dimensions of the object it is creating. Many subtypes of this exist. Constructive Solid Geometry (CSG) CAD uses the same basic logic as 2D CAD, that is, it uses prepared solid geometric objects to create an object. However, these types of CAD software often cannot be adjusted once they are created. Boundary Representation (Brep) solid modelling takes CSG images and links them together. Hybrid systems mix CSG and Brep to achieve desired designs.