In order to create a 3D model or prototype, a special printer that is capable of printing 3D objects must be used. Sending 2D images to a 3D prototype printer won’t work, so computer-aided design (CAD) must be used.
CAD is simpler than it may sound. It simply means using a computer system to help create, analyze and modify the design for a 3D object. In other words, CAD enables you to technically draw your object on the computer in a way that 3D prototype printers can read and create. The files are usually formatted to communicate directly with 3D printers, and the software either uses raster graphics or vector-based graphics to create an image of the object’s overall appearance.
In addition to the overall look of the object, CAD files also contain information as to the processes that will be used to create the final model, the materials to be used, tolerances and dimensions. Also, while normal computer programs may not be able to design 3D objects, CAD is more complex, and can be used to design both 3D and 2D models.