Computer-aided design and manufacturing (CAD and CAM) have significantly replaced the traditional production design and manufacturing. To substantially shorten the time for developing patterns, moulds, and prototypes, many manufacturing enterprises around the world have started to use rapid prototyping methods for complex pattern making and component prototyping. These technologies are capable of directly generating physical objects from CAD databases. They have a common important feature: the prototype part is produced by adding materials rather than removing materials. This simplifies the three dimensional (3D) part producing processes by minimal wastage of material to 2D layer adding processes such that a part can be produced directly from its computer model.