Rapid Prototyping takes virtual designs from CAD or 3D modeling software, transforms them into virtual cross-sections. Then the rapid prototyping or 3D printing machine reads in data from a CAD drawing and lays down successive layers of plastic material, building up the 3D-prototype from a series of cross sections. These layers, which correspond to the virtual cross-section from the CAD model, are glued together or fused (often using a laser or UV light) automatically to create the final shape.