Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. PLY is a computer file format known as the Polygon File Format or the Stanford Triangle Format. The Digital Michelangelo Project at Stanford University used the PLY format for an extremely high resolution 3D scan of the Michelangelo "David" sculpture. The format was principally designed to store three dimensional data from 3D scanners. It supports a relatively simple description of a single object as a list of nominally flat polygons. A variety of properties can be stored including: color and transparency, surface normals, texture coordinates and data confidence values. The format permits one to have different properties for the front and back of a polygon. There are two versions of the file format, one in ASCII, the other in binary.