PLY, polygon file format, represents 3D file format that stores graphical objects described as a collection of polygons. The purpose of this file format was to establish a simple and easy file type that is general enough to be useful for a wide range of models. PLY file format comes as ASCII as well as binary format for compact storage and for rapid saving and loading.
U3D (Universal 3D) is a compressed file format and data structure for 3D computer graphics. It contains 3D model information such as triangle meshes, lighting, shading, motion data, lines and points with color and structure. The format was accepted as ECMA-363 standard in August 2005. 3D PDF documents support U3D objects embedding and can be viewed in Adobe Reader (version 7 and onwards).