The recent popularity of digital media such as CD-ROM and the Internet has prompted exploration of techniques for embedding data, either visibly or invisibly, into text, image, and audio objects. Applications of such data embedding include copyright identification, theft deterrence, and inventory. This paper discusses techniques for embedding data into 3D models. Given objects consisting of points, lines, (connected) polygons, or curved surfaces, the algorithms described in this paper produce polygonal models with data embedded into either their vertex coordinates, their vertex topology (connectivity), or both. A description of the background and requirements is followed by a discussion of where, and by what fundamental methods, data can be embedded into 3D polygonal models. The paper then presents several data-embedding algorithms, with examples, based on these fundamental methods.