XVL: a compact and qualified 3D representation with lattice mesh and surface for the Internet

Computer graphics systems and CAD/CAM systems are widely used and an abundance of 3D-Data in various fields exists. However, based on the VRML technique, it is difficult to send such 3D-Data through the Internet, because of the large data size. Transmission of practical and highly detailed 3D-Data through the Internet becomes a primary requirement. Therefore, a compact and qualified 3D-Data representation method is greatly required. This paper describes XVL (eXtended VRML with Lattice), a new framework for compact 3D-Data representation with high quality surface shape. By utilizing a free-form surface technique, qualified surfaces are transferred with a limited amount of data size and rendered. Free-form surfaces transferred by an efficient data structure are called lattice structure. This data structure contains only vertices, topologies, and attributes, and can be converted to the original surface. Because the lattice structure is regarded as a polygon mesh, it can be easily integrated to a VRML file. These surfaces and lattice have the same topology and are thus interchangeable in the lattice structure. By using weighting attributes, a sophisticated surface shape can be represented. Some practical XVL applications, such as an intuitive surface design system, are also introduced.