Progressive browsing of 3D models

High-speed desktop computers, capable of rendering complex 3D models, are becoming more commonplace, resulting in increasing interest in virtual reality systems. Virtual Reality Modelling Language (VRML) has become the de-facto standard for the description of virtual worlds over the Internet, yet the current version (VRML97) lacks capabilities for progressive transfer. This paper describes the implementation of a browser that allows the progressive transfer and simultaneous viewing of 3D models, stored in a progressive format on a Web server, using a codec based on MPEG-4 verification model source code. The authors then implement their own codec that is progressive per-vertex rather than per-level. This approach also has the benefit that it does not alter the vertex coordinates. Finally a watermarking scheme, based on the second codec, is proposed