The work on surface and mesh compression, which began as a way of representing molecular surfaces for efficient interaction with our visualization tools, has blossomed and generalized to other applications in computer graphics and web design. One of the significant advances is methods to compress surfaces as ASCII files. Geometry compression for VRML has been an important item on the wish-list of the Web3D Consortium since 1996, but people have not wanted to abandon the portability and ease of an ASCII text-based format to incorporate the binary files that would be needed to allow compressed geometry. This is probably the reason that there is still no geometry compression in VRML. We demonstrate a mesh compression technique that produces ASCII text output, so that compressed geometry can be easily incorporated in text-based scene-description files. When compressed by standard gzip, it achieves bit-rates that rival those of a binary bench-mark coder. The decoder is relatively easy to add to software, as they demonstrate by a small (6K) Java program that plugs into Shout3D. Online demos and encoding/decoding tools are available at http://www.cs.unc.edu/~isenburg/research/asciicoder/.

Even if a binary standard for VRML (or X3D) would be accepted, it could co-exist with a text-based standard to allow complete conformance between binary and ASCII versions. Translating back and forth between the two versions would not require compression or decompression. The same decompression algorithm would inflate a compressed geometry node, no matter if it was stored in an ASCII VRML file or in a binary VRML file. There should eventually be a binary version of VRML, because it would reduce parse time and allow more compact storage, but ASCII coding allows geometry compression now, without waiting for the binary specification.