Abstract

In a compression system, three-dimensional geometry is first represented as a generalized triangle mesh, a data structure that allows each instance of a vertex in a linear stream to specify an average of two triangles. Individual positions, colors, and normals are quantized, preferably quantizing normals using a novel translation to non-rectilinear representation. A variable length compression is applied to individual positions, colors, and normals. The quantized values are then delta-compression encoded between neighbors, followed by a modified Huffman compression for positions and colors. A table-based approach is used for normals. Decompression reverses this process. The decompressed stream of triangle data may then be passed to a traditional rendering pipeline, where it is processed in full floating point accuracy.

Other References

• J. W. Durkin and J. F. Hughes, Nonpolygonal Isosurface Rendering for Large Volume Datasets, 1070-2385/94 1994 IEEE
• J. F. Danskin, Ph.D. Compressing the X Graphics Protocol, Nov. 1994, Dissertiation, Princeton University, Dept. of Computer Science, Princeton, New Jerse