Compression and storage of computer aided design data

摘要

The size of lightweight JT data files containing CAD data is reduced by employing lossy compression where acceptable for portions of the CAD data, such as 3D geometry data. Compression for the remaining portions can be augmented by exploiting common repeated structures for some portions, such as precise Brep data, and compressing separate but similar data, such as all metadata for a given part and all scene graph data, together as a single block. The compressed data is then written in separate, uniquely identified data segments indexed in a table of contents, allowing quick access to any data segment for streaming.

主权项

1. An apparatus for storage of computer aided design data, comprising:
data storage in which computer aided design data elements are selectively stored; and a controller coupled to the data storage, the controller configured to
produce compressed data from the computer aided design data elements by selectively employing lossy compression on portions of the computer aided design data elements, including grouping and compressing scene graph data of the computer aided design data elements for storage as a single block; andwrite the compressed data elements to the data storage.