Research And Application Of CAD Drawing Metadata

CAD drawings are very important information resources in production and construction. Because of the rapid development of Internet, CAD drawings are advanced to be widely used on the Internet. It is difficult for us to search a CAD drawing among the oceanic network information resources. To solve the problem, develop and utilize network CAD drawings, it is the key to organize CAD drawings in an orderly way. It is well known that metadata is a valid way of advancing the organization and development of network information resources. And embedded metadata at a graphic file is a tendency to develop in network graphic technology. At present, there is not any document about CAD Drawing Metadata at home and abroad. It is necessary and important for us to research and use CAD Drawing Metadata.First, by analyzing the factors of CAD drawings, the structure of CAD Drawing Metadata is built. In the content structure of metadata, CAD Drawing Metadata can be divided into four types: Descriptive Metadata, Structural Metadata, Administrative Metadata and Applied Metadata. According to the principal of designing descriptive metadata, analyzing the advantages of DC metadata, CAD Drawing Descriptive Metadata is established. By analyzing the content, characteristics and utilization of CAD drawings, considering the users' demands, the basic property elements are extracted. Reusing DC 15 elements as core elements, adding few element refinements according to descriptive demands, and expanding five new elements according to the factors of CAD drawings. Defining the elements of CAD Drawing Descriptive Metadata, and stating the rules of catalogue, and markup scheme. Expressing CAD Drawing Descriptive Metadata in RDF/XML.Then, this thesis studies how to publish CAD drawings or 3D CAD models. There are two ways. One is to use binary file format, the other is to use text file format of publishing vector graphics. And it studies how to apply metadata when publishing CAD drawings or 3D CAD models.Finally, I sum up the thesis, and put forward the further studies.