1. Computer Graphics Communication “Digital Documentation using 3D- CAD data and Web-3D” Tatsuya Mochizuki Shizuoka University of Art and Culture, Hamamatsu, Shizuoka, JAPAN, 430-8533, motizuki@suac.ac.jp

2. introduction introduction It is not easy to describe movements such as the assembly of a unit and the operation of machines using still images Fig. 1 Fig. 2

3. 3D-CAD and web-3D Figure 3 shows an assembly model. This assembly consists of 80 parts. The data file size for the assembly is 17MB in the original 3D-CAD file, 9MB in the ACIS format, 19MB in the IGES format, and 13MB in the STEP format. It is difficult in practice to transmit and receive files of this size via a computer network or to view them over the Internet. Therefore, we compressed the 3D-CAD data into Web-3D format, and the size became 0.3MB. Figure 4 shows the compressed data. Fig.3 3D-CAD Fig4 Web-3D

4. Animation of Web3D In the design of a physical distribution system shown in Fig. 5, the movement of “things” with time is an important element. If the design is expressed only using drawings, it is difficult to correctly understand how things move over time. Fig. 5

5. Contents of Web 3D the movement of “things” with time is defined through animation, while the assembly, which was converted into Web-3D format, is being operated. Fig. 6 Fig. 7 Web-3D to mold design Web-3D to parts assemble

6. Documentation using Web-3D In this study, by compressing 3D-CAD data so that the data can be viewed over the Internet, and by presenting animation depending on objectives, a document which is easy for users to understand can be created. These digital contents which were programmed using HTML can be viewed over the Internet using an Internet browser. Fig. 8

7. Examples of e-learning This digital documentation was created in an e-learning format.

8. Conclusion we used the shape and assembly data of a mechanical device designed using 3D-CAD to create digital documentation and manuals which are easy to understand and which are helpful to assembly operators and users of the mechanical device. In concrete terms, 3D-CAD data (assembly and parts data) are compressed and converted into Web-3D format so that they can be browsed over the Internet. Then, the assembly operation is presented by animation using Web-3D, through which the mechanism of operation is described. In addition, by creating a program using HTML for browsing the data in Web-3D format using an Internet browser, both transmission of the digital document to remote areas and documentation in multiple languages are simultaneously achieved. Finally, we confirm the usefulness of the digital documentation method proposed here, using actual examples.