The Open Design Alliance is hard at work trying to crack the mysteries of AutoCAD DWG 2007. In an initial report on his blog, ODA President Evan Yares shares a list of “new things found so far,” including a change in the ACIS Shape Manager, new entity types, and a new DST format for sheet sheets. “The thing that concerns me most is that the header sections in the new DWG format are, as suspected, a complete mess,” Yares writes.
In an earlier blog posting, Yares claims that “AutoCAD 2007 has broken backwards compatibility in a rather serious way” regarding a change in ARX objects.
Simply by comparing Yares’s current level of outrage with how he has responded to past changes to DWG, I would have to rate DWG 2007 as a rather modest change. But the whole discussion of how DWG has changed misses an important point.
In December I wrote an analysis of CAD file formats, as to their suitability of purpose ("AEC CAD Leaders Say Plethora of File Formats Serve a Purpose"). The vendors want their users to understand there is a fundamental difference between native file formats like AutoCAD's DWG and MicroStation's DGN, and various publishing formats designed to pass data along (including PDF, DWF, JT Open, CSF, and many many others). The vendor argument is about suitability for purpose. DWG is not meant to be a file format for sharing, it is a file format for creating and storing data inside AutoCAD. Using DWG as a data publishing format violates suitability for purpose. Some users are starting to reorganize their work practices around the difference, but others are adament about continuing to use native file formats to create, manage, and share engineering and design data. Until there is a general consensus on the use of publishing formats instead of native file formats, the ODA will continue to be (in the words of Autodesk incoming CEO Carl Bass) "the arms merchant to my enemies."
If the ODA really wants to be the champion of CAD users everywhere, it should look beyond DWG and work with all players--including Autodesk--on creating, supporting, and promoting a best-of-breed publishing format for CAD data. When that happens, and Evan Yares can retire his flame-thrower, then we will have real progress in CAD.
--RSN