Evan on Engineering Software

Autodesk has updated the DWG format in AutoCAD 2007, to support the new features in the product.

Here are some of the new things that we've found:

• It uses a new 21200 version of Shape Manager (ACIS) SAT data in the dxf files.
• Lots of new header variables
• Solids now have a history attached to them, which translates to a set of supporting history objects in the dxf file.
• There are a few new entity types (helix, surface, section, etc.).
• Some new lighting classes.
• New DST format for sheet sets.
• Some minor new mtext features.

Most of these things are straightforward.  The new SAT version would be only a minor problem, if it weren't for Autodesk creating their own version of ACIS.  I'd asked them, when they first split with Spatial, if they were planning to continue Spatial's policy of publishing the SAT format specification, and didn't really get an answer.  I don't personally know if they have done this -- but the good thing is that we have some great developers, and many of the top translator developers in the industry are Open Design Alliance members, so we'll get this worked out one way or another.

The thing that concerns me most is that the header sections in the new DWG format are,
as suspected, a complete mess.   All I can say at this point is, stay tuned.  We're working on it.