Autodesk lawyers have submitted a statement by Abhijit Oak on the reliability of DWG files (thanks to Owen Wengerd for posting it.) Mr Oak is Autodesk's senior director of enterprise application development, but used to be in the Q&A department analyzing error reports.
Comments on the Oak declaration:
5. Autodesk calls DWG file format "proprietary," yet the former CEO (and current chairman of the board) has called DWG the standard of the CAD world. Perhaps she can be excused for exaggerating; after all, she has on numerous occasions claimed that Autodesk software has designed everything in the world not designed by God. I hadn't realized that Mike Riddle predates the pyramids.
Mr Oak states that AutoCAD stores "user files in the DWG format, and the files will bear the file extension .dwg." True, but not uniquely. A search of filext.com shows that non-Autodesk CAD software also uses the .dwg extension:
DWG - AutoCAD Drawing Database (Autodesk, Inc.)
DWG - BravoDRAFT, Detailer
DWG - Drafix Drawing
DWG - Older Generic CADD Drawing Format
DWG - Pro/ENGINEER Drawing (PTC)
7. "Unlike when problems occur with files created using Autodesk technology, Autodesk does not have the same degree of background knowledge ... to address data integrity issues..." I'd argue that Autodesk should have NO background knowledge, because DWG files created by non-Autodesk software is none of its busines, in the positive sense.
8. This paragraph does not follow history as I know it:
"In early versions of the software, the AutoCAD program had a feature called DWGCheck." All eight releases from AutoCAD 2000 to 2007 have this feature, not just early versions. The word "had" implies that current AutoCAD no longer has the feature. "Early" implies that this feature has been around since the early days of AutoCAD, such as 20 years ago, when AutoCAD was still released with "version" numbers; AutoCAD 2000 was released eight years ago.
"In its default settings, DWGCheck feature would scan a user's drawing file..." No so: AutoCAD's documentation states that the default setting was 0, which means the feature was turned off, and thus it did not scan drawing files. Not until AutoCAD 2007 did Autodesk change the default to 1, turning on the checking feature.
"A user could change the settings for DWGCheck in order to receive an alert in a pop-up window..." This is true for AutoCAD 2004 through 2006. The declaration does not mention that DWGCheck as a second purpose as of AutoCAD 2004: to separately check for damaged drawings.
9. "...Autodesk eventually concluded that its customers were not generally aware of the DWGCheck feature." No evidence is given as to how Autodesk came to this conclusion, nor whether customers were interested in it.
11. "Entries in this database [maintained by Autodesk] confirmed circumstances where non-Autodesk files cause AutoCAD to crash..." The declaration gives two examples of IntelliCAD-generated DWG files creating a problem for a user. But the declaration presents no evidence that non-Autodesk DWG files create more problems than its own DWG files, or what proportion of problems are DWG-related -- such as if there were just two problems in 20 years.
Even if the customer had a problem opening an IntelliCAD DWG file, the problem need not be with the source of the file. For example, AutoCAD 2007 has crashed many times when I open sample drawings provided by Autodesk. The problem is not the DWG file, but whether hardware acceleration is turned on for the graphics board.
15. "Certain competitors of Autodesk participate in the RealDWG program. The ODA has not participated in Autodesk's RealDWG program." Not everyone is allowed to participate; before becoming a member, you are vetted by Autodesk. The declaration does not state whether the ODA attempted to become a member, or whether Autodesk would allow it to join; in contrast, the ODA has invited Autodesk to join its organization.
20. The declaration states that Autodesk has received no complaints about the TrustedDWG dialog box affecting batch operations -- with this proviso: "to my knowledge." This does not mean that problems don't exist, because I have received complaints about it.
Summary
Ultimately, I agree that Autodesk deserves to determine how a DWG was created. The ODA should not hinder that indentification process.
On the other hand, Autodesk should not have claimed that non-Autodesk DWG files are problematic ("Use of this file with AutoCAD software may result in stability issues"), especially now that it admits that some of its proof is anecdotal.
The new words of warning are an improvement:
The DWG file was saved by a software application that was not developed or licensed by Autodesk. Autodesk cannot guarantee the application compatibility or integrity of this file. Do you wish to continue?
This new wording becomes active with AutoCAD 2008; there is no indication whether the wording will be retrofitted onto the current release of AutoCAD.
From my post in the discussion forum at www.adskvoda.com:
"I find it interesting that the new message implies that Autodesk *does* guarantee the integrity of Autodesk-created DWG files. I suspect that the implication is unintentional, and I wonder how long the new message will last before someone spots this apparent error."
Posted by: owenwengerd | Jan 12, 2007 at 11:28 AM
Ralph, if the ODA is smart, they will hire you as an expert witness.
Posted by: Randall Newton | Jan 13, 2007 at 05:30 PM
As a matter of interest; DWG and DRG both are listed as Standard abbreviations for the word 'drawing' in the Australian Engineering Drawing Handbook. A document that precedes Autodesk and CADD in general by decades.
Posted by: R. Paul Waddington | Jan 15, 2007 at 05:52 PM
On Item 5 - DWG format is also used for all of the Intellicad versions.
Posted by: Jane | Jan 16, 2007 at 04:34 AM
Pro/ENGINEER native drawings have an extension of drw. The dwg extension is for Autodesk compatible output.
Posted by: Bob Monat | Jan 17, 2007 at 07:12 AM
It would seem to me that the very existance of hot fix patches for file-open errors, such as:
"ARX_ERROR: eDuplicateKey or ARX_ERROR: eNotThatKindOfClass
The error ARX_ERROR: eDuplicateKey can occur if you are working with a file that was saved in the 2004 or earlier DWG format from a 2007 based product. This error is caused by the presence of more recent version of AEC objects that are too complex to save back to an earlier drawing format.
Three Object Enabler Hotfixes have been released to prevent these errors."
Which are outlined in this Autodesk blog
http://autodesk.blogs.com/between_the_lines/2007/01/arx_error_edupl.html
would show that AutoCAD has a problem with DWGs from its own vertical products as well as from any outside sources. Saving a drawing in a DWG version other than the one you are working in is very common when sending files to vendors or customers, as you may be uncertain as to what release they are on even if the use AutoCAD itself.
It will be interesting if the judge can ever get to real numbers as to the failure rates of DWG files from various sources. Autodesk or VAR tech support might be the only places to have such numbers, but will that be considered too proprietary to demand as evidence?
If AutoCAD has documented fixes for its own internal cross vertical file-open errors, can the whole matter simply be thrown out of court?
Posted by: John Nolin | Jan 17, 2007 at 07:45 PM