Formats on ManuSoft

Missing Language Pack DWG File Repair

Thu, 22 Jul 2010 00:11:46 +0000

I wrote before about corrupt text causing bogus “Missing Language Pack” warnings in AutoCAD. That case prompted me to write a file repair utility. However, since the case appeared to be isolated, I never released the utility to the public.

The problem has been rearing its ugly head again, so I decided to dust off the original code and release it. The repair utility is now available on the freebies page (look for CleanLanguage.zip) for AutoCAD 2007 and later versions of AutoCAD. I have not tested any recent cases, so I can’t be sure it is the same problem. If you try the utility, please report your results by leaving a comment here.

AutoCAD Missing Language Pack Drawing File Corruption

Mon, 03 Aug 2009 13:38:00 +0000

I’ve been chasing a drawing corruption problem on behalf of a customer. The problem manifests itself by causing a “Missing Language Pack” dialog to display when the drawing is opened (but only in Windows XP with no language packs installed – my Vista installation apparently has all the language packs installed). Installing the language packs “fixes” the problem, in that the drawing files open without error.

However, the real problem is that some drawing objects were corrupted in memory, and corrupt data was subsequently written to the .dwg file. My customer thinks the corruption might be linked to a virus that they were infected with (and have since eliminated). I have a copy of the virus for testing, but I have not been able to catch it in the act of corrupting an open drawing file. Therefore, I cannot conclusively link the virus with the corruption.

So, I need your help. Have you recently noticed a “Missing Language Pack” dialog appearing in drawing files that have opened fine in the past? Has your virus scanner recently detected an AutoCAD related virus? If you have, please send me an email describing your situation and AutoCAD versions involved. I would like to determine conclusively whether the virus is causing drawing file corruption, and if so, whether the corruption is always in the same location of the drawing file.

[Update: Autodesk has released a technical document with information about the virus. See also Shaan Hurley’s blog post.]

Digital Signatures

Mon, 10 Dec 2007 00:00:00 +0000

Introduction

The information on this page was compiled from a series of posts on my blog in December, 2007 about the use of digital signatures in the CAD industry. Note that some information and links that were current as of the original writing may now be out of date.

DWFx: The Emperor's New Clothes?

Thu, 01 Mar 2007 19:10:00 +0000

I pointed out in a previous post that while the press release headlines pronounced that Vista will support DWF natively, the fine print says otherwise. What Vista does support natively is Microsoft’s new XPS (XML Paper Specification) format. Autodesk has since clarified that they are working on a new DWF format called DWFx that is, essentially, a DWF in XPS format.

A quick test verified my suspicions that XPS files produced by the Microsoft XPS Document Writer are much larger than comparable DWF files. The jury is still out on DWFx file sizes, but a recent post on Scott Sheppard’s blog (http://dwf.blogs.com:80/beyond_the_paper/2007/02/autocad_2008_dw.html) has buried within it a telling comparison point between DWF and DWFx.

The chart uses a neat gambit by comparing both DWF and DWFx file sizes to the completely different DWG format, but the math cognoscenti among you will notice that “typically 1/20 the size of the DWG” for DWF and “typically 1/10 the size of the DWG” for DWFx translates into “DWFx files are twice as large as DWF”. There is no information on file generation times, another metric worth monitoring.

Autodesk has been pretty generous lately, first giving away Design Review, now perhaps gearing up for an exclusive two-for-the-price-of-one deal on DWFx. I haven’t heard too many customers requesting larger file sizes, though.

Does Vista really open DWF files?

Tue, 05 Dec 2006 05:12:00 +0000

Not according to the press release. Vista (and .NET 3.0) includes a built-in XPS Viewer (also available for Windows XP SP2 and Windows Server 2003), which will view any XPS format file. Apparently Autodesk plans to add support for output to XPS format in the future, and this output will be called DWFx – a new file format. It’s not clear what the difference will be between DWFx and the output produced using the Microsoft XPS Document Writer that is already available.

I installed the Microsoft XPS Document Writer and XPS Viewer on my Windows XP SP2 machine. Next, I started AutoCAD 2007 and opened “3D House.dwg” from the Sample folder. I then plotted this file to DWF, PDF, and XPS, with the following results:

Plotter	Plot Time	File Size
DWF6 ePlot.pc3	7 seconds	139 kb
DWG To PDF.pc3	5 seconds	165 kb
Microsoft XPS Document Writer	34 seconds	829 kb

I’m not suggesting that these files all contain the same content, I’m merely suggesting that DWFx/XPS may have some undesirable tradeoffs in practice.

This whole issue about “native Vista support for DWF” may be nothing but smoke and mirrors. There is no guarantee that publishing CAD data in the XPS format will be efficient. So what will happen if users can choose between a compact DWF, a slightly less compact but ubiquitous PDF, or a very space-hungry DWFx? Time will tell, but I think this issue of DWF in Vista is getting way to much spin and not enough critical analysis.