Category Archives: AutoCAD 2000

AutoCAD’s magic vanishing attachments

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There are now quite a few file types that you can attach to an AutoCAD drawing as a reference, in the same way that you can attach other drawings as xrefs. We’ve been able to attach other drawings since Release 11 (1990) and images since Release 14 (1997), but every release since 2007 has introduced a new kind of attachment. In AutoCAD 2010, you can now also attach PDFs, MicroStation DGNs (v7 and v8), DWF and DWFx files.

But should you? Maybe not. It depends who is going to use those drawings after you. If you know for certain that every user of that drawing is going to be using 2010 and later, that’s no problem. But if there is the possibility of earlier releases being used, your fine-looking attachments could vanish silently in the night. Attach a PDF to your drawing in 2010, give it to a user of last year’s AutoCAD 2009 (you’ll need to save it as a 2007 DWG) and what will he see? Nothing. There is no text-screen warning, no bounding box, no piece of text indicating the file name, nothing. Just a blank space where there should be useful drawing content.

This problem isn’t new to 2010, because there are similar problems with the other recent attachment types. Let’s examine them one by one:

  • PDF – visible only in 2010 and later (except for the special case of 2009 with the Subscription-only Bonus Pack 2).
  • DWFx – visible only in 2009 and later.
  • DGN v7 – visible only in 2009 and later.
  • DGN v8 – visible only in 2008 and later.
  • DWF – visible only in 2007 and later.

It’s important to note that the attachments don’t actually disappear from the drawing. They are still stored there, even if you save to an earlier DWG format like 2000 or 2004. The attachments survive the round trip to an earlier DWG format intact; they will reappear just fine if reopened in 2010. (Round-tripping of new object types is something that Autodesk has done extremely well over the years).

In most cases, the objects are stored invisibly as proxy objects (object name ACAD_PROXY_ENTITY, known in the early days as zombies). In some cases, they are listed as special Underlay objects (e.g. DGNUnderlay, DWFUnderlay). In 2000 to 2006, they all list as proxies. How can you list these objects in earlier releases when you can’t see them? With a bit of LISP, or old tricks like LIST ALL Remove Crossing.

The moral of the story for drawing creators is to look before you leap whan attaching new object types. For drawing recipients, it’s something to carefully watch out for. If you’re the customer and you use an earlier release, you may even wish to include a don’t-use-this-attachment-type clause in your specifications.

AutoCAD 2009 – The Prequel Part 14 – What do you think?

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I’m interested in people’s perceptions of the forthcoming AutoCAD release. Based on what you’ve seen so far, how good a release do you think it will be? Please speculate using the poll on the right. If you feel the poll doesn’t give you the opportunity to adequately express yourself, feel free to add a comment here.

I intend to follow this up in a few months with a similar poll when people have had a chance to use the shipping product. It’s not scientific, but it will be interesting to see if actually using the product changes people’s opinions.

AutoCAD on Linux – Video

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Lots of people get excited at the prospect of AutoCAD running under Linux. I’m not one of those people, but for those of you that are, here’s a video from a Linux enthusiast that shows AutoCAD running in an environment that’s doing all kinds of cool geeky stuff. It’s not mine and it’s from October 2006:

YouTube Link

Cool if you like that kind of thing, that is. I think the effects would drive me mad after a short period of dorkoid enthusiasm, but of course being Linux it would all be under complete user control.

Before you get too excited, I should point out that this is AutoCAD 2000, that is, software from last century. It’s running on Ubuntu Dapper with XGL installed and it required the copying of DLLs around from a Windows installation. It’s not supported (of course), and there’s no way of seeing what the real-world drafting performance and reliability is like. It’s a cool fun exercise for somebody with far more nerdish street cred than myself, but it’s not an environment I would use to earn a living.