AutoCAD

AutoCAD's Longest-Lived Bug? (Bug Watch Tutorial)

1 Dec, 2008 By: Steve Johnson

Partial plots, password-protected pitfalls, problems in paper space, and some sticky civil stuff.


Target Limitation (Release 12 to 2009 Update 2)
Submitted by Terry A. Priest.
Here's a real blast from the past. This bug may be even older than Release 12, but that's the oldest release I have available to test with. Real old-timers like me may remember when the idea behind the Limits command was to try to keep the drawing in check and stop anarchic entities from spilling outside the strict confines of a given rectangle. I don't know if anybody still uses limits like that, but I do know there are people who still use Limits to define a plotting area.

Over the years, those people may have come across recalcitrant drawings that refuse to plot correctly. Despite the limits being correctly aligned with the title block, Plot decides that just one corner of the drawing is going to be plotted. The same problem applies to plot previews, so at least you can see what's going to happen before you waste any trees.

What's the cause? This happens when the TARGET system variable is set to a value other than its default of 0,0,0. What makes that happen? There are various causes, including use of the Dview command. Since AutoCAD 2007, it has been possible to easily displace the target accidentally by holding down Shift and pressing the middle mouse button, resulting in a tiny transparent 3D orbit that moves TARGET around.

Workaround: You might think that you could manually set TARGET to 0,0,0, but it's a read-only variable, so you can't do that. You might think that using the PLAN command would fix it up, but it doesn't. The best way is to use the Dview command's Point option to put things back to normal. Here is the command sequence:

Dview [Enter] [Enter] Point [Enter] 0,0,0 [Enter] 0,0,1 [Enter] [Enter]

If you come across this problem often, it is probably worth making a menu macro to do this:

^C^C_.Dview;;_Point;0,0,0;0,0,1;;

Overprotective (2009 to 2009 Update 2)
Submitted by Owen Wengerd.
If you attempt to open a password-protected drawing from the recent files list, after you have entered the password, instead of the drawing being displayed as normal, a drawing preview is shown. The cursor passes under this preview and it temporarily gets in the way of your current drawing.

 

figure
A drawing preview appears when you open a password-protected drawing.

 

Workaround: Just open the drawing again and it will work correctly the second time.

Lost in (Paper) Space (2009 to 2009 Update 2)
One of the old, unfashionable, obscure but powerful commands in AutoCAD is -Attedit (note the leading hyphen). This allows you to perform all sorts of operations on attributes using a command-line interface. Many of the things you can do with -Attedit can now be done using alternative methods, but the command-based mechanism makes it suitable for use in customization. Even when used manually, its ability to perform global operations on attribute values is still highly useful. So it's unfortunate that -Attedit's global operations are partly broken in AutoCAD 2009.

To see this, open a drawing containing a few blocks with attributes in both paper and model space and enter the -Attedit command. Answer the first two prompts with 'N' to persuade the command to work in global mode, and press Enter past the prompts for block name, attribute, and value. Now enter a string to change that you know is used in some of the attribute values (such as 'A'), and a replacement string that is obviously different (such as 'ZZZ'). AutoCAD will perform the replacement on all the attributes in model space, but it will ignore all the attributes in any paper space layouts.

Workaround: None known, unless you include highly inconvenient methods such as copying and pasting layout objects to and from model space.

Sticky Stuff 4 (Civil 3D 2007 to 2009)
Submitted by Mike Partenheimer.
I don't normally cover the AutoCAD-based vertical products, but this relates to my earlier Sticky Stuff reports, and I just happened to be able to check this one out and confirm it for myself. Civil 3D drawings containing survey points become unbearably sticky if the dynamic UCS feature is turned on, which it is by default.

 

Workaround: Turn it off using the status line toggle or by setting the UCSDETECT system variable to 0.

 


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