Tuesday, October 17, 2006

AutoCAD in a Networked Environment

AutoCAD "Out of the Box" is not tuned to perform particularly well in a LAN/WAN environment. This tip is about ways to make AutoCAD respond faster in a networked environment.
Autodesk's Infamous Explorer Shell Extension

Since Autodesk included the ability to add digital signatures to drawings, they've also included an Explorer shell extension that allows Explorer to display signed .DWG files with a different icon than unsigned .DWG files. When Explorer lists .DWG files in a folder, it has to examine each file to determine whether or not it is signed and then display the correct icon. This takes time. On your local workstation's folders the extra time is insignificant; however on a LAN the lag is noticeable, and across the WAN the lag can be crippling. The Explore lag occurs in AutoCAD File Dialogs as well as just plain Explorer.

By default this shell extension is installed and enabled with any Autodesk product. To disable it, right-click on any .DWG file and choose "Enable/Disable Digital Signature Icons" from the menu. In the Signature Validation Options dialog uncheck the "Validate digital signatures and display special icons" check box. Click OK. Reboot.

Any AutoCAD product install or update will re-enable this shell extension, so you may get to do this more than one time. Anytime your browser access becomes slow, check this setting.

Disabling the the digital signature icon display does not invalidate a drawing's digital signature. End users are still notified on Open that they're opening a signed drawing.

Bad Printers

AutoCAD products make use of your Windows system printers. If you have a "bad" printer, AutoCAD's PLOT and OPTIONS dialogs take a long time to display as the system tries to validate the bad printer. Use Start > Printers and Faxes to ensure that all of your printers are correct, i.e. delete the invalid ones.

Bad Links

Invalid folders in Options or bad links will also cause significant slow downs as Windows tries to follow the bad links.
Sheet Set Manager

My company has come to rely heavily on the Sheet Set Manager (SSM). However, it appears to have scalability issues. This means that the more users accessing a Sheet Set Data Set (DST) at a time, the slower its overall performance becomes. So be sure to close the DST if you're not using it. Closing the SSM is not the same as closing the DST. To actually release the DST, you must right-click on the sheet set name in the SSM and select Close Sheet Set from the menu.

Sheet Set System Variables

There are some AutoCAD system variables that affect the SSM:

Saved in: User settings
Initial value: 1

Automatically opens the sheet set when a drawing associated with a sheet is opened. To prevent AutoCAD from opening a DST automatically, I recommend setting this value to 0 (zero) in a multi-user environment.

Saved in: Registry
Initial value: 2

Controls how the status data (whether sheets are opened, missing, etc.) in a sheet set is refreshed. A value of 2 causes the sheet set display to refresh based on the interval set by SSMPOLLTIME (default 60 secs). A value of 1 causes the sheet set display to refresh when the sheet set is updated. Both of these settings will generate traffic on the network. I recommend you set this to 0 (zero, Off) and refresh the display yourself as necessary. There's a tiny little button on the SSM specifically for refresh. Alternatively, you could increase the interval specified by SSMPOLLTIME and leave SSMSHEETSTATUS at the default of 2.

Tuesday, October 10, 2006


This tip deals with two nuances of the Purge command. The Purge command allows you to delete unused Blocks, Styles, Layers, Shapes and Linetypes from your drawing. (Don't worry; references in use are not removed.)

Typing PURGE at the command Line, or File > Drawing Utilities > Purge, yields the Purge dialog. From here you can choose individual items to purge or Purge All unused items at once. The default settings are to "Confirm each item to be purged" and not to "Purge nested items." In my view this is erring on the side of caution and I'd recommend reversing these two settings.

Nuance 1: What if you want to purge unused Blocks and Plot Styles but keep your unused Layers and Dimension Styles against future use? Rather than purge items one by one, use the Ctrl key to select all the items you wish to purge. You can select individual items or groups. Then use the Purge button (not the Purge All) to purge only the selected items.

Nuance 2: There's another purgeable item that's only available from the command line and must be specified separately (i.e. not as part of a Purge All). Registered applications are applications outside of the base ACAD.EXE program that are used to expand AutoCAD's core functionality. These apps sometimes become unused as the entities, settings, tables, etc. that they're responsible for are removed from the drawing. So they too should be periodically purged to help maintain your drawing's health and well being. To purge registered apps type -PURGE at the command line.

Command: -PURGE
Enter type of unused objects to purge
[Blocks/Dimstyles/.../Regapps/All]: R
Enter name(s) to purge <*>: *
Verify each name to be purged? [Yes/No] : N
Deleting registered application "RAK".
Deleting registered application "ACAUTHENVIRON".
Deleting registered application "AcDbDynamicBlockTrueName".
3 registered applications deleted.

Bonus Tip: You can list registered applications in your drawing with a simple bit of AutoLISP. Repeatedly enter (tblnext "APPID") at the command line to step through the registered applications table. Or, if you have the Express Tool DBVIEW, you can view the Registered Applications Table in a nice AutoCAD Database Viewer dialog.

Tuesday, October 03, 2006

Scale List Edit

One of my all-time favorite AutoCAD toolbars is the Viewports toolbar. This little gem lets you do all manner of Viewport operations: make Viewports, make non-rectangular Viewports, clip Viewports, and quickly set or view the Zoom Scale factor of a Viewport.

When choosing the Viewport scale you are not limited to the scales listed in the drop down. You can type in your own desired scale in the edit box. You can also edit the list of available scales with the SCALELISTEDIT command.

The Edit Scale List dialog lets you add your own scales to the list. You can move scales up and down in the list, delete entries, put your favorites first, or put those pesky metric scales at the end of the list. (Who uses metric anyway?)

Don't worry about messing up the list of scales; you can always use the Reset button to return this list to factory defaults. Changes made to this list of scales also affect the scales available in the Plot dialog.