How to optimize your AutoCAD DWG drawing files
December 2011 | Filed Under: AutoCAD Tutorials
If you’ve been following the CAD Setter Out for a while, you will know that I recommend keeping your geometry organised as you go along.
Using Polylines, Groups, Blocks, Layers and Xref’s effectively will help you to work quickly with your drawings files. Working this way will also go some way to preventing your DWG files becoming bloated or corrupt.
If you’ve been working on a file for some time, and you’ve noticed AutoCAD slowing down, then it may be worth doing a bit of a clean up to help slim that drawing file down. This could also be necessary when dealing with files from clients, suppliers or contractors.
I’ve listed a few tools and tips below that could help you put a bit of zip back into a sluggish DWG.
- Back up before you mess up!
- Go easy on explodes
- Delete unused geometry
- Find Invisible objects
- Delete unused layers
- Delete unused Layer filters
- Check your styles
- Purge Regapps
- Other issues that could be slowing your DWG down
(If you use Architectural Desktop, check out the extra tip from Mike in the comments)
As always, save a copy of your production DWG files before you mess about with them :) This is particularly important if you are working with a third party drawing.
If you receive a drawing from a third party, don’t be tempted to explode all their blocks. This can be a really bad idea. If there is more than one copy of each block in the drawing then the blocks will actually be saving memory.
If you suspect a block is causing a problem, copy it out into a blank file and exploded it. Then follow the advice below on the new file. Carefully rebuild the block and then replace or re-define the block in the original drawing.
Be really, really careful that you don’t explode a dynamic block. The dynamic properties of the block will not be able to resolve themselves and this may corrupt your DWG.
If you need to make a change to your drawing, It can be tempting to copy the old detail to one side ‘just in case’. This is all additional data that AutoCAD needs to manage. If you end up with a lot of unnecessary, old or out-dated geometry, create an archive copy of the DWG file and delete your intermediate work from your working DWG file.
Note: A quick way to delete all unnecessary objects from your drawing file is to hit CTRL+A (select all), then hold down the Shift key whilst de-selecting what you want to keep. now hit delete. Poof! All unused data will be gone ;)
There are a number of objects that could be effecting your DWG’s file size – that aren’t always visible. This could include empty text strings, points and blocks that contain only invisible attributes.
To pick up points, type ‘DDPTYPE’ at the command line to change the size and style of points in your drawing. You can now delete what you don’t need.
To find empty text strings, type ‘QTEXTMODE’ at the command, set the value to ‘1’ and perform a regen. This will replace all the text strings in your drawing with bounding boxes. You can now hunt down and delete any empty text boxes. Set qtextmode back to 0 when you are done to put your text back to normal.
Note: From 2010 AutoCAD has the option to purge empty text strings in the ‘PURGE’ dialogue – see below.
To find Block definitions that contain Invisible attributes, type ‘ATTDISP’ at the command line, and set attribute display to ‘on’. You can now select and delete any previously invisible blocks that you don’t need.
To find 3D objects with invisible faces, type ‘SPLFRAME’ at the command line, and set the value to ‘1’. This will reveal the shapes control polygon, allowing you to select and delete it.
It is possible to create an AutoCAD group with nothing in it. Fire up the ‘GROUP’ command and ‘explode’ any groups you don’t need or recognise.
Note: AutoCAD 2012 now has the option to purge empty groups – see below.
Finally, to find wipeouts that have their frames turned off type ‘TFRAMES’ at the command line and hit return. This system variable toggles wipeout frames on and off.