About Opening Drawings

You open drawings to work on them just as you do with other applications. In addition, you can choose from several alternative methods.

TrustedDWG™ Drawing Files

DWG, DWT, and DWS files created with Autodesk applications and RealDWG™-based applications are trusted by Autodesk. When you open a TrustedDWG file, the following icon displays in the status bar.

If the DWGCHECK system variable is set to On (1), an alert box is displayed if
  • The drawing file format is AutoCAD Release 14 or later and
  • The drawing file was not originally created by an Autodesk application or RealDWG-based application.

For more information about TrustedDWG, click the TrustedDWG icon.

Change the Default Drawing Folder

Each time you start the product, the last folder used, for opening or saving a file, is the default path in the standard file selection dialog box.

You can specify your own default folder.

Resolve Missing References

When you open a drawing, you are notified when a reference cannot be located. From the References - Unresolved Reference Files task dialog box, click Update the Location of the Referenced Files to open the External References palette to make changes to missing external references.

The following table outlines some of the references that might be missing and describes how to handle them.

Missing Reference Types Description
External references

Missing external references are the result of to product not being able to resolve the last known location of an xref, raster image, or underlay. To resolve a missing external reference, locate the file and update its location using the External References palette.

For information about resolving missing referenced files, see

  • Resolve Missing External References
  • Attach Raster Image Files
  • Attach Files as Underlays

Missing shape files are often the result of custom shapes being used in a linetype. Browse to the missing linetype file, or place the shape file in the folder with the drawing or one of the support paths defined in the Options dialog box.

For information about custom shape files in linetypes, see "About Shapes in Custom Linetypes".

You can use eTransmit to avoid missing files when sharing drawings with others outside of your company.

Work with Large Objects

Beginning with the AutoCAD 2010 drawing file format, drawing files can support object sizes greater than those available in previous releases. With increased object size limits you can create larger and more complex models. Using increased object size limits can result in compatibility issues with legacy AutoCAD 2007 and earlier drawing file formats.

When working with drawings that you might need to exchange with others using AutoCAD 2009-based products and earlier, set the LARGEOBJECTSUPPORT system variable to 0. This system variable setting warns you when a drawing contains large objects that cannot be opened by products predating the AutoCAD 2010 release.

Recover Defective Drawing Files

In some circumstances, it is possible that a drawing file becomes defective. This can result from hardware problems or transmission errors. If a drawing file is corrupt, you might be able to recover it.