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
Shapes

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 on Drawings During Loading (not available in AutoCAD LT)

You can work on drawings before they are fully open. This is useful when you work on large drawings and you want to begin working immediately. To take advantage of this capability, the following conditions must be satisfied.

  • The drawing must have been saved in paper space.
  • The OPENPARTIAL system variable must be set to 1.
  • The INDEXCTL system variable must be set to a non-zero value.

When these conditions are met, you can create or modify visible objects, pan or zoom, turn off or freeze layers, and any other operation that does not require displaying objects not visible when the drawing was last saved.

Note: The Quick View feature will not be fully functional during loading under these conditions.

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.