Thursday, February 26, 2009

Working with XREF Files in AutoCAD



In this project you learn how to use external references to create background drawings. You'll find techniques demonstrated in this project useful whenever you use external references.

You learn how to:

  • Externally reference data from one drawing into another
  • Specify the colors used to display externally referenced drawing data
  • Modify externally referenced blocks to show the colors specified by the layers on which they reside.
By the time you complete this project you should feel comfortable externally referencing drawings for use as architectural backgrounds.
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For exclusive use of Registered User

Attaching a Drawing with Xref

In this lesson you learn how to display drawing data stored in one drawing in another using the XREF command. You also learn how to use the LAYER command to specify the colors used by the referenced data. You use the VISRETAIN command to ensure that the colors you specify appear whenever you open the drawing that contains the Xref drawing.

Prior to proceeding with this project, unpack the source files contained in the 7207a.exe or file to a folder on your local hard disk. To unpack files from a self-extracting executable, just save the .exe file to a folder on your local hard disk. From the Windows Start Menu choose Run. Select the .exe file, choose OK and specify where you want source files to be placed.

  1. Open the 7207b.dwg drawing file.
  2. From the Insert menu choose External Reference.

  3. Use the file selection tools to select 7207a.dwg.

  4. Choose Open to open the drawing.
  5. Make sure that no Specify On-Screen check boxes are selected. When these boxes are checked, you enter position, scale and rotation information after you exit the dialog box. In this case, we want the incoming drawing to be placed at 0,0 with no rotation and no change in scale.

  6. Choose OK to insert the external reference.

  7. From the Layers toolbar, choose Layer Properties Manager. You can type LAYER if you prefer.

  8. Hold down the Shift key and select all the layers that start with 7207.

  9. Select one of the color squares to the right of the 7207 layers.
  10. From the list of colors choose a light gray color.

  11. Choose OK to exit the color selection window.
  12. Choose OK to exit the layers window. Note that what all layers you attached are gray. The only exception is that the doors in the attached drawing are still displaying in yellow and red. This is because the elements of the door blocks were assigned the colors yellow and red before they were blocked. In the next lesson you learn how to make the doors obey the layer settings.

  13. At the command prompt type VISRETAIN.
  14. Type 1 to insure that the next time you open this drawing the referenced layers will display in gray.

In this lesson you learned how to attach one drawing to another, how to specify colors for referenced layers and how VISRETAIN will make sure properties you assign to referenced layers are held over each time you open a drawing.

This tutorial continues . . .