What Is the Difference Between Attach and Overlay in AutoCAD?

What Is the Difference Between Attach and Overlay in AutoCAD?

When working with AutoCAD, you may come across two common commands – Attach and Overlay. These commands are used to incorporate external references into your current drawing.

While they serve a similar purpose, there are key differences between the two. In this article, we will explore these differences and help you understand when to use each command.

The Attach Command

The Attach command is used to bring in external reference files into your drawing. An external reference (xref) is a separate drawing file that can be linked to your current drawing. This allows you to combine multiple drawings or collaborate with others by referencing their work.

To attach an external reference using the Attach command, follow these steps:

  • Select the Insert tab from the Ribbon menu.
  • Click on the Attach button in the Reference panel.
  • Browse and select the desired drawing file (.dwg).
  • Specify the insertion point and scale of the xref.
  • Choose any additional options as per your requirements.
  • Click OK to attach the xref to your drawing.

Note: When you attach an xref using the Attach command, any changes made to the referenced file will not be automatically updated in your current drawing. You need to manually reattach or reload the xref if you want to see those changes reflected.

The Overlay Command

The Overlay command is similar to Attach but comes with one crucial difference – it allows you to overlay multiple drawings without creating a link between them. When you overlay an external reference, the referenced drawing is essentially merged into your current drawing, making it a part of it.

Here’s how you can use the Overlay command:

  • Go to the Insert tab in the Ribbon menu.
  • Select Overlay from the Attach Options dialog box.
  • Click OK to overlay the xref onto your current drawing.

Note: Unlike Attach, when you use Overlay to bring in external references, any changes made to the referenced file will automatically update in your current drawing. This makes Overlay a useful tool when collaborating with others or when you need to work with multiple drawings simultaneously.

Conclusion

In summary, both Attach and Overlay are commands used in AutoCAD to incorporate external references into your drawings. While Attach creates a link between your current drawing and the referenced file, Overlay merges the referenced file into your current drawing.

The choice between these commands depends on whether you want changes in the referenced file to automatically update or not. Use Attach when you want static references, and use Overlay when you want dynamic references that reflect any changes made to the external files.

By understanding these differences, you can make informed decisions on which command to use based on your specific requirements. Incorporating external references efficiently can greatly enhance your workflow and collaboration capabilities within AutoCAD.