How to use xRef in AutoCAD, a complete step by step guide

External Reference in AutoCAD

AutoCAD External References (Xrefs) is a powerful feature that allows you to integrate external files seamlessly into your primary drawing, making collaboration possible within your projects.

Xref in AutoCAD offer benefits like collaboration, organization, streamlined editing, and error reduction.

In this guide, we'll walk you through everything you need to know about AutoCAD External References using a practical example with a DWG file.

You can download the lesson files used in this tutorial here.

Also, if you prefer the video then here it is, else read on.

Understanding AutoCAD External Referencing

AutoCAD External References, or Xrefs, enable you to insert various files such as DWG, images, PDFs, and point cloud data, into your drawings.

The idea of Xref is that you can have different people working on the project, each person working on a specific component which can be integrated into one component using the Xref feature.

Using Xrefs with a Drawing (DWG) file

Imagine you're working on a building project and have separate drawings for the floor layout, electrical plans, plumbing, and furniture.

Multiple people from a team can work on different parts of the project and then all these separate parts of the project can be easily integrated into a master drawing while preserving individual editability.

Before we start attaching external drawings we need to set Up the Host Drawing.

Assuming you do not have any previous drawing, you can start by creating a new drawing for the building's layout plan, designated as the "host drawing" as this will serve as the foundation for integrating external references.

In this case, open a new drawing in AutoCAD then type UN and press enter to open the unit command palette.

Change the units to meters, with a decimal place of three (3), and then save the drawing as a "Building layout plan" as shown below.

You can now Attach your External References.

You can either use the XREF or ATTACH command, to insert external references into the host drawing.

Additionally, under the insert tab, reference panel, you can find the Attach command as shown below to bring your external reference drawing into AutoCAD.

Once the command is active, the Select Reference File menu will pop up, from where you can select the file of your choice from the supported format in AutoCAD (All image files, DWF. File, MicroStation DGN. file, All DGN. files, PDF files, AutoDesk Point Cloud file, Navisworks file, and Drawing file).

If you had used the XREF command, the External Reference palate would have popped up, and under the file reference window, right-click on your mouse to activate the various attached file options mentioned above as shown in the following image.

In this case, select Attach DWG and then the Select Reference File menu will pop up.

In this case, you will be working with the Drawing file (Dwg.), select the Floor plan file as shown below and click Open.

Make sure you have Drawing (*.dwg) selected in the Files of type menu as shown in the following image else the DWG files won’t show up in the folder.

After selecting the file and clicking the open button the Attach External Reference menu will pop up.

Under the menu you can adjust your Scale, Path type, Insertion point, Reference type, etc.

For our example, make sure points 2, 4, and 5 have been left unchecked, to ensure you are working with the defaults.

For other options, leave everything as shown below, and click on OK.

Before we move further let’s explore the options in the Attach External Reference options window.

Point 1: 

The Name option is usually a drop-down list that you can use to select the appropriate DWG file that you want to import. You can change the xref attached to the list by click on browse and select by selecting a new document.

Point 2: 

The Scale option allows you to alter the scale of the DWG file that you are importing.

You can opt to input only one value by checking the Uniform Scale option; or in the event you want your drawing to have different scales for different axes, you can input the values separately.

By leaving the Specify On-screen option checked, AutoCAD will prompt you to select the scale within your workspace.

Point 3: 

The Path Type option allows you to select from three main options, No path, relative path and Full path.

No Path Option

With No path option AutoCAD does not save any path for your Xref. For this option to work, it will require your Xref document to be in the same folder with your Parent (Host) file.

Relative Path

The Relative path option specifies the location of a file relative to the current drawing file, e.g., If your drawing is in "C:\Projects\Drawings" and your referenced file is in C:\Projects\Images", the relative path might be "...\Images\filename.jpg. essentially ignoring common file path.

It makes it easier to move projects between different folders or computers without breaking the file references, as long as the relative structure (the common path) remains the same.

Full Path

The Full Path option specifies the complete directory location of a file from the root directory e.g. C:\Projects\Images\filename.jpg.

The benefit is that it always points to the exact location of the file, regardless of the location of the drawing file.

Point 4: 

The Rotation option makes it possible to rotate your Xref. You can either opt to do the rotation at this level or you can check the “Specify On-screen” option if you prefer to provide the rotation angle in the drawing workspace.

If you do not want your Xref drawing rotated, then leave the value in the option as 0.

Point 5: 

The insertion point option allows you to specify the coordinate point where your drawing will be placed within your workspace. By leaving the Specify On-screen option checked, AutoCAD will prompt you to select the point within your workspace.

Point 6: 

The Reference type option has two main options, namely Attachment and Overlay.

Attachment

Attachment is a type of Xref that remains linked to the drawing and will be included as an Xref if the drawing is referenced by another drawing.

If you attach a drawing as an attachment and then reference the current drawing into another drawing, the attached Xref will be nested and visible in the new drawing.

It is used when you want the Xref to be carried forward in any subsequent drawings that reference the current drawing.

Overlay

Overlay is a type of Xref that is linked to the drawing but does not pass through to any other drawings that reference the current drawing.

If you overlay a drawing and then reference the current drawing into another drawing, the overlaid Xref will not appear in the new drawing.

Overlay is used when you want to reference an Xref for the current drawing only and do not want it to be included in any nested references.

Point 7: 

The Block Unit option is usually read-only and it gives the information of the file being imported, plus what are the units and scale factor used in the specific block.

After clicking OK (point 8), your DGW file will be externally referenced into the new drawing that you have created and if you cannot view your drawing, simply zoom your “drawing extents” by double-clicking on your mouse wheel button.

You will realize that the attached Xref DWG looks a bit faded, it is because it is attached with 50% transparency to help distinguish it from a regular drawing object.

If you were to add other Xref files to your current drawing, AutoCAD will remember the initial settings you have specified under the "Attach External Reference" window.

Now repeat the same procedure for the plumbing and electrical plan as shown below with special care on your importing scale to be the same for all the Xref drawings.

Also select your appropriate insertion point using the available coordinates option shown in Point 5 above.

Here is how you can import all the remaining Xref drawings:

Additionally, you can run the XREF command to make the external reference palette visible to see all the details related to external references that are added to the drawing.

Using Xrefs with an Image file

AutoCAD gives you the option to attach images to your drawing document using the same steps as shown above.

Start ATTACH command and then In the Select Reference File window select an image that you want to import.

Make sure in the files of type option “All files” is selected else you won’t see any image file in the selection window.

After selecting the image click on OK.

The Attach image window will open with fewer options than attach external reference window.

The available options in this window are same as the ones found under the "Attach External Reference" window as explained above.

Select the default options as shown in the image above and then click OK to insert the image in your current drawing.

Modifying Xref files:

Now that we know how to attach external references let’s talk about modifying them as well.

To make changes to referenced files, you have two main options namely Edit Reference In-Place or Open Reference.

Using Edit Reference In-Place

To use the Edit Reference In-Place, you need to first select the specific DWG. file to activate the External Reference contextual ribbon.

Once you have selected Point 1 as shown in the image above, it will enable you to edit your Xref file with the current drawing without opening it in another tab.

This option comes in handy when you want to compare the background of what you are working on with the document you are modifying.

The document that you are modifying will be shown without any transparency, making clear which file you are working on.

After making the modifications click the “Save changes” option as shown in the following image.

Using Open Reference:

Alternatively, still within the External Reference contextual ribbon, you can find the Open Reference option as shown in the point 2 of the image above.

This will open the file in an external tab, where you can modify it and once satisfied, save the DWG.

Upon returning to the host drawing, you find a prompt stating that “An Xref was modified” and all you need to do is reload the Xref to reflect the updated changes as shown in the following image.

After reloading the file you see a revision cloud highlighting what was modified, and if you are satisfied with what was modified, click on the green tick, meaning Okay.

Clipping Xref

When you are working on Xref files and there is some information you would prefer to mask, you can use the Clip option to achieve this.

Within the External Reference contextual ribbon, select “Create clipping boundary” option highlighted by Point 3.

Once selected, AutoCAD will prompt you to choose the type of clipping boundary you prefer e.g., Rectangle, polyline, etc.

Select Rectangle and then draw the rectangular clipping boundary over the objects you want to show in your model.

Click on Enter key and the drawing file outside the selection will be masked.

If you want to invert what has been masked, simply select the clipping boundary, and click on the invert symbol on the clipping boundary as shown in the following image

If you want to delete the clipping, simply select the clipping boundary then from the External Reference contextual ribbon, select Point 4 which is “Remove Clipping” option to remove the clipping boundary.

Moreover, you can create clipping boundaries from already existing polylines within your drawing.

To do this, just draw a polyline over the area you want to clip, then select the xRef to activate the External Reference contextual ribbon, select “Create clipping boundary” option, and choose the Select polyline option from the command line, then select the specific polyline.

Finding unresolved references:

Unresolved references in AutoCAD occur when the program cannot locate the external files (Xrefs, images, fonts, etc.) linked to a drawing.

To find unresolved references, you can use the "External References" palette (accessible via the XREF command).

Unresolved references will typically be marked with a warning icon or highlighted in red and AutoCAD will prompt you with a warning as shown in the figure below.

The main causes of unresolved references may include a change in the File Location where the file path has changed or the file has been moved or deleted.

Other issues creating this unresolved xRef error include Incorrect Paths which happens when the reference path is incorrect or has been modified.

Network Issues when files are stored on a network, issues like server downtime or connectivity problems can cause references to become unresolved, or even lack of proper access permissions to the directory where the reference files are stored.

Nevertheless, you can resolve the Unresolved References by using the "External References" palette to identify missing files.

To access the External References, you can either click on the first option in the AutoCAD warning, using the XREF command.

Alternatively navigate to the Insert tab > Reference panel > More settings – by clicking on the small down-arrow, as shown below:

Then update paths by right-clicking on the unresolved reference in the "External References" palette.

Select the file that has a warning symbol, then select "Change Path," and browse to the correct location of the file.

Then ensure relative paths are used if files are moved within the project directory.

Check if the network is accessible and permissions are correctly set then, detach and then reattach the references.

Transmitting External References in AutoCAD

Files that have Xrefs cannot be exported as regular DWG files, to transmit external references (Xrefs) in AutoCAD, you should use the eTransmit command.

This tool packages the current drawing along with all associated files, including Xrefs, images, fonts, and plot configurations, into a single compressed file (ZIP or EXE).

It ensures that all necessary files are included and paths are correctly maintained when sharing the drawing with others. 

By using eTransmit, you can avoid missing references and ensure that recipients have all the necessary files to open and work with the drawing correctly, facilitating seamless collaboration and file management.

To access this option, first save your drawing then navigate to the command through AutoCAD icon > Publish >eTransmit as shown below:

Once the option is selected, the Create Transmittal window will pop-up where you can go through the available settings to save the entire document as a package.

Frequently Asked Questions: 

Finally, let’s check out some of the questions related to xRef that our readers ask quite frequently.

How to remove Xref in AutoCAD?

To remove an Xref, run the Xref command, then right-click on the file you want removed from your model.

From the options available, either use the "Detach" option, which permanently deletes the external reference from the host drawing.

You can use “Unload” option to remove the file temporarily and you can select reload option to bring back the drawing.

How to bind an xref in AutoCAD?

You can bind an xref in AutoCAD to convert the attached reference into a block.

By doing so you essentially break the link of xref file and make it part of the main drawing.

To bind the Xref type XREF and press enter key.

The external references palette will open up, from this palette select the xref and then right click on it and then select Bind from the contextual menu as shon in the following image.

In the next pop up you will get an option to select from Bind or Insert.

You can select either of these options as there is a small difference between these two but ultimately both options end up binding the xref to the main drawing.

How to explode xref in AutoCAD?

Xref can't be exploded, but you can bind the xref using the method shown above to convert it into a block in the main drawing.

After adding it you can use the explode command to explode the block and convert it into native drawing objects.

Summary

In summary, external referencing in AutoCAD is an essential feature for collaboration, organization, and efficiency in project management.

By incorporating various file formats such as DWG, images, PDFs, and point cloud data, users can seamlessly integrate different project components into a master drawing.

This guide has covered key aspects of using Xrefs, including setting up the host drawing, attaching external references, modifying Xrefs, using underlays, and transmitting external references.

The proper use of these tools ensures accurate and consistent project documentation, which is crucial for successful teamwork and project execution.

For a more comprehensive understanding and hands-on training about all features of Xref check the xRef chapter from our AutoCAD beginner’s complete course.