Resolving External Reference Issues and Managing Nested Xrefs in AutoCAD Sheet Files Efficiently

Okay, let's jump in and attach this drawing to our A301 sheet file. Let's go File, Open. Find our A301 sheet file.

You might need to browse out and into your Sheets folder to find this. A301. And occasionally you will get this warning in AutoCAD.

One or more reference files could not be located or read. What do you want to do? In this case, it's telling me that the number of reference files not found is one. So let's open the External References palette to check this out.

This might have happened to you or might not have happened to you in the past. So let's take a look at all of our references and make sure they are working correctly. It looks like CAD301, A301 is the file we currently have opened.

And we have loaded the plan model, which is our roof plan. The VDCI title block, which is loaded here. And the VCEI title block, title block logo image, which is here.

It looks like in this case, AutoCAD has tried to duplicate that logo image by adding it here. Now this is the image that's found in our title block. If we replace to this path or replace this image, you'd see it update here.

And what AutoCAD is telling me in this case, is that this image is actually unreferenced. Because it's unreferenced, we don't need it in this drawing. And I'm guessing it might be in our other sheet files as well.

We can right click on it and detach. That will remove it from the drawing. But like I said, this is the only logo we care about.

And we can see that it's still here. When we do our sheet review of the other sheets, that warning will probably come up and we will do the same process to detach the unnecessary image. All right, we're now in our sheet file and we're in paper space.

Let's jump over into model space and let's attach our elevation file. So I'll go attach, attach. I'll find CAD301levmodel.dwg and hit open.

In this case, I'm going to specify the insertion point on screen because I don't want it to be on top of my roof plan. I'll hit OK. And I'm going to place it up here.

Now one thing you'll notice is that this roof plan came in with the elevation. I don't want that to happen. I don't need this geometry here.

It is a nested xref. Let's jump over into CAD301elevationmodel and look at a very specific setting and talk about how xrefs work a little bit more. And I'm going to open up my xref palette here.

And if you closed it earlier, go to insert, reference, and it's this arrow. And in this case, I want to look at the CAD301plan model. We can see that we're in the elevation model.

It's saying open. That's the file we're looking at right now. In this CAD301plan model, the type is an attachment.

We'll see that down here as well. AutoCAD offers attachments and overlays. Overlay just means that it only goes one layer deep, like inception.

If I change this to overlay, and then I'll just minimize my reference palette and CTRL S to save. When I come back into my A301 sheet file and reload this xref, you'll see my floor plan disappear. I did not have to change anything with layers or visibility.

An overlay setting means that the xref does not get continued on if that drawing gets xrefed somewhere else. In some cases, you want this to compound. You want the xref to go into another and another.

Those are nested xrefs. But if the data is only needing to be used in that drawing, like it was needed to be used to generate our elevation, we don't want to delete the xref or unload it, detach it, etc. It's okay to just set it to overlay.

And then when we attached the elevation file into our sheet file, it didn't come with the elevation. This is exactly what we need. And so now I can select my elevation and move it into the right location relative to this geometry.

Now we can turn on our xref to do this. I'm going to do it quickly with a construction line, xl enter, v enter. I'm going to use this point on the roof, and I know that this point corresponds with this point.

Now I can select my elevation drawing, m enter to move from here to the intersection here. I didn't need to align these at all. In fact, when I was placing these in the drawing, but it is helpful if you're looking at multiple xrefs in model space, if they line up based on how they work together, it can be very helpful at a quick glance.

But because we are using viewports on our paper space, these drawings could have been anywhere relative to each other. So I'm going to go back into paper space, jump into my viewport here, and I have not yet drawn a viewport at the top of this drawing. So I'm going to go to the contextual layout tab, rectangular, endpoint to endpoint.

And in this case, I'll zoom in on the sheet, then double click in and zoom in here. We want to go to the home tab, turn on my CAD301elev model no plot. There we go.

And remember, I drew this to the top of the drawing title. We can see the drawing title space in our no plot here. We're going to go to this top endpoint, z enter, w enter, shift right click endpoint, to the shift right click endpoint, check my scale, it is correct.

Now I can lock my viewport, double click out, and I'll migrate this viewport to the A no plot layer in the current drawing. Now we can hide the A no plot for the elevation model again, zoom extents, and control s to save. We now have both of our drawings in this sheet file at the right scale and with all the correct geometry shown.

All that's missing on these drawings is our keynotes. And before we move forward, let's do a quick sheet review to make sure that everything looks correct. There's one mistake in here I want us to catch.

But we might want to do this quite frequently to make sure we don't miss any other mistakes. I'm going to start with the roof plan. So I'll zoom in in paper space.