Linking AutoCAD DWG files - Revit Tutorial

- [Instructor] It's very common to need to access files that were created in other software when you're working in Revit. So in this video I want to show you the process of working with an AutoCAD DWG file within our Revit project. Now I'm going to go to the insert tab for this. And there's two ways that we could access a CAD file and that is either using the link mechanism or the import mechanism. Now import would embed the file directly in the Revit project with no connection to the original. So if you needed to update changes, you would need to remove the original version, delete it and then re-import from the updated one. Compared to Link where the link would be maintained back to the original file. And so you would simply refresh the link and it would capture the latest changes. Generally speaking, linking is considered the best practice. And so unless somebody tells you otherwise, you should really always default to using Link. But you can check with your CAD or BIM manager to be sure what's used in your own firm. I'm going to be demonstrating with Link CAD and that button is right here. And the first thing I want to point out in this dialogue is the file formats that are supported by this dialogue. So notice that there are several different CAD formats supported. Now I'm going to leave it set to dwg which is the AutoCAD file format. But you're welcome to explore the others on your own later if you wish. Now I'm going to select this AutoCAD Floor Plan file that I've provided with the exercise files at the top. Don't double click it, just simply single click on it. And there are three settings at the bottom of the dialogue that I want to direct your attention to. Over here on the right we have the positioning which is set to origin, to internal origin. I'm going to leave that just the way it is. In the middle we have colors which is currently set to Preserve. I'm going to leave that set just the way it is. And then finally over here on the left, we have this Current View Only checkbox. And for this example, I'm going to leave that unchecked. So let's go ahead and click open here and you'll see the file appear. On my screen, it comes in in this bright yellow color and it's just a little bit off center. So let's think about those settings that I just pointed out to you in the dialogue, starting with positioning which was origin to internal origin. I'm going to zoom in a little bit here on the CAD file for this. Down at the bottom of the screen there is this Reveal Hidden Elements icon. Go ahead and click that. And what you're going to see is these little symbols appear here in the middle of the screen. Those are indicating the Revit origin. So this is the origin of the Revit file. And then as you can see, that lined up with the origin of the AutoCAD file, which happened to be the lower left-hand corner of the Floor Plan. So when we choose origin origin, it just simply lines those two points up. And in a lot of cases, that's going to be the appropriate way to link the files in in order to get proper alignment. Now, in some cases it won't be. So if the file comes in and it's not in the right location, you can choose a different option there. But I think defaulting to origin origin is not a bad option in many cases. Now, next we had the colors and I left it set to Preserve. And as you can see, Preserve doesn't look so nice on a light theme here in Revit. If you're using Revit's dark theme, then it probably looks just fine for you. Okay, so one option is that I could go to the View tab and I could toggle my canvas theme and now it looks much better. So if you are comfortable working that way, then that will work perfectly fine. Now the other option is, is that I could remove the link and relink it and invert the colors and I'm going to show you that in just a moment. Before I do that though, I want to talk about the last thing which was the Current View Only setting. We left that unchecked. I'm going to open up a couple other views here and show you the result. Down here, under Coordination and Floor Plans there's some working Floor Plans and I've got this one called L1 Working. I'm going to double click to open that up and notice that the file displays here as well. Furthermore, if I go to the Default 3D View so the little birdhouse icon up here on the toolbar, that's going to open up the 3D View. And as you can see, the file shows here as well. I do want to stress that just because the file shows here in 3D, doesn't mean that it automatically became 3D geometry. Notice that it stayed flat and it's just a bunch of 2D linework that is sitting flat on the ground. Well, whatever the CAD file is that you bring in, it's going to come in as is, it's not going to automatically be converted to anything in Revit for you that you would have to do on your own. That's a separate process. It's really important that you understand that if you're bringing in a 2D file, you get 2D line work in Revit. If you're bringing in 3D geometry from CAD, it'll stay 3D but it's still going to be CAD 3D geometry. It won't become Revit elements like walls, doors, and windows. Now we understand those three settings. What I want to do is I'm going to go to the undo dropdown here and I'm going to back all the way up to Import Vector Data and that's going to remove the file, reverse everything. I'm going to toggle my canvas theme back again 'cause I prefer working on the light theme. And I'm going to bring the file in a second time and change a couple of those settings. So I'm going to go to insert, go to link CAD, select the Floor Plan again. I'm still going to do origin origin, nothing wrong with that but I'm going to change the colors to Invert and turn on Current View Only. Now, if you're working in the Revit dark theme, don't invert the colors, leave them set to Preserve, click open, and now you're going to see the difference, right? These colors are much easier to see on the light theme background and this is the result of having checked Current View Only. If I click over here to the Architectural Floor Plan, notice it doesn't display there, it's only displaying in my working Floor Plan here. If I go to 3D View, it's not displaying here as well. So the idea is that now the CAD file only displays in my Working View, which I'm using it as a means to an end. It's going to be an underlay, and then when I'm done, none of the other views have it visible so I don't have to worry about trying to hide it and all those other views. So that can be a good way to work if your intention for bringing the CAD file in is to use it as a basis for doing other design work which is what I want to demonstrate for you now. So let's say that my designer worked in AutoCAD and now I want to take their work and I want to start creating Revit geometry from it. Well, sadly, there's no button that's going to convert this CAD file to Revit geometry automatically. So that means I'm simply going to need to trace over this CAD file with Revit walls and doors and other elements, okay? Now I know at first that sounds a little daunting but it's actually not that bad. Let me show you. So I'm going to go to Architecture, go to the Wall Tool. Let me choose generic 12 inch wall, if you're working in Imperial, if you're working in metric, choose Generic 300 and move your mouse near one of the exterior walls here. And you might need to zoom in to see it but it will sense where the center is between the two parallel lines. And you can just click to start drawing that wall and notice that it lines up perfectly. Now, stop a little bit short of the corner which I know is a little counterintuitive. Press Escape once, so that's going to keep you in the command but break the chain. And then it's much easier to sense the center line of the next wall if you do it that way. Press Escape once. I'm going to change the wall type now from generic 12 to generic 5, zoom in even closer and I'm going to repeat that same basic process on some of these other walls. Press Escape once, right? Find the center lines. Press Escape once. You're going to ignore doorways. Okay, so doorways we're going to deal with by placing actual Revit doors. So let me just go ahead and place a few of these walls. That's enough to get the point across. Now I'm going to go to trim and extend a corner. I'll trim up this corner, I'll trim up this corner and then I'll use trim and extend multiple elements. Pick this is the boundary, extend this and this. Click an empty space to reset, click this is the boundary, click this and this empty space to reset. This is the boundary, this and this, empty space. I'll click the modify tool to enter. All right, so there's some basic walls. Let me just throw a few doors in just to kind of make it look a little bit more complete. So I'm going to go to the door here. You can just use the default size that comes up, even though it's a little bit too large, I think it gets the point across. And I'm just going to place a few of these doors in here in various locations just to kind of get the basics down here. In this Working View, it's a little bit cluttered, a little difficult to see what we've got. But notice if you switch over to the L1 Architecture, it looks perfectly fine. If you go to 3D View, hold the Shift key down and orbit, that looks perfectly fine as well. So the whole idea of working in the Working View and doing Current View Only means that you can very easily use that as the basis for building your model, but then your other views, it automatically is not displaying. Now the final thing I want you to see is the whole reason we chose Link was because we wanted to maintain the ability to be able to refresh this CAD file. So how do you do that? So let's say that the designer sent me an update. Okay, so now how would I access that update? Go to the Manage tab. You're looking for the Managed Links dialogue. I'll click that. Now there's lots of tabs in here. We're going to stay focused on CAD files. So I'm going to click over there. There is my Floor Plan right here. Down at the bottom of the screen you can see a number of buttons. I could reload this link, I could unload this link, I could add another link, remove it if I didn't need it anymore. Now, if the original owner of this file not only sent an update but they changed the name, or if somebody on your firm moved it to a different location, then instead of Reload, you can choose Reload From. That's what we're going to do here. And you can see I've got an updated version of the Floor Plan in the same folder. I'm going to choose that. I'm going to click Open, Okay and then you can see the effect of the change. Now, once again, notice that the Revit geometry has not responded to this. So you would need to make a selection of the appropriate elements that have been affected by the change and simply modify them. But you can snap to the geometry in the CAD file. So it's pretty easy for you to update your Revit geometry to match the new CAD file. So that is an example of a workflow that allows a hybrid between some folks that are working in CAD and others that are working in Revit. So if you find yourself in that scenario, then you can use some version of that workflow as your basic procedure.