Linking AutoCAD DWG files - Revit Tutorial

- [Instructor] It's very common to get design data in formats other than Revit. Some of the most popular formats are AutoCAD DWG files or SketchUp files. If you get files in these formats, you can bring those into your Revit project and use them right alongside of your Revit geometry. So in this video, I'd like to show you how to bring in a CAD file. So we're going to bring a DWG, and we're going to bring it in as a link. So the best practice way to work with CAD data is to link it into your Revit project. And what that means is it'll maintain a connection back to the original file. So if the author of that original file makes a change and saves it, you'll be able to reload those changes and bring them into Revit very quickly and efficiently. So let's get started. I'm going to go to the Insert tab here. And you can see that on this Link panel we have lots of choices. So there's all sorts of file formats that support this functionality. We're going to focus on Link CAD for this example, but the workflow would be similar for many of the other types of files that are available. So I'll click Link CAD and then, I don't want you to double click anything in this window, I want you to single click the file called AutoCAD Floorplan because I want to talk to you about a few of the settings down at the bottom of the window, and if you double click we'll miss our chance to do that. Alright, so the first thing I want to talk about is the colors. Now of course, this is optional, there's a few different choices here. But as you can see from the preview, the walls are this bright yellow color, which might not look so good on a white background. So if you choose the Invert option for the colors that will make that color a little bit more legible on the white background in Revit. Now CAD files are organized in layers, we're going to bring them all in, the units should take care of themselves with Auto Detect. And for positioning, we're going to accept the default there of origin to origin which is going to line these two files up by their origins and I'll talk more about that in a few moments. What I want to discuss in particular is this setting right here, Current view only. Now, to put that in Revit terminology, what that means is if you check this box, it's going to treat this CAD data as view specific only, meaning that it would only show in the view that we bring it in and nowhere else. So at the moment, I'm in the Level 1 Floor Plan back here on the Project Browser, so that's the only place I would see this file. If I uncheck it, then the CAD file could show in any view as if you literally painted it on the ground with lines. Now, it's still going to be 2D CAD data, it's not going to magically turn into Revit geometry, but it'll be treated like it's part of your model, and it would show in 3D, it would show in 2D, it'll just show as flat line work. So for this example, I'm going to use Current view only. And that's going to force it to display only in the Level 1 Floor Plan and I'll show you what that looks like shortly. So let's go ahead and click Open here and you'll see the CAD file appear. Now, if you move your mouse nearby, it should highlight a box all the way around it. If yours is not doing that, and if you're not able to select it, then it could be one of two possible settings that are the cause. If you look at your Modify tool right below it there's a Select drop down. There are several check boxes here. The two possible causes of not being able to select that file are this one, Select Links, or this one, Select pinned elements. So if I uncheck either one of these, notice that I can no longer select the file. So if I reverse that still can't select it. So the only way I can select it is if both of those are checked. And that's because not only is this a link, it's a Link CAD file, but it also came in pinned. Now the reason it came in pinned is just simply because that's what Revit does when you do origin to origin. Now, the reason it's pinned is the assumption is you don't want somebody to accidentally do that. So if I unpin it, notice that I can move it anywhere I want. So I'm going to undo that, select it, repin it and now notice that I can't accidentally move it. I couldn't accidentally delete it. So if you think about this as the basis of some design data, it might be a good idea to protect it a little bit. And so having it pinned can be a pretty good thing to do. Now, the origin of the CAD file is lined up with the origin of the Revit file. And if you're interested in knowing where that is then what you can do is use this little icon down here on the view control bar called Reveal Hidden Elements. And if I click that, I get this border around the screen that puts me in this reveal mode. And you can see these little icons appear over here in the lower left hand corner of the floor plan. Now, those are not actually part of the floor plan, if I unpin this and move it out of the way, that's in Revit. So I'm going to undo that and then repin this, but that is showing you where Revit origin is and then that tells us that the origin of the CAD file was the lower left hand corner of the plan. So again, if you're curious about where the origin of that file was, it's as easy as revealing the hidden elements to see that. Okay, so now that I have this CAD file, what can I do with it? Well, there's no way to just push a button and turn it into Revit geometry. So if you wanted to use this as the basis for creating Revit geometry, you simply have to trace over it. Now it turns out that it's actually a lot easier to do that than it might first sound. So I'm going to go to the Architecture tab, click the Wall tool, and I'm just going to use generic walls for this. So I'm going to use Generic-12 inches, if you're working in the metric file use Generic-300. If you set the wall location line to Wall Centerline, which is the default. Revit does this really neat thing where it senses the presence of two parallel lines in the CAD file and then you can easily draw between those two parallel lines and quickly trace over the line work in this file. So I'm going to switch to a thinner size for the interior walls, and continue to trace over some of these. And it's usually better to try not to join up the corners. In other words, just draw a few little segments and make sure they're at the center lines, and then come back and use tools like Trim and Extend to clean it up. What you want to do is stay focused on the parallel lines and you don't want it to accidentally snap to other points. So I'll just draw a few of these, maybe zoom in just to touch here. And I will go to Modify, and I'm going to use the Trim and Extend Multiple Elements tool. So the way this tool works is you pick some element that you want to use as the boundary, and then you can extend one or more elements to that boundary. Now in that case, I did all extend but if you click an empty space that resets the tool. I can pick a new boundary and I'll extend these. But then notice that if I pick the lower half of this wall I can actually trim it. Now here, I need to close that corner up so I can use Trim and Extend to a corner, I could go back to my Trim and Extend Multiple Elements for this one here. And if you click an empty space to reset, you can even use a crossing selection to select multiple elements at the same time to extend over. Once you've added a few walls and cleaned them up, you might want to add just a couple doors just to go ahead and create some of those openings. And again, you don't need to do the entire floor plan, just enough to represent a little bit of the geometry underneath. So now I want to show you that Current view only behavior. So we've been working In Level 1 Floor Plan here, if you go to any other view this floor plan will not be visible. So for example, if I opened up the site plan view, there is the Revit geometry, but I don't see any of the CAD geometry. If I click the Default 3D View button, that creates a new 3D view and I can zoom, I can hold the shift key down and drag the wheel to orbit. And you can see all of the Revit geometry that I created but of course, you don't see the CAD file. So the idea is quite simple, this floor plan that you bring the CAD file into is a temporary working view, you do the tracing there, and then you only go back to that view if changes need to occur. Now, what happens if changes occur to the original CAD file? Well, I'm going to go back to the Insert tab, and I'll use the Manage Links button to access those changes. So in this dialog, you see all these tabs across the top, these are all the different kinds of files that we can link into a Revit project. We're going to stay focused on CAD files here. So I'm going to go to the CAD Formats tab, select the file, you want to click it by name here, it'll highlight all the way across, that activates all these buttons down on the bottom. You could remove the file, you could add another file. If the file changed in place they saved right over the original simply click Reload. If it's got a new name or a new location, click Reload From then I'll select the updated version, click Open, click OK. And you're going to see the underlying CAD file now changed. And of course, that means that some of my Revit geometry needs adjustment. So sadly, it won't automatically adjust your Revit geometry, you'll have to do that yourself. But it's really not that hard to do. It's a simple move command that would allow me to move those elements over to where they need to go. So if your workflow involves getting files in other formats, you can link those files into your Revit project and create a hybrid scenario where some of the geometry is coming from CAD or other formats and some of the geometry is in Revit. And then you can always reload those files as changes occur.