Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member
In this movie, we'll look at another very common scenario where you will import CAD data into your Revit project, and that's when you receive data from an outside civil engineer. There is no Revit civil engineering package. Therefore, most civil engineers are either using AutoCAD or MicroStation. So you are going to get the data from them in either DWG or DGN format. Now I am in a file here called CAD Topo and in this example I'm going to bring in another DWG file, but if you were bringing in a DGN, the process would be virtually the same.
So I am going to go to the Insert tab, and click on the Link CAD button. So this time I am going to select AutoCAD Siteplan, it's a DWG file, and it's actually one of the sample files that ships with AutoCAD. It just contains some 3D lines representing the contour lines of the project. Now I am not going to change most of the settings down at the bottom, I am going to leave them the way they were set in the previous import that we did in the last movie, but I am going to make sure that I'm using Origin to Origin here for the positioning. That's usually pretty important when you are bringing in a civil file because they've probably associated with a particular origin.
And over here, it's very important that I uncheck current view only. The way to think about current view only, in the last movie we used that in order to force it to only display in one view, and that's helpful to prevent it from displaying elsewhere, but in this case, I want to actually take the CAD file, and turn it into 3D geometry, and I can only do that if that's unchecked. So in other words, it has to be visible in all views. Revit has to think of this CAD file as a model, and so we tell it it's a model by unchecking current view only.
So I am going to go ahead and click Open. When the file comes in, it's a little bit larger than the file that we had before or the setup in this file. So I am going to type Z F for Zoom to Fit and it will zoom out and you can see that I have this site plan here, and the box around it just simply highlights and shows me that it's a CAD file. Now if we take a look at this file in 3D, I'm going to click the small little birdhouse icon over here to generate my default 3D view, and then I'm going to hold my Shift key down, and start orbiting with the wheel mouse.
You can see that this file has some height to it, particularly when I look at it from edge on, and you could see that those contour lines are set at heights above the ground. So you probably want to spend the first few moments just sort of investigating the file and kind of understanding what's here. Now I am going to return to the Site Plan view, double-click that on the Project Browser here. And in this area right here, it's pretty clean, so I am going to do a zoom in region, like so.
And before I turn this into a topo surface or a topography surface here in Revit, I need to know a little bit more about this file. When you select it, the entire thing will highlight because it's a single continuous CAD file at this stage. Up here on the ribbon, we have a Query button, and I can click that button. What this will allow me to do is to reach in and touch the individual line work inside the CAD file. So you see how I can come in here, and pick any one of these individual lines.
What I want to know is what layer that line work is on. So I am going to make a note of this layer CF-DEP_INDX and make a note of this layer CF-DEP_INT. Those two layers are the contour lines that are used in this file. The rest of the geometry that's here, these lines and all this other stuff, I don't care about any of that, I don't want to generate topography from that. So that's the information I need to know. I am going to click the Modify tool to cancel the query, and I'm ready to move on to the next step.
Now the next step is to take this CAD file and use it to generate a three-dimensional topographic surface right here in Revit. I do that by going to the Massing & Site tab and I'll click on the Toposurface button. The default behavior here is the Place Point option. Place Point would require me to individually place multiple points on the screen at different elevation heights. You can see right here that you can put in your elevation height, and I would literally have to place one point at a time in order to start generating a surface.
And you can see that as you place more points, it starts connecting them together to create a surface. Now if I did that for this file, I am going to undo those four points, it would take me quite a long time because as you can see just in the small area that I'm zoomed in here, it would require quite a few points. Fortunately, right next to the Place Point, there is this Create from Import button and I can choose the Select Import Instance option, and that's going to allow me to click on the CAD file and generate the points directly from that CAD file.
Now the reason that I did the query in the previous step is because I don't want to generate points from all the layers in the CAD file, I want to click Check None, and I only want to generate them from those two layers that I queried a moment ago. So I've got those two selected, and I'm going to click OK, and it does take a few minutes for it to process, but I think you'll agree even with that short wait, it was considerably faster than it would take me to generate all those points manually. I am going to zoom in slightly right here.
Imagine how long it would take to place each and every one of those little points. So if you were doing this manually, you'd be in for a long haul. So I'm going to zoom back out. In fact, I am going to zoom to fit here, and up here on the ribbon, I am going to click Finish Surface, and that will complete the creation of this topographic surface. Now here in the site plan, you can kind of see it, it's the odd shaped thing here and this out here the rectangular border, that's the CAD file. So here is the topo, here is the CAD file.
Let's go to 3D and I'm going to do two things here to make this a little easier to see; I am going to select the CAD file first in 3D, it's actually got a box around it instead of a rectangle, and I'll select it, and I can temporarily hide the selected object. I do that down here on the View Control bar with this little sunglasses icon, I am going to click that and choose Hide Element. When you go in to Hide mode, you'll get a message up here Temporary Hide/Isolate. That lets you know that something is temporarily hidden.
You use this just whenever you want to get something out of the way. Okay, that's distracting right now. Let me get it out of the way so I can get a better look at what I'm working on. Over here, also on the View Control bar, we have our Visual Style pop-up and it's this little white cube, and white cube is Hidden Line. I want to switch to Shaded mode, and then that will shade this topo surface here in a color, and now if I orbit around, it's a little easier to understand what we've created. Now the effect is somewhat subtle across the expanse, but this is rather a large site plan, but if we zoom in a little bit, you can sort of see that it's created this three-dimensional surface that matches the contour lines in that CAD file.
So if you get data from a civil engineer in either DWG or DGN format, it's pretty easy to link it in as a CAD file, query the layers to figure out what layers contain the contours, and then use those contours to generate a topographic surface, and then use that surface as the basis for the ground plane to build your building.
Get unlimited access to all courses for just $25/month.Become a member
109 Video lessons · 9550 Viewers
102 Video lessons · 7205 Viewers
56 Video lessons · 14227 Viewers
97 Video lessons · 9529 Viewers
Access exercise files from a button right under the course name.
Search within course videos and transcripts, and jump right to the results.
Remove icons showing you already watched videos if you want to start over.
Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.
Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.