Toposolid from imported CAD (basic) - Revit Tutorial

In the last few videos, we created some really simple toposolid elements that were based off a sketch. So here's one example where we just simply sketched a simple form and then using tools like Add Point and Modify Sub-Elements, we were able to go in and manipulate some points along the surface to begin sculpting the form to the desired shape. Now that approach is effective and gives you a result something like this, but if you have more than just a few points, that's going to become a very tedious process. So if your topography needs are very simple, you might be able to get away with that. But in a typical project, it is not uncommon to have hundreds, if not thousands of points on your topography. So doing it manually is not gonna be the best approach. So what I'd like to do in this video is show you an alternative that uses imported CAD files. So I'm gonna select this topography and delete it. And then I'm going to come over here to the project browser and double-click the site plan view. And I wanna start with a CAD file instead. So most civil engineers or surveyors are working in AutoCAD or similar programs, and they can provide you a CAD file that has the contour information in it. And then Revit's able to use that information directly to create toposolids. So let's go to the Insert tab to get started. And we're gonna use the Link CAD tool as the first step here. So when you click that, that takes you out to a window that browses to your hard drive. And here in the exercise files folder, I have a file called simple contours. There's a few other DWGs in there that we're gonna use a little bit later. But for now, let's start with that first one called simple contours. So you can see from the preview over on the right, it's a very simple file, but suitable for getting the basic process down. Before we click open, let's consider the options at the bottom of the screen here. There are several of them. Now, some of these are a matter of personal preference, such as what do you wanna do with the colors? You can keep the colors as they are in the CAD file, you can invert them, you can force them all to black and white. Depending on whether you're using a white background or a dark background in Revit, you can choose whichever setting is appropriate for you there. So I'll let you decide on your own which option to choose. I'm gonna go with preserve for this example. As far as layers go, CAD files are organized into layers, and I recommend you just simply choose all the layers, okay? That way you'll get everything and you can decide which ones you wanna work with later in Revit. Likewise, with the units, I recommend auto-detect. Revit will do a good job of reading the units that the file was created in and bring it in appropriately. If for some reason that doesn't work correctly, you can always choose a different unit later. Next, as far as positioning goes, unless you know for sure that you need to use a different unit, then I think Origin-to-Origin is a pretty safe bet. That's what we're gonna use in this case, but there are other options here. Talk it over with your engineer or your surveyor to make sure. Likewise, with the placement level, in my case, it's simply gonna place it at level one, but if you have other levels in your project, then you might have more choices there. Now, we're not really concerned with oriented view for this example, so that leaves us with just two additional options. The first is over here on the left called current view only. Absolutely wanna make sure that that is unchecked if you're planning to use this imported CAD file to create topography. If you check that, it will flatten all of the 3D information down to a 2D file, and you won't be able to use that height information to create solid topography. So make sure that's unchecked. Likewise, we've got this option, correct lines that are slightly off axis. You wanna also make sure that is unchecked. And this is because there are frequently lines at different angles within the CAD file, which are deliberate. We don't want Revit to mistakenly think that those need to be corrected and forced to horizontal or vertical. So make sure you uncheck both of those boxes before you click open right here. Now you can see that this file came in quite nicely right in the middle of the screen. That won't always be the case. So in your projects, if you bring in a CAD file and it doesn't appear, you wanna make sure you do zoom to extents and check it might be off screen somewhere, you might have to zoom to locate it. Also make sure you check it in 3D. So if I click back here to the 3D, what you're gonna see is down here at the ground level for level one, we have the outline of the file, but notice that something is going on above that. And if I right click here and do zoom to fit, you can see that floating way up here is several other pieces of line work. Those are on different layers. So if I go back to the site floor plan and zoom in just a little, you can see that up near the top, I have a contour line at 780 and down at the bottom in the corner, I have one at 774. So those are the contour lines that we wanna create the topography from. So what we need to do now is figure out what layers those are. So you can do that by selecting this file, go to this query button right here, and then you can just simply touch the individual lines inside the file. So the green one, the 780 one is a layer called major. And then if I click any of these pink ones, you can see that that is a layer called minor. So those are the two layers that I'm most interested in to create this topography from. So let's click the modify tool to cancel out of there. And I will now create the topo element from those two layers. To do that, we simply go to the massing insight tab, click the dropdown on the topo solid tool, and notice that there's an option here to create it from an import, okay? So I'm going to click that, and this gives us two additional options, create from CAD or create from CSV. Now, I don't have a CSV example for you, but if you get something like that from your civil engineer, this would be a text file that contains a bunch of points in it, the descriptions of points. You can actually create Topo from that. But I'm going to do create from CAD because that's what we have. So I'll click that button, and then you just simply click anywhere on the CAD file to select it, and that will display a list of all the layers. Now, this is where we wanna do check none, and come back and check only those two layers that we just queried a moment ago. So this is why we did that step, so that we would know which ones to select here. So now I'll click OK, and that will create the toposolid. However, we don't really see it here in this site plan view. So in order to see the result, let's go back to 3D. And the thing that we need to remember is those contour lines are way up at the height of 780. Okay, they're not down here at zero where the level is. Therefore the toposolid got created up at that location. Now, the other thing that you'll notice is the toposolid got created in kind of a strange shape. So I did this on purpose because I wanted you to be aware of how this behaves. So it's looking at not only the height of the line work, but it's also looking at the extents of that line work and creating the topography to match those extents. Now it is possible to click Edit Sketch here, and here's your next gotcha. When I do that, it looks like it disappeared. So what's going on here? Well, even though the height of the contours was up at 780, notice that the sketch is still down here at zero. So just another little thing to be aware of, okay? I'm going to take this little diagonal line here and delete it, and then I'm gonna use trim and extend to a corner and just square off that corner. Now, I'm figuring that that should take care of that problem right there, and I'll click finish. However, when you go back to the result here, Notice what ended up happening. So the height of that corner where we extended isn't correct. So it actually put an unnatural slope there, kind of a chamfer down along the side. Now it's certainly possible to select this, go to modify sub elements, grab this point and pull it up to the correct location. But you could see where you're having to do a lot of manual manipulation and that's not really the desirable outcome here. The idea is we wanna use the CAD file directly to be able to create the shape that we're looking for. So what I'm gonna do is actually delete this solid, select this CAD file, go back to query and select this right here. It turns out that this file also has this layer called topo feature, and that is just the layer we need to be able to correct this problem because it is following the outline in three dimensions. So if we go back to Massing and Sight, create from import, create from CAD, select our CAD file, let's check none, select the two topo layers again, but also the topo feature and click OK. Now we're gonna get a much nicer result, which is more what I was expecting in the first place. So it's just something I wanted you to be aware of. You can choose just the layers you want, but you have to choose very carefully. And if the CAD file coming in doesn't give you exactly the layers you need to get the shape that's desirable, then you might need to do some manual rework to fix things. Now in the next video, I'm gonna show you another example where the file is a little bit more complicated and you can kind of see what I mean by that. But this video's main intention was to just give you a sense of what the overall workflow was of using an imported CAD file to generate topo solids. So in that next video, we're gonna look at a more complicated and potentially more real-world example and some of the issues that might arise in that case.