Creating a segmental arch - Revit Tutorial

- [Instructor] One of the most common places to find curves in a building is arches. Arches can go above doors or windows or other kinds of openings, and they come in all sorts of shapes and sizes. So when you make an arch family in Revit, you're typically going to make a parametric so that it can conform easily to the shape of the door or the window that you're placing it above. Now we're going to look at a few different types of arches over this in the next few videos, but in this video, I'm going to focus on the segmental arch. So the segmental arch is kind of this low, shallow shape there, or sort of more eyebrow type of form. Now, I'm going to switch over here to Revit, and I've got this file open called Sandbox, and this just has a few pieces of geometry in it. And the first thing I want to talk about is the kind of family that we're going to create. We're going to create something called a face-based family. So let me demonstrate what that is. I've got one loaded in this file already so I'm going to click the component tool and the face-based family that I've got preloaded is just called cylinder, and the default placement mode in the 3D view is place on face. So what that means is that you can choose any surface anywhere in this file to place this family. So I could place it horizontally, I could place it on this sloped surface, vertically, even on these edges here would be allowed. So that's what we mean by a face-based family. So it's a hosted family, but its host is a surface and it doesn't much care what kind of surface it is. Any surface will do. In fact, you could even place this thing on the surface of another family. So it's a very flexible type of host. Alright, so I'm going to click the modify tool to cancel out of there. I'm going to minimize this file and in the background, I have another file open. This only is called FB Seed, FB for face-based. So this is another seed family, and it was created from the face-based generic model template. Now the face-based generic model template includes this extrusion right here which you can see in 3D, and it's just a simple box, and that represents the surface of your host that you're going to place your object on. So your job when you're working with a face-based template is to just simply build your geometry relative to the surface of that extrusion. That extrusion doesn't go into the project as you saw, it's just here as temporary geometry in the family editor. Now in all other ways, I've set up this seed family the same way as our other see family. So it's got a right reference plane, a left, a front, a back, it's got a couple dimensions and parameters. For the purposes of creating an arch, even though it's possible to place this on a horizontal or a sloped surface, I'm going to be focusing on those vertical surfaces of the walls. Therefore, I want to think about orienting this thing vertically. That means that this reference plane which is currently called back is probably not a great description. So I'm going to rename that to top. Likewise, this one is called center front back, and that's also probably not a great description. So there's nothing special about this name. You could rename it as well, so I'm going to call that one spring line because that's where I'm going to spring my arch from. Now this reference plane here I don't need so I'll simply delete it. Now that does leave behind this one dimension here, and I actually want to parametrize that. Now in this family seed, I've created another parameter called H for height so I'm going to label that dimension with that H parameter. Now I noted that we're going to be working with a segmental arch in this first example. So right now, the proportions of one in the height and two in the width would actually give me a Roman arch. Okay, so whenever you've got the height equal to exactly half the width, you get a half circle or a Roman arch so I'm going to take the width here, select the dimension, and then select the label, and I'll just make that a little wider. So that gives me a longer proportion, something more appropriate to a segmental arch. So now that I've kind of restructured the framework a little bit, I'm ready to actually build the geometry for my arch, and I'm going to do that with a sweep. So I'll go to the create tab, click the sweep tool, and then sketch the path. Now, I'm going to sketch the path using a start-end radius arc because that will give me the arch shape that I'm looking for. The start point is going to be right here on the left intersection, the right intersection will be the next endpoint, and then you're actually creating the radius next here, and what I want to do is snap right to the intersection of that top reference plane in the center line. Now if you follow the temporary dimension of the radius down, you can see that that places the center point of this arc below the spring line, and that's appropriate for a segmental arch. So I'm going to click that point to place it, click the modify tool to cancel out, and that gives me this single arch sketch line. Now, the next thing I need to deal with, of course, is all the automatic sketch dimensions that appear. So what I want to make sure happens is that those two endpoints stay right where I put them. So I can use align and lock for that purpose. So let's go to the align command. I'll do the left reference plane, and then highlight near the endpoint of the arc. Now we've seen this in previous videos, but we've also seen that sometimes it highlights the automatic sketch dimension. So make sure you're getting the sketch line and if you're not, just press tab until you do. See, now I'm getting the sketch line and then I can lock it. So I need to do that four times. And again, each time I might need to do some tabbing in order to make sure I'm getting the correct thing. But I want to be able to lock that in all four directions. And that eliminates most of the automatic sketch dimensions as we would expect. Now one automatic sketch dimension remains right here, marking where the center of this arch would be. Now, the trouble is that in order to calculate where the center should be for a segmental arch, you'd have to actually do a lot of math. It's definitely possible if you Google radius from a cord length online, you'll find that if you know the cord length here, that's our W, you can use that to calculate what this radius should be and that distance, and therefore you could build a parameter to set that for you. That's actually the hard way to do it, okay. Now we will look at examples of using formulas later in the course but for now, there's a much simpler way. Now unfortunately, it's not as simple as just using align and lock because we can't align to the quadrant point of a curve. The only points you can align to on a curve are those endpoints that were at the either ends here. So I'm going to click the modify tool to cancel out of the align command and even though I can't do it with the align command, I can do it with dimensions. So what I'll do is I'll just use an aligned dimension, and you actually have two options here. You can use the top reference plane, move your mouse near the curve, and at some point it will highlight the curve itself. That's when you want to click. That'll create a zero dimension. When you place it, the automatic sketch dimension will disappear and if you do it to the top reference plane like this, you want to lock it. By locking it, what that does, let me cancel the command and open family types, is that makes sure that the top of that curve always stays attached to the reference plane. Let's go ahead and flex it and as you can see, that changes the shape of our arc. Now the other way that you could do it is to remove that dimension and of course, that brings back the automatic sketch dimension, but then I'll make a new dimension from the spring line also to the sketch line, place it. This time, you do not want to lock it, but what you do instead is select that one and label it with that same H parameter. Now that will give you exactly the same result when you flex. Either technique is perfectly fine. So it's a matter of personal preference. Which one do you like better? And there really is no advantage one over the other. But the point is that what we're doing here is actually breaking my standard rule of thumb. Now you may recall that I always recommended that you dimension to references. So your dimension should go from reference to reference from reference plane, reference line, or level didn't matter but it's got to be reference to reference. You want to avoid dimensioning directly to geometry. Well in this case, we're dimensioning directly to geometry. So clearly there are times when there are exceptions to the rule, but you need to know the rules before you know how to break them, right? So in this case, this is an appropriate place to quote on quote break the rule and make that exception. And with experience in the family editor, you start to learn where those things are. Controlling parametric curvatures, definitely one of those places. So I'm going to go ahead and finish that path, and then I just need to draw the shape of the object that I want to sweep. So I'm going to keep that really simple and I'm going to do that in 3D. So in 3D, I'm going to zoom in, click edit profile, and I'm not going to make this one parametric in this example. I'll just simply eyeball a rectangle shape, click finish a few times, and that gives us our arch. Now I'm going to do W T to tile those two windows, and I'll zoom and pan a little bit in each view just so I can see them better, leaving some room over here to open family types so that we can flex everything and test it out. So let me try a couple values for the H parameter. So if you want to make a shallower arch, you can do that by just adjusting that with a smaller value. I can make it even shallower by stretching out the width or I can make the width a little narrower. And you can see that as you flex both W and H, the shape is adjusting and keeping that sort of segmental proportion. Now we're not using the D parameter for this particular example so that one would have no effect but there is this default elevation parameter here which is currently set to four units. Now that's a built-in parameter for the face-based family. So let me show you how that one works to finish this up. I'm going to go to save as, family, I'm going to put this on my desktop, give it a name, and then save it. Then let's load it into our project. This is going to be our sandbox project and because we're in a 3D view, then the choice that becomes available is place on face. And as we've already talked about, you can certainly place it on this face or this face, but the appropriate face is this wall here. Now, if you go to level one floor plan instead, let's just zoom in a touch, and then go to the component tool, make sure that your segmental arch is loaded there, that gives you a new option, place on vertical face. And that's where that default elevation parameter comes in. So I can click anywhere on the surface of the wall here and place it in plan view but what actually that did was, if you click on it, it placed it at that default elevation of four units and if you go back to 3D, you can see where it placed it in that vertical location. That means that if you click this one, the location that it used there was just somewhat random based on wherever I happened to click in 3D. Now you can always change that later and that will adjust the position of that arch. So that's entirely up to you. So whether or not you prefer to place them in plan view or 3D view really is a matter of preference. So building a segmental arch is really a simple form to create, it's just a matter of building a sweep with a constrained arc path. Now in the next few videos, we'll look at a few more examples of other kinds of arches that we can create in a similar fashion.