Creating massing forms in Revit Architecture

Creating forms is the most basic skill you need to develop when working in the Conceptual Massing Environment. Form making in the Massing Environment differs quite a bit from the standard Revit Project Environment or the Family Editor. Therefore, the focus of this movie will be on the basics of form making. We will not be building anything particular, but rather we're going to learn the concepts required and the techniques required to create many common forms. Now I am going to start with some of the forms that you can create in the Standard Family Environment like, extrudes, blends or sweeps.

Now you may recall if you've watched some of the previous movies that we have a single Create Form button. So how does it know whether you wanted to do an extrude or whether you want to do a revolve or whether you want to do a blend? Well, it largely guesses based on the objects that you draw, the shapes you draw and how you select them. So I am in a file called Create Forms and it has several shapes in here already to get us started, so that will help us speed things along. From previous movies, you may recall that what's required to create form in the Massing Environment is you set your Work Plane, you draw your sketch, and then you create form.

I've already got several sketches here, they are already established, most of them to this Work Plane. So I am just going to simply select the form that I want to create and then come over here and click Create Form. And at its most basic it will guess what the appropriate form is and simply create it. Now in that case, we just had a basic rectangle and there was really only one thing that it could do with that, it could extrude it. Now, if I came over here, did the same thing with this form, it will just simply extrude it again. But what would happen here, if I selected two forms, stacked on top of one another.

Now for if I just kind of take a quick look at this, orbit it around, what you see is, those things are stacked relative to one another. In height, one of them is associated with this plane; the other one is associated with this plane. If I do Create Form there, I get essentially the equivalent of a blend. So in the traditional Family Editor Environment, you would click the Blend tool and then you'd sketch your base and then you'd sketch your top. Here in the Conceptual Environment, you set your Work Plane, you draw your first shape, cancel out of there, you set your next Work Plane, you draw your second shape, and then you select these two, and there is really only one thing that Revit can give you with this and that's a blend.

And you can see here that it blends between the rectangle and the circle in much the same way that it did with little pyramid shape right here. So that's the basic idea, so again I've just got the forms here just to move things along a little bit. We saw in previous movies that in some cases when you choose something, you'll get more than one choice, so there was really no ambiguity with any of these forms here, but this one could either be a cylinder or a sphere. So I can choose whichever I prefer.

There's another way to create a sphere as well, so that was certainly one way that I could do it, where it basically revolved that circle to give me a sphere, but if you look over here, you'll notice I've got a line and half an arc, and I've got a similar version of it here with another line and have an arc, but this one you'll notice has a line connecting the arc there, this one does not. So the difference is that technically these two shapes here, and let me do it with a window selection. Technically, what I am going to get here is actually a surface revolve.

When I do Create Form, there's really only one thing that it can give me. Notice that it didn't actually show me multiple glyphs, because the only thing it could do with that, and it was really this straight line that was the giveaway, is revolve that arc around to form a sphere. So with this shape, the difference is that I actually have two lines, let me zoom in slightly here to show you. I actually have two lines there, this one and this one, and so really if we select just this portion right here.

If I were to just go right to create form with only that, it would actually extrude that, because it would assume that that's what we had in mind. If I undo that with Ctrl+Z and I select everything including this line here, then it makes my intent a little bit more obvious and I end up with a revolve again. So you'll notice that the same basic shape by introducing this additional line that becomes an axis line, there is really only one thing that Revit can properly assume to do with that, and that's to turn it into a revolve.

So sometimes, when answering that first basic question, how does it know what shape to create, sometimes you have to kind of help it along by introducing an additional bit of line work to kind of get what you intend in mind. Again, sometimes it will not be clear, it will give you more than one choice and in this case I could go to the cylinder, other times you're going to have to make it clear by introducing that additional shape. Now what about a sweep? Well here, if I zoom in on these two little S-curves over here, I've drawn the S-curve in two different ways.

In this case I have a chain of lines and arcs. So here, if I do my Tab key, there is one arc here, there is a line here, and another arc here. Here, I just have a spline, a continuous spline. Now in both cases, I am going to select this polygon and then the chain with the Ctrl key and go to Create Form and that gives me a sweep. Here's the spline with the hexagon, Create Form and there is a sweep. But notice the difference between these two when I zoom in.

Here, I've got a seam where it went from arc to straight line, back to arc. Here, it was seamless, because I'm sweeping along a continuous spline. So if the seam is important to you and you want to avoid getting the seam, then this is the approach you have to take as you can use a spline. Now if I direct your attention over here to the toolbox, we have two kinds of splines, we have the spline with the control handles, and this is more of like a Bezier curve, and we have this one Spline Through Points. So there's actually two ways you can create the curve and both would give you the same result here, but it's just a different kind of curve and you can feel free to experiment with those.

Now something that you can't really easily do in the traditional environment is what would be termed a loft in most 3D applications. A loft is where you create multiple shapes like multiple cross-sections and then essentially do a continuous blend from shape A to B to C. So to do this in the traditional family environment, I would have to blend from the first rectangle to the second and then from the second to the third. But of course when I do that, I would get straight segments in each case.

In other words, if I take this guy like this and do this, you see how I get a straight line here. I am going to undo that. But if I select all three together, and do Create Form, then Revit will actually average the path between the three shapes and it'll have this curvature to it and that's more of a loft. So you actually do get a quite different result when you select all three shapes at once. And if I select this guy and kind of spin it around a little, you can see that the three cross-sections are still in there as rectangles, but they have that curved path which blends between each of the three.

So it would be much more difficult, if not impossible, to get that form in the traditional Family Editor. Okay, so that's sort of something that's pretty unique here in the Massing Environment. Now we already talked about this in a previous movie, but I just wanted to remind you that if you use your Tab key, you can select just a single edge and then if you create form what you get instead of a solid form is you get an individual plane. Okay, and if I select the others, they will extrude separately and I get an individual plane there. So it becomes like a hollow shape there.

Now, what about something like a pyramid form? Now, by the way, what I'm doing here is a little trick here. I want to point out is if you select something first and then hold down the Shift key and drag your wheel, it orbits around what you have selected. This is a much better way to control your orbit. If I didn't have anything selected and I do that, you see how I am kind of orbiting around the center point, and sometimes the thing that you're trying to look at could spin right off screen. But if you select something first and you orbit, then it centers the rotation around there.

So it's usually a better thing to do if you can remind yourself to always select something first. Now what I have here is a square here and a really tiny square up above it. To get a pyramid shape, there really isn't any way that you can extrude from a square to a point. So if your pyramid has a little top shape here, then you could do it with a blend. But what you'll see, if I zoom in, is that I do have this flattened out top surface there. Now technically speaking, if we were going to go build a pyramid, it probably wouldn't end at just a perfect point, so that might actually be appropriate.

But if you actually wanted it pointed, then what I am going to do with these shapes over here is show you how we could do this using a combination of solid forms and Void Forms. And this will give us an opportunity to also talk about voids, because up until now, all the forms we've been creating we've been using the solid. So, I am going to start with this one and it was drawn on a vertical plane, which is actually buried under here somewhere, there it is right there. That was drawn if I use the Tab key on a reference plane, which you can see is kind of buried underneath there and that's where this triangle was drawn.

And so it's pointing straight upright, and I'll just do Create Form for that. And you can see that it's only a short depth of about 10 feet there. I could type in directly some number or I can use these control handles and actually snap it, and you could see right there that it's snapped to that plane. Let me show you that again. If I back it off a little bit and kind of pull it forward, you can kind of see it highlighting when I get close by, so it snaps right to that, and it turns out that was 28 feet, so I could've typed that in.

And so that gives me just an extruded wedge. Now I am going to create a Void Form and I do that by selecting one of these triangle shapes here, which was also drawn on a vertical reference plane. Go to the dropdown here, go to Void Form, and it again creates just a short depth void, in this case it's only about 7 feet, and what I am going to do is simply take this grip here. And you can kind of see it cutting through as I drag, so if I stop short, it kind of did it, but you notice how it doesn't look like it's doing anything, you've got to deselect it to see the effect.

So you can kind of see that it's only cutting halfway through. Now if I want to adjust it later, I've got to move my mouse over here and Tab, and I might have to do it a few times to get back to the void, it's still there, okay. And I can tab in to that face again, right there, and continue to stretch it so that it cuts all the way through. And again, the effect is concealed while the void is selected, but as soon as you deselect the void, it applies the cut, and if I select this and spin around, you can kind of see the effect there.

So I just need to repeat that process with this one, make it a Void Form, stretch it all the way out here, deselect. Select something so that I am orbiting around it, and there is a pyramid that has a point at the top. So it's a slightly different approach to the issue. If having a flat top bothers you, then you can use a combination of solids and voids there. So as you can see that basic form making in the Conceptual Massing Environment is easy once you know the process and workflow.

It does take a little bit of getting used to at first, but the basic idea is begin with an idea of what you want to create, set your active Work Plane to draw one or more shapes. You select those shapes, either the one shape or multiple shapes and use the Create Form button and that gives you your form. If you want a Void Form, you use the drop down and you create Void Form. And that gives you something that will cut away from a Solid Form. So with a little bit of practice even complex forms can be created quite efficiently.