Using fixed proportion and scaling
Video: Using fixed proportion and scalingIn this movie I'd like to talk about proportional scaling. So, all of the families that we've worked on so far throughout the course have had flexibility in at least two directions, the X and the Y, and in some cases we've added other parameters as well. But, in almost all cases, if we flex the X or the Y, it has no impact on the other. In other words, we're able to stretch our families in any way that we want, we have complete freedom in both directions. Well, there may be times when you want to actually set up certain fixed proportions.
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Have you ever tried to control the shape of a curved form in the Family Editor? If so, you know that flexing them sometimes throws you a curve ball. In this course, Paul F. Aubin explores several techniques to tame your unruly parametric curves. This includes examples of circles, arcs, arches, splines, and even complex curves like cyma moldings. The real power comes in with formulas, profile families, and proportions, which allow you to mathematically control your curves. At the end of this course, we can't guarantee you'll never have misbehaving curves, but we'll give you several useful tools to help tame them.
- Creating seed families
- Creating circles, ellipses, and arcs
- Controlling rotation
- Working with segmental and elliptical arches
- Using profile families
- Working with cyma curves
- Using fixed proportion and scaling
Using fixed proportion and scaling
In this movie I'd like to talk about proportional scaling. So, all of the families that we've worked on so far throughout the course have had flexibility in at least two directions, the X and the Y, and in some cases we've added other parameters as well. But, in almost all cases, if we flex the X or the Y, it has no impact on the other. In other words, we're able to stretch our families in any way that we want, we have complete freedom in both directions. Well, there may be times when you want to actually set up certain fixed proportions.
So, you always want the height to be twice the width or something along those lines. You could do that very easily by just setting up formulas in the family and if you did the trigonometry formulas that we did in the previous chapter, then these are pretty simple by comparison. But in this movie, I'd like to go through some examples of building the proportion, you know, sort of a fixed proportion, directly into the profile families that we're going to use. So in a file here called Profile Flex. And, it's just using a square profile right now. So, if I select this sweep on screen here, and scroll down.
You'll see that I've got a profile called Rectangle Profile. And then it's got a type called eight by six. So, you could see that down here on the Properties panel as well. Here's the Rectangle Profile family. Here's the eight by six type. And if I right click and edit its type properties, there's the eight and there's the six. Now, there currently is no limitation, so if I decided to change X to 1.2 and click OK, it will happily stretch the X direction without any impact on the Y. So, what I want to do is, set up a relationship where, if I change one, it actually modifies both of them.
So, let me reset that back to 0.6. And click OK. And I'm only doing 0.6 so it matches the name. And then, let's right click Rectangle profile and I'm going to choose Edit. And that will open that family. And, of course, you can see that there's a Y direction and an X direction. And, we just have a really simple rectangular shape here. To do this, all you need to do is go to Family Types and put formulas in right over here. And we've seen some examples similar to this before, so this is not a terribly new concept here.
But, let's go ahead and put in a formula. So, if I wanted to maintain this proportion that you see on screen here, I could say that it's Y times 0.75. And you'll notice that nothing changes on either side because I've done the calculation to maintain that proportion. But now if I click in either field and I put in a new value, it will also change the other one. Now, it goes both ways when you do these simple arithmetic formulas. So, if you come in here and you put in 0.5, that will force the Y to change as well.
So, by putting in a single formula, you're actually tying both values together and it works in both directions. That's not true of every formula you create but it is true of any arithmetic formulas, they always work bidirectionally. So, if I apply that. Very simple. Now, if I were to load this back into the project, it would be maintaining that proportion. So now, eight by six doesn't really mean a size per say, it's more of the relationship. So, perhaps I want to rename that and, instead of eight times six which kind of implies that those are fixed numbers, I'll put in eight by six, which, maybe implies that that's more of a proportion.
Okay, and I'll click OK and I'll load this back into my project, overwrite the existing and, when I do, nothing really changes too much on screen here and an interesting thing happened down here on the project browser. Now, this is something you may be familiar with, if you've worked in the Family editor before. The eight by six type that was already here, we renamed it in the Family editor. But it's still here. So Revit won't delete a type that you already have. And it certainly wouldn't delete it because if you look at this sweep, you can see that it's actually still using that type.
So, if Revit deleted that type on us, it would actually delete our form. So, they won't go ahead and delete that type, but now I could switch to this one. And when I apply, you can see that the shape just adjusted a little bit because it's now using the new proportional one. So then, this one is no longer necessary. I can simply delete it, but its kind of important to understand that, that if you create a new type in the family editor that's different from the type you created in the project, you might end up with some of these left over types hanging behind.
So, it is a good idea to clean that up. But anyway, if I right click here and go to Type properties now, even though I'm no longer in that family editor, if I change the values here, the formula stills applies. So, I can't make these go out of sync. No matter what number I put here, it's always going to maintain an eight by six relationship. And so, that's a really easy way to build in proportional scaling, directly in the family. Now, you can do that with any of these profile families.
So, I've provided a few others for you to experiment with, if you'd like. Like the Ovolo profile and the Kima profile in the exercise profiles. It works exactly the same way. If you wanted to, you can come in here and put in the same relationship. Y times 0.75. Not going to change any of these formulas, but that just adds one more constraint, if you will, on the entire family. So now, regardless of what I edit either of these values to, it stays in this eight by six proportion.
And that's the only real change we've made. Meanwhile, depth is still unaffected. So, notice here that the depth can still be anything that we want it to be. So, if you also wanted depth to flex proportionally, you'd have to give it a formula as well. And it could also be something like, you know, 0.5 plus Y times 0.75, or whatever relationship you're trying to achieve. But it's as simple as that, if you want to get proportional scaling. You just have to take each of the parameters that want to be related to one another, and make sure that they have that proportion built into them, by just putting in a formula.
It can be division, or multiplication. They both work the same way. But it's going to be a bidirectional relationship.
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