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Using fixed proportion and scaling

From: Revit: Family Curves and Formulas

Video: Using fixed proportion and scaling

In this movie I'd like to talk about proportional scaling. And click OK.

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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This video is part of

Image for Revit: Family Curves and Formulas
Revit: Family Curves and Formulas

38 video lessons · 1178 viewers

Paul F. Aubin

Expand all | Collapse all
  1. 5m 3s
    1. Welcome
      1m 21s
    2. What you should know before watching this course
      1m 36s
    3. Using the exercise files
    4. Units of measurement used in this course
      1m 16s
  2. 42m 42s
    1. Creating seed families
      8m 22s
    2. Understanding automatic sketch dimensions
      7m 43s
    3. Creating circles
      7m 44s
    4. Creating ellipses
      5m 18s
    5. Constraining simple open curves
      9m 8s
    6. Using arc angles and radius
      4m 27s
  3. 25m 56s
    1. Controlling rotation
      7m 39s
    2. Creating a door swing
      5m 12s
    3. Adding geometry to work planes
      6m 32s
    4. Rotating a curve
      6m 33s
  4. 32m 6s
    1. Working with segmental arches
      9m 29s
    2. Creating Roman- and Moorish-style arches
      3m 26s
    3. Creating the framework for a Gothic-style arch
      3m 35s
    4. Making a Gothic arch
      7m 50s
    5. Making elliptical arches
      7m 46s
  5. 36m 35s
    1. Introducing formulas
      7m 16s
    2. Using profile families
      5m 53s
    3. Devising the strategy for ovolo curves
      4m 31s
    4. Building an ovolo profile
      11m 22s
    5. Using an ovolo profile to shape a sweep
      7m 33s
  6. 16m 34s
    1. Understanding cyma curves
      4m 58s
    2. Building profile references for a cyma curve
      5m 38s
    3. Building a cyma profile family
      5m 58s
  7. 38m 21s
    1. Using fixed proportion and scaling
      6m 19s
    2. Leveraging equality dimensions
      6m 51s
    3. Understanding splines and fixed proportions
      8m 49s
    4. Incorporating variable proportions
      8m 4s
    5. Combining scale and proportion
      8m 18s
  8. 33m 26s
    1. Creating a three-center arch
      5m 52s
    2. Using a profile to make a door opening
      6m 37s
    3. Creating a profile-based door panel
      4m 54s
    4. Configuring molding profiles
      6m 26s
    5. Creating door molding sweeps
      9m 37s
  9. 1m 6s
    1. Next steps
      1m 6s

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