Join Paul F. Aubin for an in-depth discussion in this video Using the Is Reference in families, part of Revit: Tips, Tricks, and Troubleshooting.
- [Instructor] If you've ever worked in the family editor before, then you've certainly worked with reference planes. Now, you may or may not have noticed that the reference planes have a feature called Is Reference, and this setting controls some very subtle but powerful behavior on how those reference planes will behave when they're inserted in files, when they're dimensioned, or when you use the Align tool. So I'd like to look at some of those nuances here, and to do it I have a few different families loaded in this simple file. So we're going to start here with this family, which is just the out of the box desk family.
Okay, it's a very simple family file. So let's zoom in nice and close here. Now let's say you wanted to dimension this desk. Now, when you dimension an object, it will sense the location of any reference planes within that object. So let me run my dimension tool, and I'll start to move my mouse around the desk in some of the obvious places, like the edges, certainly, should not be surprising that we can dimension to those points. But you can also dimension to the center of the desk, and maybe a little bit less obvious, there's actually a reference plane over here and another one over here, and there's actually one floating out here, kind of away from the edge of the desk.
Now, those reference planes are within the family, and they're configured in exactly the same way as the edges or the center lines, which is why all of them are eligible for dimensioning here. Now, by the way, the Align command will sense all of the same things. So there's the edges, the center lines, right, so you can use the Align command, you can use the Dimension command, to get access to those reference planes within the family. So let's take a look at the reference planes in this desk family, then. So I'm going to select the desk, let's do Edit Family, and then I'll go to the Floor Plan view.
Now, I want to point out that there's a pedestal here and here, and that's actually why we were seeing those lines kind of offset from the ends, because what those actually are are these reference planes that go right down the middle of each of those pedestals. We've got this one here, and we've got this one here. Now, those may be useful to help us build the family and structure it and have it flex properly, but we may not need them for dimensioning purposes. So if you don't want to be able to dimension those reference planes, or if you don't want somebody to be able to align to those reference planes, then all you have to do is select them, come over here to the Properties pallette, locate the Is Reference feature, and change this to Not a Reference.
I'm going to do the same thing with this one that's up here, which if I zoom in you can see what it's controlling. That's actually the thickness of that drawer front on the front side of the desk. So we really don't need to dimension that, so I will set that to Not a Reference as well, and then let's load this back into the project and overwrite the existing. Now when I go to the Dimension command, I'll no longer be able to see the drawer fronts, but I am still able to see the front edge, the left edge, the right edge, the center, the center, but notice that I'm no longer able to see the centers of the pedestals.
So now this desk has more reasonable locations for its dimensioning points and we were able to do that by just simply changing a really simple setting on the reference planes within that family. So let's zoom back out here and talk about some of the other features that are available with Is Reference. Now, another feature that we have is this notion of strong or weak references. So if we take a quick look at the help file, you can search for Is Reference, and you'll get this article right here which talks about what a strong, a weak, and a not a reference is, and then it lists out the various kinds.
Now, there's only one weak reference, only one not a reference, but there's several different options for strong references. So let's start off with the generic strong reference compared to the generic weak, but then we're also going to look at left, right, center, front, back. So generally, if you're building a family, and you know which side is the right and which side is the left and the front and the back, you ought to use those designations for the Is Reference. It'll be more consistent and it's considered more of a best practice. And I'll also show you a practical reason why that is in just a few moments.
But if you have an irregular shaped family, or something that doesn't lend itself to those descriptions, left, right, front, or back, then you can just resort to strong or weak. Now, a strong reference just means that it has higher priority for dimensioning than a weak one does. Okay, so right now, I've got two versions of the box. I have this one here called Box Strong and this one here called Box Weak. And I'm going to edit one of these, and go to the Plan view, and every one of the reference planes in this family I've just set to a strong reference, which is really not a good thing to do, because I've given them all exactly the same amount of priority, okay? So we wouldn't be able to see any difference whatsoever.
Now, if I switch temporarily back to the floor plan in this file, this one is set up exactly the same way but everything is set to a weak reference. Well, it doesn't matter whether it's weak or strong. If I switch from one to the other, the existing dimensions will work just fine. Where it matters is much more subtle. When you're actually in the act of dimensioning, you can use your Tab key and Revit will default to the strong references but then as you tab it will cycle through the weak ones.
So it's a much more subtle type behavior. So in order to really see that, let's switch back to the family. I'll take the four edges, and I'll set those to a weak reference, and then let's load that back into the project and overwrite the existing. Now, it would be very difficult to do this here with us zoomed in so close because you can just as easily move from left to right and center without any trouble at all. But if you were zoomed out far enough where it was a little bit more difficult to put your mouse exactly where you wanted, it's very subtle, and it's far away, I realize, but by moving my mouse, it's only highlighting the two strong references, which are the ones in the center line.
So if I kind of move my mouse nearby where there should be a weak reference and then press Tab, it'll go through the strong references first, but then it'll start to see the weak references that are nearby, and eventually I'll be able to tab through all of the different options and it eventually will get back to the center lines. So that's really the only difference between strong and weak reference is that by using your Tab key you'll be able to cycle first through the strong ones and then get to the weak ones, okay? So let's zoom back in, and now let's talk about the named references with these two shapes over here.
So here I have a wedge family that I just called Wedge, and this one I called Bowed. And they just have subtle differences in the shape just so that we can understand what's happening when we switch between. Now, notice that here I've dimensioned to one of the edges and here the center, and here a different edge. So what I want you to see there is if you configure your families consistently, then it shouldn't matter that they're dimensioned to different points if you switch one to the other. So I'll change the wedge to the bowed, notice that the dimensions are unfazed.
They will respond just fine. Let me undo that. However, if you're not consistent about this, then that's not always going to be the case. So what I'm going to do is I'm going to start off by adding a dimension here, so now I've dimensioned both the left and the right face of this object. Then I'm going to select this object, edit the family, go to the floor plan. Right now this one is set to right and this one is set to left.
I'm going to reverse them. So let's say that, for whatever reason, I wasn't paying very close attention and I got those backwards, okay? So I'm going to load that back into the project and watch what that's going to end up doing to our dimensions when we overwrite. So you notice how the dimensions just switched sides on me? Now, at the moment I do that, it might not be that surprising, and I might be okay with that, but where it's going to be a little bit less desirable is then later if you come in and switch it with another family, notice the dimensions will switch back again.
In other words, the dimension knows that it's on a left reference or a right reference and it will maintain that if the new family also has that left and right reference. So if you're consistent about the way that you build your content, then you'll actually have a good deal of control over this. And so that's really one of the very subtle but very important benefits of paying attention to that Is Reference feature. So best practice recommendation is whenever you build family content, try and think about where the right is, where the left, the front, the back, the top, the bottom, and set the Is Reference setting of your reference planes accordingly and then all of your content should behave in a much more consistent fashion.
NOTE: The exercise files for this course can only be opened in the most recent version of Revit (Revit 2017).
Skill Level Appropriate for all
Q: Why can't I earn a Certificate of Completion for this course?
A: We publish a new tutorial or tutorials for this course on a regular basis. We are unable to offer a Certificate of Completion because it is an ever-evolving course that is not designed to be completed. Check back often for new movies.