Constraints and Dimensions

Name: Constraints and Dimensions
Author: Patrick Porter

Discover different methods Revit uses in dimensions to add constraints to your model

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Course: On-Demand

Hello. In this chapter, we are going to discuss constraints and dimensions in Revit. And in this particular lesson, we're going to talk about the differences between the constraints and dimensions. Before we get started. I'd like for you to note, that I have opened up Revit LT 2022. And I have the arc link model opened up from our exercise files. So once you get that opened, let's go ahead and follow along, please. So as you can see here, I have opened up the entry level view from the project browser. And in here, there is a lot of dimensions for all of our elements. Dimensions are used to show measurements within our projects. And there are two types of dimensions in Revit. You have your permanent dimensions, which are dimensions that we've added to our drawings to document the design intent. And they are view specific. And they are going to print on sheets. They will display it, they always will stay displayed on this sheet until we delete them. The second type of dimension is a temporary dimension. And these dimensions are the measurements that display in the drawing as we place elements or sketch lines, or when we select elements. So for example, if I was to select this door over here. We have these blue dimensions, which are temporary dimensions. If I deselect this door or just press the escape key, those dimensions disappear again. Let's select the door again. And these are the temporary dimensions that we can use to further move this door, if I wanted to. So I can click in here and I can change this dimension. Let's say if I was to change this to seven instead of eight feet. Press enter. And then that door will move when I click away from the door. So it's no longer selected. The temporary dimension goes away. Let's go ahead and move that door back. So I'm going to select it. I'm going to click this temporary dimension, and I'm going to change it back to eight feet. Press enter, and the door moves back. We can also, with this door selected, make one of these dimensions a permanent dimension. By clicking on that symbol there, these dimensions are now permanent dimensions. So when I click away from the door, those dimensions still exist. Let's select the door and we can adjust the dimensions again, if we needed to. Or if we select the dimensions, we can lock the dimension to create a constraint. Constraints are used to add intelligence to the elements that we're modeling by defining a relationship between the elements. So with this locked dimension here. I'm basically saying that we can't modify this door by moving it. Because it's going to remain eight feet six and a half inches from here. Now with this dimension locked, I can no longer modify this dimension. So if I was to come and try and change this back to seven. I'm going to get an error message that says, "Can't change the dimension segment to this value." Let's hit cancel, here. Select the door. We can unlock this dimension to remove the constraint. Now I can change the value, and we don't get a error message. Constraints are non view specific elements, and they function independently of dimensions. Whereas dimensions are view specific elements. Constraint elements appear as blue dash lines in all views in which their references are visible. Sometimes constraints can be modified and deleted, as you just saw here. In this case, I just removed the constraint by unlocking the dimension. And that constraint no longer applied for this dimension. Constraints also apply to the entire model objects that you've applied the constraints to. They're not just stuck on that particular view. So if you apply a constraint to this door where this dimension is locked. Then this door is always going to remain at this dimension unless we unlock the constraint. So constraints are best used to create relationships that capture the design intent. Also, once you've created constraints between multiple elements. They will always move together when you make modifications to those elements. So those elements are going to maintain the relationship until you remove that constraint. For example, let's create a wall over here in the cafeteria. I'm going to type W, A to start the wall tool. Just going to come out from here. I'm going to come down to right about here and snap in right there. Press the escape key to be done with this. I'm going to move this wall, right here. That I snapped. Let's move it up a little bit. And then let's trim these pieces. Hit the escape key. Now let's come over here to modify. And the align tool that we've used before. Let's click the align tool for this wall. Let's select this front face of the wall here to be aligned to this front face of the wall here. So I'm going to actually select this front face, as the alignment. There is the dash blue constraint line that this alignment is about to create. And then I'm going to select this to say that I want this face to be aligned to here. And it's automatically locked. Notice that this lock indicates that it is now an alignment constraint. Let's hit the escape key. I can select this wall, and you'll always see that it has a constraint applied to it. Thanks for watching this lesson. Join me in the next lesson where we will discuss more about creating constraints by locking dimensions.

Intermediate Provider : Patrick Porter 5 Lessons · 39m in Arabic, German, English, Spanish, French, Portuguese, Urdu, Chinese

Course Description

In this Constraints and Dimensions course, you will learn the differences between constraints and dimensions in Revit. You will learn how locking dimensions create a type of constraint and explore several methods of adding and locking alignments to also create a constraint. We will learn to adjust and enforce equality among a chain of dimensions to create an equality constraint. The lessons will finish by demonstrating ways you can reveal all the constraints that have been applied to a view.

In Revit, dimensions are not only used to indicate angles and distance, but they can also be used to constrain and locate elements in your models. Unlike most other traditional 2D design applications, Revit dimensions cannot be faked. In those traditional 2D design applications, mistakes generally occur when different views are not coordinated properly. Revit assists in the coordination of your views because every view created in Revit is just another way of looking at the building model. So, a change in one view is a change in them all. This course will show you how best to keep your model elements coordinated by creating and using dimensions to constrain elements that help you capture the design intent by locking in critical relationships between elements.

What You'll Learn

Distinguish the differences between constraints and dimensions in Revit
Create constraints by locking dimensions in your model
Add and lock alignments to create constraints
Build equality constraints by enforcing equality among a chain of dimensions
Reveal all constraints that have been applied to a view

Key Takeaways

In Revit, dimensions are used not only to indicate angles and distance but also to constrain and locate elements in your models.
Locking a dimension creates a type of constraint in Revit.
Unlike traditional 2D design applications, Revit dimensions cannot be faked.
Every view created in Revit is just another way of looking at the building model, so a change in one view is a change in them all.
Using dimensions to constrain elements helps capture design intent by locking in critical relationships between elements.

Frequently Asked Questions

What does this course cover?

It covers the differences between constraints and dimensions in Revit, creating constraints by locking dimensions and by adding and locking alignments, building equality constraints by enforcing equality among a chain of dimensions, and revealing all constraints applied to a view.

What skills will I gain from this course?

You will gain skills in constraint layout, constraint management, dimensional analysis, dimensional modeling, dimensioning, and geometric dimensioning and tolerancing.

How does Revit help keep model elements coordinated?

Because every view in Revit is another way of looking at the building model, a change in one view is a change in them all; the course shows how to create and use dimensions to constrain elements and lock in critical relationships.

What lessons are included in this course?

The lessons are: Differences Between Constraints and Dimensions, Creating Constraints by Locking Dimensions, Creating Constraints with Alignments, Creating Equality Constraints, and Revealing Constraints in Views.