Join Paul F. Aubin for an in-depth discussion in this video The family creation process, part of Revit Architecture: The Family Editor.
Now that we've explored Annotation Families and we've seen many possibilities that exist that can accommodate nearly any office standard, it comes time to turn our attention to Model Elements. Most of the families that you're going to want to create are probably going to be Model Elements. Using the Revit Family Editor, we can not only model nearly any geometric form, but we can base the geometry on rules, constraints and other logical relationships. We call this making it Parametric. Parametric Families are at the heart of what makes Revit so powerful. So in this chapter we're going to lay down the foundation of the skills that we're going to need to begin making fully Parametric Component Model Families and we'll start that with just an overview of the process.
So the first thing is deciding what you need. This can take the form of hand-drawn sketches, look at other objects and mark them up. You can download things and use those as a basis. Whatever process you use, but you identify the need, you decide how you want the item you're going to create to behave, and you document that in some way either through sketches or other forms. When it comes down to actually jumping into Revit and using those sketches that you've determined, there are a couple of key things you're going to be deciding. Now we saw in the previous chapter creating Annotation Families that when we first create a family, it takes us to the Family Templates folder.
When we go to the Family Temples folder, we're actually choosing two things, when we're doing a Model Family, where with the Annotation Family we were really only choosing one. With the Annotation Family we were just saying what category of Annotation we're creating, but here with the Model Family we're also choosing the category from the template that we select, but we're also choosing the hosting behavior. So what is the hosting behavior? Well some Families require a Wall host; some Families require a Ceiling host or a Floor host.
If you choose a template that requires a host, then the Family you're building will be required to be attached to that kind of a host element when you put it in a Project. So it's pretty important decision and you're being enforced to make that right away at the beginning. So it's something you want to think about carefully before you get started, and we'll see some examples of that shortly. Once you're in the Family, the next step is laying down the Reference Planes. Now you can think of Reference Planes as really the framework or the formwork, the skeleton; all of these words kind of mean the same thing. Formwork determines the shape and extent of poured concrete, and the skeleton of course determines the shape and the form of our bodies, and so whatever form, scaffolding sometimes people use, whatever analogy you use to represent the Reference Planes, they literally are determining the overall form and behavior of this Family.
We're going to then add Parameters and Constraints to that formwork, and that's what's going to give us the smart or the flexibility in our Families. So another way we call this as making the Family flexible. That's going to mean that it can adjust and change shape and move in size. So we do all this sort of preplanning and set up before we finally get around to building geometry. So building geometry may be one of the first things you think you're going to do, but it's actually one of the later steps. You want to get everything set up and established correctly first and then go in and actually add the geometry.
If you've got a properly structured formwork and set up, adding the geometry becomes much simpler, because it will relate to that formwork that you've established. And then the most important step of all is to flex your Model or test it out. Okay, so if we're making a Family flexible by adding Constraints and Parameters then the process of flexing it just simply means that we're actually going to put it through its paces and make sure that everything is working and behaving the way that we expected it to work. Those are basically the overall things that we need to consider.
It's essentially like the back of a shampoo bottle at this point: lather, rinse, repeat. So once you've done these steps, you just do more of the same. And so in the next movie, we're going to go in and we're actually going to perform these steps, start creating our first Model Family, and we'll be doing that throughout the course of this chapter. It'll actually take several movies for us to build our first Model Family.
- Understanding family concepts
- Creating an annotation vs. a model family
- Adding geometry
- Working with reference planes and constraints
- Creating extrusions, blends, and sweeps
- Creating parametric relationships
- Editing element visibility
- Building complex families
- Adding conditional formulas
- Creating towers and arches