What are prefabs?

- [Instructor] When creating a project in Unity, there are times when you may want to reuse assets and that is to be able to quickly populate a scene with some of their objects or something that you're going to be reusing several times. Now, the issue with just dragging and dropping a model, repeatedly throughout a scene, is that you have issues of things like draw calls or if you need to change those objects, you have to change and edit each one, individually. This is where prefabs come into play in Unity. So, prefab, just in it's most simplistic ways, is a collection of predefined component.

So, game objects and components that are reusable throughout your scene. So, you can reuse these elements throughout your project. Let's take a look at an example of some prefabs in here. So, if we go to the Standard Assets folder, that you brought in, and we can look at things like the first person character in here and there's a prefabs folder. So, the first person character control has in there, a number of different elements. I'm just going to drag and drop it into my hierarchy here. We're not going to do anything with it specifically but I'm just going to open it up and take a look at what it has.

So, what it has set-up in there is a bunch of different things that are all packed together, so I could reuse this throughout a scene if I wanted to. If we go out even further here, and take a look at something that we're going to be using quite a bit later, we can use this third person prefab and by clicking on this and opening this up, you can see that this prefab has a model in it. It also has a skeleton with rig information on it to animate this guy, and it has different pieces of components in there. As well with the prefab, it has access to everything related to it.

So, anything related to specific materials in there, or anything related to the specific animations or how that object or several components are going to work together. So, I'm just going to actually remove these guys from our scene in here. So, the basics of a prefab are that it's a way to reuse elements and it's a way to rapidly update elements throughout a scene. So, if I had for example, this barrel, I could populate the scene with a prefab of that barrel and change that barrel as needed, or maybe three variations of the barrels.

So, three prefabs and just make one change on each one and have a blue barrel, for example, or whatever it may be that I want to do. So, that's an overview of what a prefab is in Unity. We're going to take a look at how we can build them, how we can export and import them, and use them to build our scene as well.