Whether you're a seasoned developer or just getting your feet wet, you've probably come across the term 'Unity Prefabs.' 🎮👾

So what's a Prefab, you ask? In Unity, Prefabs are quite the game-changer!

They are a core feature of Unity, allowing you to create, configure, and store a GameObject complete with all its components, property values, and nested GameObjects as a reusable Asset.

Why does that matter? 🤔 Well, imagine creating an intricate object like a player character.

You design it once, and then want to use it multiple times across different scenes or even different projects. Wouldn't it be handy to have this complex GameObject available at the click of a button? That's exactly what Prefabs are for!

🚀 You're about to embark on a journey exploring Unity Prefabs - from understanding their basics, creating and using them, to mastering more advanced topics like Prefab Variants and Nested Prefabs.

Stay tuned! 🕹️👨‍💻👩‍💻

So, how do you create a Prefab? It's super simple! First, you build a GameObject in the Unity Editor, adding all the components and properties you want.

Once you're satisfied with your creation, simply drag it from the Hierarchy window into the Project window.

Voila! You've created a Prefab! Your GameObject has now transformed into a reusable asset that you can use throughout your game.

To use this prefab, just drag it from the Project window to the Hierarchy or Scene window. You can use it as many times as you like, in as many scenes as you like. Pretty neat, huh? 🚀

Here's a fun tip! 🎩 If you want to make changes to your Prefab, you can do so by selecting it in the Project window and adjusting properties in the Inspector. And guess what? Changes automatically propagate to all instances of the Prefab used in your scenes. Talk about a time saver!

However, do you want to make a change to just one instance of the Prefab? No problem! You can select that instance in the Hierarchy and make your adjustments. But be aware, this creates what is known as a Prefab instance and the changes won't affect the original Prefab or other instances of it.

Let's say you've created a "Hero" Prefab that has properties like Health, Speed, and Armor.

To change properties for all instances of the "Hero" Prefab:

Let's say in one particular scene, you have a hero who has found a speed-boosting item. You want this hero to be faster, but only in this specific scene:

So, by manipulating Prefabs and their instances, you can create a flexible and efficient system for managing your game objects in Unity! 🙌

A Prefab Asset is like a blueprint or a template. 🗒️ It's created and stored in your Project window, and you can use it as a starting point to create multiple objects with the same properties and structure. If you've set up a super cool spaceship with all its components, scripts, and configurations and then saved it as a Prefab Asset, you've got your spaceship blueprint ready to go!

On the other hand, a Prefab Instance is like a copy of that blueprint, but in the real world (or rather, your game world! 🌍). When you drag a Prefab Asset from your Project window into your Scene or Hierarchy, you've created a Prefab Instance. This instance maintains a connection to its Prefab Asset, so changes to the Asset can be propagated to the Instance.

You bet! Now that you're a pro at creating and using basic Prefabs, let's raise the game a bit with Prefab Variants and Nested Prefabs.

Ever wanted to have a slightly different version of your Prefab? Enter Prefab Variants! 🚀

Just like the name suggests, a Prefab Variant is a type of Prefab that allows you to override and add properties, while still staying connected to its parent Prefab.

If you update the base Prefab, the changes propagate to the Variant as well, unless you've overridden those specific properties in the Variant. Neat, right? 😁

Creating a Prefab Variant is a piece of cake! Just drag a Prefab into the Scene, make your changes, and then drag it back into the Project window. Unity will ask if you want to make a Prefab Variant. Click 'Yes', and you're good to go! 🎉

As you can see from the image, the prefab variant icon it’s slightly different from the original prefab, so you can always identify which is which.

Let's use an example: suppose you have a 'Car' Prefab (parent), and you want to create a 'Race Car' Prefab (child).

You could create a Prefab Variant of the 'Car' and add additional properties, like a spoiler or a turbo engine. Any changes made to the 'Car' Prefab (like a new paint job) will propagate to the 'Race Car' Prefab Variant. But changes to the 'Race Car' (like a red spoiler) won't affect the 'Car' Prefab. Cool, huh? 🚗

The advantages of Prefab Variants include:

Nested Prefabs, on the other hand, are a fantastic way to keep your project organized. As you may have guessed, a Nested Prefab is a Prefab inside another Prefab. 🎁 This feature allows you to create more complex structures while still maintaining the convenience and efficiency of Prefabs.

Creating a Nested Prefab is as easy as dragging one Prefab into another in the Unity Editor. You can nest as many levels as you want, allowing for highly complex and modular designs. But remember, changes to a Prefab are propagated to its nested instances too! 🧐

Are you excited about the power of Prefabs in Unity yet? Up next, we're diving into some of the common uses of Prefabs!

Well, imagine a complex game object like a car. It's not just a single object; it consists of multiple parts—like the body, wheels, headlights, and so on.

Each of these parts could be a Prefab.

The body may have different paint jobs, the wheels could be of various designs, and the headlights might have several light intensity levels. Creating Prefabs for these components allows you to mix and match configurations easily.

However, managing these individual components could become overwhelming. This is where Nested Prefabs shine! 🌟

By creating a 'Car' Prefab that includes the 'Body', 'Wheel', and 'Headlight' Prefabs, you have a complete package—easy to manipulate and maintain. Changes made to the 'Wheel' Prefab, for example, will propagate to all 'Car' Prefabs, maintaining the hierarchical structure.

The advantages of Nested Prefabs are plentiful:

And hey, what if you have a Prefab instance and you want to disconnect it from the original Prefab? Well, Unity has got you covered! 😎👍

This process is called unpacking. When you unpack a Prefab instance, it becomes a regular game object and no longer receives updates from its original Prefab. This is useful when you want to make extensive changes to a specific instance without affecting others.

Here's how to do it: Simply select the Prefab instance in the Hierarchy, then go to the GameObject menu and choose Unpack Prefab. Bam! Your instance is now a standalone game object, free from the original Prefab's influence! 🎉🦋

In Unity, there are two unpacking options as you can see from the picture above, you can choose from: Unpack Prefab and Unpack Prefab Completely. They may sound quite similar, but they behave differently. Here's the rundown:

So, when deciding between the two, think about whether you want just the top-level Prefab, or all nested Prefabs, to become regular game objects. As always, the best choice depends on your specific needs and project structure. Happy unpacking! 📦

But remember, use this power wisely! Unpacking should only be done when necessary, as it can lead to more objects to manage and potential inconsistencies. So, always consider whether an override or a new Prefab variant might be a better option.

In Unity, whenever you change a property of a Prefab instance in a scene, Unity highlights that property in bold in the Inspector to tell you, "Hey! This is an override!" 📣

You want to see all your overrides at once? Simple! 🎉 Just click on the Overrides dropdown button located at the top of the Inspector when you've selected your Prefab instance. There you'll see a list of all the changes you've made. It's like your own Prefab override shopping list! 📋👀

Want to keep a specific change and make it the new standard for your Prefab? Click on Apply.

It's like choosing your outfit of the day and then deciding to make it your uniform! 🦸 But if you've decided a change was a mistake, just click on Revert to say "No thanks!" and the change will disappear faster than you can say 'Undo!'

A complex Prefab hierarchy can have multiple levels of Prefabs, each potentially having its own overrides. Unity refers to this as multi-level Prefab overrides. 🎛️

Imagine a Russian Doll-like scenario. You have a big Prefab (let's call it the outer Prefab), inside which there's another Prefab (the middle Prefab), and inside that, you guessed it, another Prefab (the inner Prefab). 🎎

You can apply changes to the inner Prefab that don't affect the middle or outer Prefabs. These are local overrides. But what if you want to change something in the middle Prefab that also changes the outer Prefab?

Well, that's where multi-level Prefab overrides come in. 🌀

It's like a ripple effect in a pond. You toss a pebble (make a change) and the ripples (changes) spread outwards to affect a larger area (the outer Prefabs). 🌊

Here's how to do it:

Multi-level Prefab overrides give you extreme control over your Prefabs, especially when working with complex hierarchies.

When you're working with Prefabs, there are a few tips and tricks that can help you optimize your workflow and the performance of your game.

With these tips in mind, you'll be a Prefab pro in no time! So go ahead, start Prefab-ing! 🚀

The following features are available from Unity 2022 and above.

Did you know that with Unity 2022.2, they've revamped the way you can replace Prefab instances? Now, it's as easy as pie!

Imagine you've got a bunch of tree Prefab instances in your scene. But then you think, "Wait a minute! 🤔 I have a cooler tree Prefab Asset that I could use instead". In the past, this could be a bit tricky and time-consuming.

But now, thanks to the updates, you can do it in a snap! Simply select the Prefab instances you want to replace in the Hierarchy or Scene view, right-click, choose "Replace With" from the context menu, and select the new Prefab Asset. Boom! 🎆 All selected instances are instantly replaced with your new Prefab.

The cherry on top? 🍒 Unity now also automatically matches the transform of the old instances to the new ones. That means your new trees will be in the exact same position, rotation, and scale as the old ones.

And remember, if you've made any modifications to the instances, they won't be lost. Unity will try its best to apply those modifications to the new Prefab, as long as the new Prefab has the same structure.

This functionality is not only available in the UI,but the guys at Unity made an API that allows you to manage how objects are matched, as well as how Overrides should be treated. See PrefabUtility.ReplacePrefabAssetOfPrefabInstance and PrefabUtility.ConvertToPrefabInstance.

In Unity, say you've got a Prefab instance in your scene, and it's a fancy car 🚗 But, oh no! You've decided that you don't want the extra set of fancy lights on the bumper.

In the past, if you tried to delete those lights directly from the Prefab instance in the scene, you couldn't. You had to go back to the Prefab Asset, delete it there, and then reapply it to the instance. Not ideal, right?

But, with the updates in Unity 2022.2, you can now delete GameObjects directly from a Prefab instance in the Scene view. Just select the GameObject you don't want anymore, hit the delete key, and voilà! It's gone. ✨

This is especially useful when you're using Prefabs as a starting point and then want to customize them for certain situations.

Remember, though, deleting a GameObject from a Prefab instance creates an override, meaning that change won't affect the original Prefab Asset or other instances of it. Only this instance will be without the fancy lights. So, feel free to make your Prefab instances unique! 🎨

Now, isn't that a game-changer? Unity continues to refine workflows, making the development process smoother and more intuitive!

Alright! Let's dive into the Prefab Family pop-up. 🎈

You're working with Unity and using Prefabs, right? And you might be using nested Prefabs, where you have Prefabs inside other Prefabs. It can get a little bit... messy, to say the least. 😅

Now, when you select a GameObject in a nested Prefab instance, a little pop-up appears above the Inspector. Click on it, and boom!

💥 You're greeted with a neat visualization of your Prefab’s hierarchy. This 'family tree' allows you to see exactly where you are in the hierarchy, and you can easily navigate to other parts of the Prefab by clicking on the elements in the pop-up.

This way, you can clearly see the relationship between your Prefabs and their instances, saving you from the nesting nightmares. 😴So, take advantage of this pop-up and make navigating your Prefabs a breeze!

Okay, now let's chat about the Unused Overrides drop-down.

Picture this: you're knee-deep into tweaking a Prefab instance when you spot a change listed in the Overrides drop-down that you don't recall making. 🤔What's up with that, right? Well, that's where the Unused Overrides feature comes into play. 🕹️

Starting with Unity 2022.2, there's an additional Unused Overrides drop-down available. This little buddy lists changes you've made to a Prefab instance that don't affect its current behavior. Think of it like a gentle reminder that you may have tweaked something you didn't need to.

But, the fun doesn't stop there! By right-clicking an unused override, you can choose to either apply it (making it part of the Prefab Asset), revert it (going back to the Prefab Asset's value), or delete it (removing the override without changing the Prefab Asset's value).

Alright, we're at the finish line! 🏁

Just like those handy-dandy Lego blocks, Unity's Prefabs are a cornerstone in building your game, no matter how simple or complex it is.

🏗️ From creating reusable components, adjusting instances, managing Prefab variants, to overriding Prefab values, these tools give you flexibility, efficiency, and control, making your game development a breeze.

So why not try to mix things up? Play with Prefabs, create some wild combinations, or invent efficient systems - the limit is your imagination! ✨

Marco Mignano 👋 ➡️ Passionate Unity Game Developer Marco - coding aficionado, video game enthusiast, and self-proclaimed piazza addict. Constantly conquering new challenges, one line of code at a time. Got an exciting project? Let's make your game next game together!

Contact: marco@gladiogames.com