Unreal vs. Unity: Actors & Components, Inheritance & Composition

Unreal, Unity, and Godot have some similar design patterns, but there are a few things that set UE4 apart. We'll look at the range of Actor and ActorComponent classes available in Unreal, and we'll explore a few different ways to put them together.

00:00 - Introduction
00:48 - Basic game object construction in Unity, Godot, Unreal
02:51 - Common concepts: Game World, Game Object, Component
03:33 - Components in Unreal: UActorComponent, USceneComponent, UPrimitiveComponent
05:36 - Game objects in Unreal: AActor
06:20 - Actor history: monolithic actors in UE2, component refactor in UE3
06:53 - Actor inheritance and subtyping, in addition to ActorComponent inheritance
07:40 - When to use Actor vs ActorComponent
08:18 - Example: First-person interaction via base class, interface, or component
10:27 - The case for plain old Objects
12:07 - Conclusion

#UnrealEngine #UE4 #programming

[mana]

How do you only have 3k subs? This is better quality than most paid courses

[anthonyapm]

Where did you go man? Best tutorials on the tuubs.

[greyly_]

I've been coding for 38 years and last week I decided it was time to learn a game engine. Unity's C# API was immediately obvious to me and felt clean. My initial impression of UE4 was that it's a mess, struggling under the weight of layers of legacy. I'm happy to have found someone making videos about these things that seems to be an actual experienced developer and who can set me straight.

[AlexForsythe]

Quick correction: in the DefaultGame.ini snippet shown at 11:52, the object path should read:

Also note that the reason for UInteractionTrace being a class is that it encapsulates both data and functionality - if we just wanted to run a simple line trace and we didn't care about debug drawing or having a configurable distance, then it'd make sense to just call directly in our Pawn's tick function.

In cases where you have a complicated bit of functionality (but no accompanying state) that you want to factor into a reusable form, then a plain old function is often the way to go.

[uzizizu]

you should apply for Unreal Grant, they give money for people who teaches their engine and you are a GOD in teaching

[TheLolilol]

This video is incredible. Every single frame is spring-loaded with accessible, useful information. It takes <14 minutes to show HOW and why, and that's including establishing parallels to the structure of other game engines AND also showing the exact implementations WITH code and showing relevant example footage when making comparisons.

I find myself saving snapshot after snapshot because of the sleek presentation of what would otherwise appear to be complex constructs with incredible clarity.

[shreyas]

I can't believe that you only have 5k subs!! Your production quality is better than most of the tutorials on youtube.

[mariosbikosvideos]

Damn I really want Alex to come back and do more videos like this one. The video visualisations are amazing!

[Zamaroht]

As a developer with 7 years of experience in Unity who has never used Unreal before, this was really insightful, thank you. I found myself pausing the video every few seconds to digest the examples and concise information, or to play around a bit in the editor. Everything was really well explained and clear, thank you! It's definitely a bit of a paradigm shift

[rahdanger]

You are the fuckin best teacher I have ever seen I still need and don’t fully understand everything yet, but this video has just given me the biggest learning leap yet, thank you sir I absolutely mean that thank you thank you and don’t ever stop

[nikhilraktale]

Freaking finally ... Thanks for explaining the dual hierarchies !

[kiaranr]

Brilliant, clear explanations of a complex topic. Coming from Unity to Unreal, it took me a very long time to piece together a mental mapping of how their architectures relate. Looking forward to your next video! This may be the channel that finally convinces me to use Patreon.

[beanboy]

Absolutely without a doubt the best videos on Unreal Engine, please keep creating. I know how much work the fancy animations can be, especially is bulky software like After Effects, but they are SO worth it! That hierarchy graph cleared up so much confusion for me about the Actor hierarchy in unreal. This explains how even though Unreal uses a composition approach it always seemed so different than Unity or Godot!

[teac]

This is a very helpful 30, 000 ft view of the architecture hierarchy. And props for front-running typical programmer questions of 'can we just use...'

[FarazKhan-lgul]

Amazing video! the visualization is easily getting the point across. It’s surprising that unreal tutorials are missing basic vids like engine breakdown. Alex this makes your video really valuable especially for beginners. Keep up the good work!

[owencoopersfx]

This is seriously an excellent video. I work both with Unity and Unreal, and this is a great explanation of the differences between them.

[GWithTheFlw]

Amazing video Alex! Very well done. Thank you for making it.

[nickcy]

This is amazing, the best video I've seen that goes into the different popular engines' approaches and their differences. Thank you so much!

[ArtVandelayInc]

Flawless... You're so good at this

[QuackTeamJames]

Very interesting video :D Now I want to play around in Unreal when I get the chance to see what I can come up with using the blueprints and actors. Looking forward to the next one! Thanks for all your hard work Alex.