How to Use SYSTEMS in Unity ECS 1.0 - Unity DOTS Tutorial

👨‍💻 Code/Scripts from this video: www.tmg.dev/1-0-Systems-Code 👨‍💻
💬 Come chat with other DOTS/ECS devs: tmg.dev/Discord 💬
📌 Watch my intro to DOTS 1.0 step-by-step tutorial video: • Unity ECS 1.0 Full Pro... 📌
🚧 Resources Mentioned 🚧
- Unity ECS 1.0 Tutorial Video: • Unity ECS 1.0 Full Pro...
- System Update Order Video: • Managing System Update...
- System State Component Video: • System State Component...
💻 My Game Development Setup: tmg.dev/GameDevPC 💻
📸 My Camera Gear: tmg.dev/CameraGear 📸
🎮 Let me know what other topics you want to learn about 🎮
⌚ Time stamps for key topics ⌚
- 0:00 - Systems in ECS 1.0
- 1:30 - Systems FAQ
- 6:56 - Project Overview
- 7:38 - Create a new SystemBase
- 10:21 - Using the System Entity
- 13:06 - Creating an ISystem
- 15:21 - What is the SystemState?
- 17:36 - What is the SystemAPI?
- 21:32 - System Code Generation
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👨‍💻 GitHub: github.com/JohnnyTurbo
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#️⃣ #UnityDOTS #UnityECS #MadeWithUnity

[@nyscersul42]

Again, great precision, great adherence to what is relevant in your chosen topic. Very clear. :)

[@WAYNGames]

ISystem can access managed data component through the SystemAPI. But they can't be bursted in that case.

[@TurboMakesGames]

Good catch - thanks for keeping me on point!!

[@YO0oNas]

Nice video, I came back to it regularly while upgrading my codebase to 1.0 !

[@TurboMakesGames]

Right on! How did the upgrade process go for you?

[@YO0oNas]

@@TurboMakesGames It was quite a lot of work, The API changes & new concepts improve DOTS & ECS. But I hope the API doesn't change this much anymore after 1.0 releases. The largest change that I had to make was modifying my conversion code to the baking process now. Moving back to IJobChunk from IJobEntityBatch was a bit annoying since I used to only have IJobChunk! And the upgrade is still not completely done, there's still some work to make the codebase follow the new concepts in 1.0.

[@davtam]

Thanks for the awesome content! You are able to explain these up-to-date features very clearly and concisely.

[@TurboMakesGames]

Hey Dav, thank you so much for the support and the kind words 😊

[@CLOmorokko]

動画を作ってくれてありがとう。いつも参考にしてます。DOTSは素晴らしいシステムです

[@TurboMakesGames]

So glad to hear you've been enjoying DOTS and these videos. All the best!!

[@xuananlai8932]

Greate video, thank you for your instruction to the ECS, please keep going with more contents

[@TurboMakesGames]

Many more on the way! Glad these have been helpful 😀

[@Heero5308]

awesome thank you!

[@Victor_Js]

After years waiting for the Unity ECS, I finally went on a new project to the Bevy Engine ECS, and I don't regret it, a pleasure to program in Rust, and the unsurpassed performance, all solid, finally I feel the consistent development.

[@TurboMakesGames]

Good to know you've been having such a good experience so far!

[@tkg__]

It's great until you have to do anything that needs animation, audio, level building or _most other stuff_. I have high hopes for Bevy but it needs a few more years in the oven. Also, after benchmarking Bevy vs Unity on sheer FPS when rendering hundreds of meshes - Unity wins. At least for now.

[@_ironrose]

i would rather use c++ ecs library or unity dots ecs instead of bevy(rust). It looks unstable to me

[@tkg__]

@@_ironrose because it is. The API changes between releases very rapidly.

[@adamodimattia]

I did so too, however Bevy as of right now is in no shape to let you make top notch product, it changes and evolves rapidly. Of course it gives a lot of pleasure when working with, mainly because of Rust, but for myself as of right now it is more of part time hobby, something for the soul. However at this point I would not try any of c++ ecs libraries, good bye c++ and welcome Rust, I only use c++ when I have no other choice :) I am not sure if I am gonna dive into Unity ecs any time soon, but I really like this channel, a lot of Johnny's content is quite universal to ecs in general. Keep it up Johnny!

[@simulation3120]

Bless you.

[@anatoliy9696]

Thanks a lot ! Will there be a lesson on how to run unit tests at DOTS or what do they use?

[@TurboMakesGames]

If there is interest in the topic, I think it could be a good one to cover - good to know you'd be interested!!

[@ryanputh1118]

I would also be interested in this.

[@Krakkk]

I don't get why u need to get the first system in the second one. Aren't component data updated already? Why u can't just get component and read the data from there?

[@user-uj8lt5kh2k]

So the point is that your ISystem struct needs of referenceType SystemBase (that's why it's updateAfter) in order to Get Input as MonoB and transform as ECS. Is it really so good? U combine two worlds in order to move your zombie, but is it really the best practice in order to get best "usage" of ECS?

[@MechabitGames]

awesome video

[@TurboMakesGames]

Thanks, glad you thought so!!

[@kailiyu]

I want to learn about how to use baking workflow to load a prefab from a assetbundle and then convert it to entity at runtime.

[@TurboMakesGames]

Awesome, that is a great suggestion. Wonder if this could be accomplished through a custom baking system

[@Traiden_]

It is really weird, the orange dot isn't showing on the Entities Hierarchy in my editor. I think everything is the same though. Great videos by the way, I've been doing stuff with ECS since wayyyyy back in 0.4. It has come along way and these are great for getting me up to speed.

[@TurboMakesGames]

Hmm, yeah that should be fine. Yeah ECS has definitely came a long way since then! Glad these have been helpful 😊

[@Traiden_]

@@TurboMakesGames I tried an earlier version and the orange dot was there, I wonder if they changed it for 22.0b16.

[@nguyenhoaiphucnguyen3334]

Cảm ơn bạn!

[@TurboMakesGames]

Thank you so much for the support Nguyen!!

[@nguyenhoaiphucnguyen3334]

Tks.

[@TurboMakesGames]

Sure thing!!

[@happyfish9692]

Does ECS 1.0 support animations/animator or animation instancing?

[@bartubas1958]

Hi Turbo, is the Unity Netcode usable now (at least for prototyping). I'd like to just be able to connect 2 local computers and make a small game. Have you tried it out?

[@TurboMakesGames]

Unity's netcode for Entities is certainly usable. Just be aware that it is a bit more on the experimental side and you have to do a few tricks to get things to work right. Also note that it is not yet compatible with the new translation system. Other than that it is plenty fine to experiment around with and make a small game

[@superpatrick8902]

i'm having error on code "_inputSystemHandle = state.World.GetExistingSystem();" Burst error BC1016: The managed function `Unity.Entities.SystemState.get_World(Unity.Entities.SystemState* this)` is not supported i can execute the project but error keeps comming out. what am i missing??

[@voanhnguyenduy7302]

i have the same error

[@songerk7102]

I have the same error, did you find any solution ?

[@qw1ntwhyu701]

Hi, tell me how to interact with 2D animation?

[@KonradGM]

So generally SystemBase should be used if my project is a mix of game object and entities? (let's say player is Mono object, but enemies are entities?) While Isystem should be used if i'm relying entirely on entities?

[@TurboMakesGames]

Both SystemBase and ISystem can be used in any ECS project. The difference is you'll need to use SystemBase if you want to use any managed types in that particular system.

[@KonradGM]

@@TurboMakesGames OK i see, i have small trouble between distinguishing what is managed and not managed system. I assume it depends on data used for the components?

[@stefan429]

it looks so similar to the current MB component system. can you drag and drop scripts onto systems like the normal workflow instead of adding it in code in OnCreate? really strange if you cant imo

[@TurboMakesGames]

Nope, unfortunately there isn't (yet) a way to set system data through the inspector

[@yiboliang8338]

Is there a way to pass NativeMultiHashmap from one system to another? It is imposible to attach this native container onto IComponentData. And If I set the native container to a static field then burst won't compile it. :(

[@yiboliang8338]

Also, Looking forward a ECS 1.0 physics tutorial :)

[@TurboMakesGames]

I have not used the NativeMultiHashmap in a component form yet, but after playing around native containers on IComponentDatas, they seem to be a bit finnicky, so I'd like to explore these a bit more to figure out their limitations. Will definitely be making a 1.0 Physics tutorial, just won't start until it is fully compatible with the new translation system.

[@v037_]

bro can you say to us where you learnt all this stuff?

[@lorenzocgt1021]

I noticed that when i try to use foreach inside the ISystem OnCreate method, it doesnt do anything

[@TurboMakesGames]

Most likely that is because when the OnCreate method runs, it does so before the entities you are querying for don't exist yet, so it basically just skips the foreach loop

[@adamodimattia]

I am not sure if I understood correctly, "system are also now an entity and they can store data" - how is it more in line with ecs? Aren't systems supposed to not contain data?

[@movi91]

Systems are not an entity, they have an entity associated with them, that you can use conveniently to store data related to it

[@adamodimattia]

@@movi91 seems weird, why would a system need a data of its own? Maybe do modify how it's running?

[@danielkandersen6599]

@@adamodimattia it enables you to know the exact life time. As it is there from OnCreate till directly after OnDestroy. Meaning you could contain entire collections on a component which you added to the system. And then dispose the memory before getting rid of the entity

[@yudnai5577]

I hope they will simplify it like monobehaviour

[@hunterduck1274]

What is a world and how is it useful?

[@tkg__]

World contains your entities. Usually you'll have one world, but you can create more. For example the ECS networking package uses separate Worlds for each client and the server.

[@hunterduck1274]

​@@tkg__ Thanks you! I understand what it is now. Once again I was overthinking it.

[@DraconicBovine]

This video isn't accurate anymore. They discourage the use of SystemBase. ISystem can now use both managed and unmanaged types (if you use managed ones it can't be burst compiled of course) Got that information from the dots fundamentals course in part 3.1 under Debugging Entities

[@TurboMakesGames]

Yeah that was a mistake on my part. Though typically whenever I use managed types I use a SystemBase as a way to kind of indicate that I am using managed types somewhere in that system.

[@DraconicBovine]

@@TurboMakesGames I did see a forum thread recently about it and it seemed like ISystem was more performant than SystemBase by default as well. I have opted to just reflect that in the system names instead for my purposes

[@mad_t]

ISystem is NOT a struct! ;-) It's an interface with methods that can be burst compiled. No one can stop you from creating a class using managed data and implementing ISystem interface methods. You just can't use managed data in those methods. It's not DOD but it's not prohibited, it's just stupid. :-)

[@TurboMakesGames]

Fair enough 😆😆

[@justlama0]

thanks for the video! I wonder if Unitechs is trying to do small projects themselves and use this? do they consult with developers about the usability of the API? the innovations in 1.0 are just awful... the entity attached to the system is a terrible anti-pattern.

[@TurboMakesGames]

They definitely have close relationships with developers who've built out larger projects and they read all the forum posts. I've been quite happy with all the additions in 1.0 - why do you think the system entity is such a bad idea?

[@Fightitinside]

I also don't understand why you would want to have an entity attached to a system. You have to directly reference a system anyway, so it's almost the same thing as just having a public field in this system. Systems should not know where the data comes from