# Intro to Unity ECS
## What you'll develop in this ECS section
Github branch link:
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[Join our Discord for more info](https://discord.com/invite/88j758eUvs)
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### Functionalities included
* Sub Scenes and conversions
* Setting components and variables during conversion
* Using EntityManager to make structural changes
* Using command buffers to make structural entity changes
* Setting up command buffers to run parallel jobs with CreateCommandBuffer().AsParallelWriter()
* Adding, setting, and removing components
* Generating authoring components and IConvertGameObjectToEntity interfaces
* Entity queries and .ForEach()
* Setting local variables for entity queries
* Scheduling a job with .Schedule()
* Scheduling a parallel job with .ScheduleParallel()
* Running on the main thread with .Run()
* Combining job handles with JobHandle.CombineDependencies()
* Create and destroy entities programmatically
* Create and move entities based on user input
* Create an entity from a prefab
* Adding cameras to entities
* Hybrid ECS
* New Build Configuration system
* Creating a base shared configuration
* Sub-second "play" start
## Entity Component System (ECS)
If you can spare **32 minutes** listen to [Far North Entertainment](https://www.youtube.com/watch?v=yTGhg905SCs) explain Unity's ECS and their hybrid approach **(A MUST-WATCH IF HAVE NEVER WORKED WITH ECS)**
If you can spare **64 minutes** listen to Blizzard's [Timothy Ford](https://www.youtube.com/watch?v=W3aieHjyNvw) explain general concepts in ECS (Not Unity-specific ECS, actually Blizzard's own game engine, but the architectural concepts are the same) **<-- ESPECIALLY RECOMMENDED FOR NETCODE**
If you can spare **42 minutes** listen to Unity's 5-part series overview of ECS: [Part 1](https://www.youtube.com/watch?v=WLfhUKp2gag), [Part 2](https://www.youtube.com/watch?v=z9WE3fwre-k), [Part 3](https://www.youtube.com/watch?v=WZ6-LxwxWEI), [Part 4](https://www.youtube.com/watch?v=j2z5KRWZTDA\&t=1s). [Part 5](https://www.youtube.com/watch?v=D1KShj8ZV_I) for more explanations of ECS
If you can spare **23 minutes** listen to [Code Monkey](https://www.youtube.com/watch?v=ILfUuBLfzGI) explain ECS
If you can spare **9 minutes** listen to [Brackeys](< https://www.youtube.com/watch?v=_U9wRgQyy6s>) (RIP 💀) explain ECS
...and if you can spare **0 minutes** to understand ECS:
### **😃**☯ **Learning Unity ECS will be worth it! Look at these performance gains:**
### 😳 ☯ Unity ECS will be painful at times (costs of ECS):
Sure, ECS is exciting, but from the Forum threads we linked to above, you can see that there is plenty of complexity that needs to be managed.
Learning a functional programming paradigm can be difficult. Shifting out of a OOP mindset dominance can be difficult, too. ECS demands both, to some degree.
Luckily, Unity's current ECS architecture is actually a hybrid (of both Monobehaviour and ECS), which eases you into the data-oriented paradigm if you are totally new to it.
### Unity resources
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Read the high-level overview of how Unity thinks about and implements ECS: \
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Read through the explanation of Unity Editor's ECS-specific windows\
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Unity documentation for Unity.Entities 0.50.1-preview\.2: . **Refer to this for more information.**
Unity forums for DOTS: . **Pretty responsive to questions.**
Unity samples for ECS: . **More in-depth and complicated examples.**
Big brain discussion on ECS vs. GameObjects: . **If you are a bit more hardcore.**
### **To be best prepared for the code-alongs**
* [ ] Watch an ECS explanation video(s)
* [ ] Read through Unity's high-level overview
* [ ] Read through Unity's "Entity Debugger" explanation
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[Join our Discord for more info](https://discord.com/invite/88j758eUvs)
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