How do you create multiple worlds?

Hello,

I'm curious how to go about creating different worlds within a scene, and how to control which systems are associated with which worlds. The section about default world creation has two dead links.

https://github.com/Unity-Technologi...master/Documentation/content/ecs_in_detail.md

Thanks in advance! -Kevin

 

https://forum.unity.com/threads/i-c...o-help-explain-unity-ecs.524711/#post-3448354

 

Note that by mimicking DefaultWorldInstantiation you would not be able to do :

1. // Register hybrid injection hooks
2. InjectionHookSupport.RegisterHook(new GameObjectArrayInjectionHook());
3. InjectionHookSupport.RegisterHook(new TransformAccessArrayInjectionHook());
4. InjectionHookSupport.RegisterHook(new ComponentArrayInjectionHook());

As all of those 3 custom hooks are private class. If you still have a default world instantiation then fine, but if you also disable that too you lose an ability to inject components, inject game objects, and inject transform access.

 

In the long term I hope they have a way to create multiple worlds programmatically, making things magic is always very frustrating and limiting.

 

Thanks for this, I'll take a look.

 

Wish I could upvote this a hundred times.

 

Had similar issue and can solve via reflection

https://forum.unity.com/threads/solved-cant-inject-componentarray-injectcomponentgroup-cs.551575/

Code (CSharp):

1. Assembly unityEntitiesAssembly = Assembly.Load("Unity.Entities.Hybrid, Version=0.0.0.0");
2. Type hookType;
3. hookType = unityEntitiesAssembly.GetType("Unity.Entities.GameObjectArrayInjectionHook");
4. InjectionHookSupport.RegisterHook(Activator.CreateInstance(hookType) as InjectionHook);
5. hookType = unityEntitiesAssembly.GetType("Unity.Entities.TransformAccessArrayInjectionHook");
6. InjectionHookSupport.RegisterHook(Activator.CreateInstance(hookType) as InjectionHook);
7. hookType = unityEntitiesAssembly.GetType("Unity.Entities.ComponentArrayInjectionHook");
8. InjectionHookSupport.RegisterHook(Activator.CreateInstance(hookType) as InjectionHook);

 

Do you know where these are used? Specifically the ComponentArrayInjection. I'm using a custom world but never added these lines and I have no obvious missing "features". [Inject] is working fine so what is this for?

 

If you use your world with default world it works fine.

 

What classifies as default world? Using the default bootstrapper?
I'm using [DisableAutoCreation] in all the systems, pretty much like:
https://github.com/Unity-Technologies/FPSSample/blob/master/Assets/Scripts/Game/Entity/GameWorld.cs
They use a new World() and the Injection part later. Is the injectionhook set in the world constructor now?
What's weirding me out is that I have the InjectionHook commented out and ComponentArrays in systems still work. So what does it do?

Also, FPSSample uses TransformAccessArray but has the injection commented out.

 

Default world is default world created by ECS for editor/play modes, it creates always, untill you not disable it by declaring UNITY_DISABLE_AUTOMATIC_SYSTEM_BOOTSTRAP