How to create system group with new APIs?

Unity Engine
,
1

World.Active.GetOrCreateSystem() is depreciated.

Thanks.

2

its just World.GetOrCreateSystem if you mean systems.

1 Like
3

I’m using it from MonoBehvaiour so I’m not sure if I can use World

void FixedUpdate()
{
group = World.Active.GetOrCreateSystem();
group.Update();
}
I am not getting any compilation errors but there is a null reference exception when assigning group

4

for accessing within monobehaviours use
World.DefaultGameObjectInjectionWorld.GetOrCreateSystem (“Active” was so much simpler but apparently misused and not the correct context of active in most cases)

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5

Thanks!

6

Unfortunately I still receive a null reference exception when using the new API.

7

Are you using a custom bootstrap? If so you’ll need to set world yourself.

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8

Thanks for your response! It’s been a while since I’ve worked on this so I’m not sure if what I’m doing is a bootstrap method or not.

I just have

[DisableAutoCreation]
public class ExampleSystemGroup : ComponentSystemGroup {}

void FixedUpdate()
    {
        //group = World.Active.GetOrCreateManager<ExampleSystemGroup>();
        group = World.DefaultGameObjectInjectionWorld.GetOrCreateSystem<ExampleSystemGroup>();
        group.Update();
    }

For some reason group = World.DefaultGameObjectInjectionWorld.GetOrCreateSystem();results in NullReferenceException

Thanks a lot for your help!

9

How is this done?

10

Have you set the define UNITY_DISABLE_AUTOMATIC_SYSTEM_BOOTSTRAP or have you implemented ICustomBootstrap

DefaultGameObjectInjectionWorld is set in DefaultWorldInitialization

        public static void Initialize(string defaultWorldName, bool editorWorld)
        {
            RegisterUnloadOrPlayModeChangeShutdown();

            if (!editorWorld)
            {
                var bootStrap = CreateBootStrap();
                if (bootStrap != null && bootStrap.Initialize(defaultWorldName))
                    return;
            }

            var world = new World(defaultWorldName);
            World.DefaultGameObjectInjectionWorld = world;

So this won’t be called if you either disable auto bootstrap or your custom bootstrap returns true, in which case you should be setting it yourself.

1 Like