Enabling and Disabling Systems for Unity ECS

Is there a way to enable and disable individual systems programmatically for Unity ECS?

 

Yes, systems, so ScriptBehaviourManagers have property "Enabled"

EDIT: In newer version Enabled property is from ComponentSystemBase

 

Do you have a more complete example of how to do this?

 

Code (CSharp):

1. public class ComponentSys : ComponentSystem
2. {
3.     [Inject] private SomeSystem someSystem;
4.  
5.     protected override void OnUpdate()
6.     {
7.         if (disableSomeSystem)
8.             someSystem.Enabled = false;
9.     }
10. }

or

Code (CSharp):

1. public class SomeClass : MonoBehaviour
2. {
3.     private void SomeMethod()
4.     {
5.         World.Active.GetExistingManager<SomeSystem>().Enabled = false;
6.     }
7. }

 

I see, awesome. I didn't know the system would be the type of the `GetExistingManager` call.

 

can you disable a system precompiled? So it is not even in the game?

 

Hmm - I think at that point you may not even want to create the System automatically using the [DisableAutoCreation] attribute on the system.

If you need later you can always create the system into the world.

 

ty this is what I was looking for

 

Another option... use a disable tag in your SystemBase derived class like this:

Code (CSharp):

1. Entities.WithAll<DisableTag>(....).Foreach(() => { .... });

And then when you want to disable it:

Code (CSharp):

1.  
2. private void ToggleMyComponent(in EntityManager em, in Entity entity, bool enable)
3. {
4.     if (enable) {
5.         if (em.HasComponent<DisableTag>(entity)) { em.RemoveComponent<DisableTag>(entity); }
6.     } else {
7.         if (!em.HasComponent<DisableTag>(entity)) { em.AddComponent<DisableTag>(entity); }
8.     }
9. }

(you could replace em with EntityCommandBuffer.ParallelWriter ecb if you're toggling within a parallelized job).

The system scheduler is smart enough to know that if nothing matches the query in the SystemBase, the Update() function won't get called at all.

 

For Unity 2019.4.28f1 with HybridRenderer 0.5.2-preview 4 i used this to toggle the MeshRendererV2:

Code (CSharp):

1. World.DefaultGameObjectInjectionWorld.GetExistingSystem<Unity.Rendering.RenderMeshSystemV2>().Enabled

I put it inside a monobehaviour class for a UI button and it correctly toggles the renderer on and off.

 

strange I don't have public property Enabled for the system

 

The method is returning a SystemHandle. You need to resolve that to a SystemState ref.