Entities outside SystemBase

Questions & Answers
1

Is it possible to list the entities I need with components via ForEachLambdaJobDescription Entities without the SystemBase class?

Let’s say there is some event that enumerates entities only once in a lifetime, and calling onUpdate SystemBase every time sounds somehow too cumbersome.

2

Yes. You can query and grab whatever data you need, even from a common MonoBehaviour.

But be aware that everything Unity.Collections ( NativeArray<T> etc) will be slow to read/write outside a job. So still prefer jobs where possible (you can start them from Monobehaviours too)

void Start ()
{
	var world = World.DefaultGameObjectInjectionWorld;
	var entityManager = world.EntityManager;

	var query = entityManager.CreateEntityQuery(
		typeof(RenderBounds)
	);
	
	NativeArray<Entity> entities = query.ToEntityArray( Allocator.Temp );
	Entity[] entitiesArray = entities.ToArray();
	
	NativeArray<Entity> renderBounds = query.ToComponentDataArray<RenderBounds>( Allocator.Temp );
    RenderBounds[] renderBoundsArray = renderBounds.ToArray();
}