bool True if the system should be updated, or false if not.
Reports whether this system satisfies the criteria to update. This function is used internally to determine whether the system's OnUpdate function can be skipped.
By default, systems will invoke OnUpdate every frame.
If a system calls SystemState.RequireForUpdate or SystemState.RequireForUpdate
in OnCreate, it will only update if all of its required components exist and
required queries match existing chunks. This check uses [IsEmptyIgnoreFilter], so the queries may
still be empty if they use filters or [Enableable Components].
If a system has the RequireMatchingQueriesForUpdateAttribute it will
update if any EntityQuery it uses match existing chunks. This check also uses [IsEmptyIgnoreFilter],
so all queries may still be empty if they use filters or [Enableable Components].
Note: Other factors might prevent a system from updating, even if this method returns
true. For example, a system will not be updated if its [Enabled] property is false.
[IsEmptyIgnoreFilter]: xref:Unity.Entities.EntityQuery.IsEmptyIgnoreFilter
[Enableable Components]: xref:Unity.Entities.IEnableableComponent
[Enabled]: xref:Unity.Entities.SystemState.Enabled