| Parameter | Description |
|---|---|
| query | A query that must match entities this frame in order for this system to run. |
Adds a query that must return entities for the system to run. You can add multiple required queries to a system; all of them must match at least one entity for the system to run.
Any queries added through RequireForUpdate override all other queries cached by this system.
In other words, if any required query does not find matching entities, the update is skipped even
if another query created for the system (either explicitly or implicitly) does match entities and
vice versa.
Note that for components that implement IEnableableComponent
this method ignores whether the component is enabled or not, it only checks whether it exists.
It also ignores any other filters placed
Additional resources: SystemState.ShouldRunSystem, SystemState.RequireForUpdate, RequireMatchingQueriesForUpdateAttribute
Require that a specific component exist for this system to run. Also includes any components added to a system. See SystemHandle for more info on that.
Any queries added through RequireForUpdate override all other queries cached by this system.
In other words, if any required query does not find matching entities, the update is skipped even
if another query created for the system (either explicitly or implicitly) does match entities and
vice versa.
Note that for components that implement IEnableableComponent
this method ignores whether the component is enabled or not, it only checks whether it exists.
Additional resources: SystemState.ShouldRunSystem, SystemState.RequireForUpdate, RequireMatchingQueriesForUpdateAttribute