How to delete Unity Hybrid ECS Entities?

Question

I'm trying to get into Unity's Hybrid ECS feature. Creating and Manipulating Entities has worked fine so far for me, but somehow I can't find a viable option to delete Entities which works 100% of the time without errors.

I know about object pooling, however in this particular case there is no way around deleting Entities.

Thank you in advance!

Answer 1

Coming from an Entitas background here, i usually:

1. Create a component called Destroy.

2. at the end of the execution cycle i have a Cleanup System that reacts for entities that have the Destroy component and Destroy them, i also check if they have a View component so i can destroy the attached GameObject. usually Entitas does the magic with pooling.

   public class EntityDestroySystem: ICleanupSystem
   {
       private Contexts _contexts;
   
       private IGroup<RenderEntity> _renderGroup;
       private IGroup<GameEntity> _gameGroup;
   
       public EntityDisposeSystem(Contexts contexts)
       {
           _contexts = contexts;
   
           _renderGroup = _contexts.render.GetGroup(RenderMatcher.AllOf(RenderMatcher.Destroy));
           _gameGroup= _contexts.game.GetGroup(GameMatcher.AllOf(GameMatcher.Destroy));
       }
   
       public void Cleanup()
       {
           foreach (var e in _renderGroup.GetEntities())
           {
   
               e.Destroy();
           }
   
           foreach (var e in _gameGroup.GetEntities())
           {
               e.Destroy();
           }
       }
   }