Feedback Getting spatial queries working and making them efficient

I have a large collection of entities that exist in a Physics World, and I would like to apply a force to a group of them that are within a specific area.
For context, in a classic monobehavior I would do something like this:

Code (CSharp):

1.        
2.     ContactFilter2D filter = new ContactFilter2D();
3.     filter.SetLayerMask(LayerMask.GetMask("Enemies"));
4.     List<Collider2D> hits = new List<Collider2D>();
5.     Physics2D.OverlapCircle(rb.transform.position, explosionRadius, filter, hits);
6.  

I would like to achieve something similar in DOTS. I have read through the docs on spatial queries and am struggling to understand the implementation of the provided examples, I'm not sure where this code would exist, and what I should do with the returned rigidBodies. My current attempt is to create a SystemBase that handles everything, but aside from it just straight up not working, I'm also unsure if this will be efficient and if this code should exist in a Job somehow. Here's my existing code:

(In the onUpdate method of a SystemBase class)

Code (CSharp):

1.  
2.         var physicsWorldSystem = World.DefaultGameObjectInjectionWorld.GetExistingSystem<Unity.Physics.Systems.BuildPhysicsWorld>();
3.         var collisionWorld = world.CollisionWorld;
4.         NativeList<int> hitsIndices = new NativeList<int>(Allocator.Temp);
5.  
6.         CollisionFilter filter = new CollisionFilter
7.         {
8.             BelongsTo = ~0u,
9.             CollidesWith = ~0u,
10.             GroupIndex = 0
11.         };
12.         //Check for nearby unitsgroup already existing
13.         Aabb aabb = new Aabb
14.         {
15.             Min = center + new float3(-radius, 0, -radius),
16.             Max = center + new float3(radius, 1, radius)
17.         };
18.         OverlapAabbInput overlapAabbInput = new OverlapAabbInput
19.         {
20.             Aabb = aabb,
21.             Filter = filter,
22.         };
23.  
24.         bool haveHits = collisionWorld.OverlapAabb(overlapAabbInput, ref hitsIndices);
25.         var bodies = collisionWorld.Bodies;
26.  
27.         for (int i = 0; i < hitsIndices.Length; i++)
28.         {
29.             int rigidBodyIndex = hitsIndices[i];
30.             RigidBody rigidBody = bodies[rigidBodyIndex];
31.             PhysicsWorldExtensions.ApplyLinearImpulse(world, rigidBodyIndex, new float3(1, 1, 0) * 500);
32.         }
33.  

The overlapAABB seems to work, I'm getting a list of RigiBodyIndex's, however no matter how I create my float3 Impulse everything is refusing to move.

So my questions are:
- Is there an obvious reason why ApplyLinearImpulse isn't working here?
- Is this the best approach?
- If it makes more sense that this be run in a Job (or if the movement/impulse should be in a job) how can I use a JobQuery or something similar to ensure the Job only runs on the discovered RigidBodies?

 

So I got it working, I think it was my CollisionFilter, not certain, here's my updated code. Note: the AABB is a thin rectangular prism oriented for a 2D environment.

Code (CSharp):

1.     protected override void OnUpdate()
2.     {
3.         int radius = 10;
4.         for (;explosions > 0; explosions--)
5.         {
6.             var location = playerQuery.ToComponentDataArray<Translation>(Allocator.Temp);
7.             if(location.Length > 0)
8.             {
9.                 var physicsWorldSystem = World.DefaultGameObjectInjectionWorld.GetExistingSystem<Unity.Physics.Systems.BuildPhysicsWorld>();
10.  
11.                 /*                PushAwayFromPointJob moveJob = new PushAwayFromPointJob { dt = Time.DeltaTime, center = location[0].Value, force = 500, radius = 10, world = physicsWorldSystem.PhysicsWorld };
12.                                 moveJob.Schedule(entityQuery);*/
13.  
14.                 var collisionWorld = physicsWorldSystem.PhysicsWorld.CollisionWorld;
15.                 var world = physicsWorldSystem.PhysicsWorld;
16.                 NativeList<int> hitsIndices = new NativeList<int>(Allocator.Temp);
17.  
18.                 CollisionFilter filter = new CollisionFilter
19.                 {
20.                     BelongsTo = 1 << 1,
21.                     CollidesWith = 1 << 0,
22.                     GroupIndex = 0
23.                 };
24.                 //Check for nearby unitsgroup already existing
25.                 Aabb aabb = new Aabb
26.                 {
27.                     Min = location[0].Value + new float3(-radius, -radius, -1),
28.                     Max = location[0].Value + new float3(radius, radius, 1)
29.                 };
30.                 OverlapAabbInput overlapAabbInput = new OverlapAabbInput
31.                 {
32.                     Aabb = aabb,
33.                     Filter = filter,
34.                 };
35.  
36.                 collisionWorld.OverlapAabb(overlapAabbInput, ref hitsIndices);
37.                 var bodies = collisionWorld.Bodies;
38.                 var sqrRadius = radius * radius;
39.  
40.                 for (int i = 0; i < hitsIndices.Length; i++)
41.                 {
42.                     int rigidBodyIndex = hitsIndices[i];
43.                     RigidBody rigidBody = bodies[rigidBodyIndex];
44.                     Translation position = GetComponent<Translation>(rigidBody.Entity);
45.                     if (math.lengthsq(location[0].Value - position.Value) <= sqrRadius)
46.                     {
47.                         float3 direction = position.Value - location[0].Value;
48.                         float falloff = radius / math.length(direction);
49.                         float3 force = math.normalize(direction) * 1 * falloff * Time.DeltaTime;
50.                         PhysicsWorldExtensions.ApplyLinearImpulse(world, rigidBodyIndex, force);
51.                     }
52.                 }
53.             }
54.         }
55.     }

I would still love feedback if anyone has any!