Using Physics inside SystemBase - dependency issue

When I run this code:

Code (CSharp):

1. using UnityEngine;
2. using Unity.Entities;
3. using Unity.Physics;
4. using Unity.Physics.Systems;
5. using Unity.Jobs;
6. using Unity.Mathematics;
7.  
8. [UpdateAfter(typeof(BuildPhysicsWorld))]
9. public class SystemGun : SystemBase
10. {
11.     protected override void OnUpdate()
12.     {
13.         var physicsWorldSystem = World.GetOrCreateSystem<BuildPhysicsWorld>();
14.         var collisionWorld = physicsWorldSystem.PhysicsWorld.CollisionWorld;
15.  
16.         Dependency = JobHandle.CombineDependencies(Dependency, physicsWorldSystem.FinalJobHandle);
17.  
18.         Entities.ForEach((ref ComponentGun componentGun, ref ComponentPower componentPower) =>
19.         {
20.             var filter = new CollisionFilter
21.             {
22.                 BelongsTo = 1u << 2, // bullets
23.                 CollidesWith = 1u << 1, // enemies
24.             };
25.  
26.             var input = new PointDistanceInput
27.             {
28.                 Position = float3.zero,
29.                 MaxDistance = 10,
30.                 Filter = filter
31.             };
32.  
33.             if (collisionWorld.CalculateDistance(input, out DistanceHit closestHit))
34.             {
35.                 // do stuff
36.             }
37.         }).ScheduleParallel();
38.     }
39. }

I get this error:

InvalidOperationException: The previously scheduled job SystemGun:<>c__DisplayClass_OnUpdate_LambdaJob0 writes to the NativeArray <>c__DisplayClass_OnUpdate_LambdaJob0.JobData.collisionWorld.m_Bodies. You are trying to schedule a new job SystemCollisions:CollisionEventImpulseJob, which reads from the same NativeArray (via CollisionEventImpulseJob.EventReader.m_Bodies). To guarantee safety, you must include SystemGun:<>c__DisplayClass_OnUpdate_LambdaJob0 as a dependency of the newly scheduled job.


Erm what?

Can anyone advise how to fix this up using this ForEach job format?

Thanks!

 

Solved it. By some great fortune there is a very similar thread:

https://forum.unity.com/threads/convert-jobcomponentsystem-to-systembase.894112/#post-5876050

I simply needed this trick to get a RO collisionworld:

public struct CollisionWorldRo
{
[ReadOnly] public CollisionWorld collisionWorld;
}

 

Think I found the proper way to do it:

}).WithReadOnly(collisionWorld).ScheduleParallel();