Example of how to use ICollisionEventsJob from Unity.Physics

CalculateDetailsExample.cs

// CollisionResponse option on PhysicsShape must be set to CollideRaiseCollisionEvents.

[UpdateInGroup(typeof(PhysicsSystemGroup))]
[UpdateAfter(typeof(PhysicsSimulationGroup))]
public partial struct CalculateDetailsTest_PhysicsEventSystem : ISystem
{
    [BurstCompile]
    public void OnCreate(ref SystemState state)
    {
        state.RequireForUpdate<SimulationSingleton>();
        state.RequireForUpdate<PhysicsWorldSingleton>();
    }

    [BurstCompile]
    public void OnUpdate(ref SystemState state)
    {
        var physicsWorldSingleton = SystemAPI.GetSingleton<PhysicsWorldSingleton>();

        state.Dependency = new CollisionJob()
        {
            PhysicsWorldSingleton = physicsWorldSingleton
        }.Schedule(SystemAPI.GetSingleton<SimulationSingleton>(), state.Dependency);
    }

    [BurstCompile]
    private struct CollisionJob : ICollisionEventsJob
    {
        // Its important that this is marked as [ReadOnly], otherwise you will get errors.
        [ReadOnly] public PhysicsWorldSingleton PhysicsWorldSingleton;

        public void Execute(CollisionEvent collisionEvent)
        {
            var collisionDetails = collisionEvent.CalculateDetails(ref PhysicsWorldSingleton.PhysicsWorld);

            var avgContactPointPosition = collisionDetails.AverageContactPointPosition;

            Debug.Log($"A: {collisionEvent.EntityA}, B: {collisionEvent.EntityB}, {avgContactPointPosition}");

            foreach(var contactPosition in collisionDetails.EstimatedContactPointPositions)
            {
                Debug.Log($"{contactPosition}");
            }
        }
    }
}

TestPhysicsEventSystem.cs

[UpdateInGroup(typeof(PhysicsSystemGroup))]
[UpdateAfter(typeof(PhysicsSimulationGroup))]
public partial struct TestPhysicsEventSystem : ISystem
{
	[BurstCompile]
	public void OnCreate(ref SystemState state)
	{
		state.RequireForUpdate<SimulationSingleton>();
	}

	[BurstCompile]
	public void OnUpdate(ref SystemState state)
	{
		state.Dependency = new CollisionJob().Schedule(
			SystemAPI.GetSingleton<SimulationSingleton>(), state.Dependency);
	}

	[BurstCompile]
	private struct CollisionJob : ICollisionEventsJob
	{
		public void Execute(CollisionEvent collisionEvent)
		{
			Debug.Log($"A: {collisionEvent.EntityA}, B: {collisionEvent.EntityB}");
		}
	}
}

TouchSystem.cs

public struct Touch : IComponentData
{}

public readonly struct Touched : IComponentData
{
    public readonly Entity Who;
    public readonly float3 Normal;

    public Touched(Entity who, float3 normal)
    {
        Who = who;
        Normal = normal;
    }
}

[UpdateInGroup(typeof(PhysicsSystemGroup))]
[UpdateAfter(typeof(PhysicsSimulationGroup))]
public partial struct TouchSystem : ISystem
{
    [BurstCompile]
    public void OnCreate(ref SystemState state)
    {
        state.RequireForUpdate<SimulationSingleton>();
        state.RequireForUpdate<EndSimulationEntityCommandBufferSystem.Singleton>();
    }

    [BurstCompile]
    public void OnUpdate(ref SystemState state)
    {
        state.Dependency = new CollisionJob()
        {
            TouchLookup = SystemAPI.GetComponentLookup<Touch>(true),
            VelocityLookup = SystemAPI.GetComponentLookup<PhysicsVelocity>(true),
            CommandBuffer = SystemAPI.GetSingleton<EndSimulationEntityCommandBufferSystem.Singleton>()
                                     .CreateCommandBuffer(state.WorldUnmanaged)
        }.Schedule(SystemAPI.GetSingleton<SimulationSingleton>(), state.Dependency);
    }

    [BurstCompile]
    private struct CollisionJob : ICollisionEventsJob
    {
        [ReadOnly] public ComponentLookup<Touch> TouchLookup;
        [ReadOnly] public ComponentLookup<PhysicsVelocity> VelocityLookup;

        public EntityCommandBuffer CommandBuffer;

        private bool IsDynamic(Entity entity) => VelocityLookup.HasComponent(entity);
        private bool IsTouchable(Entity entity) => TouchLookup.HasComponent(entity);

        public void Execute(CollisionEvent collisionEvent)
        {
            var entityA = collisionEvent.EntityA;
            var entityB = collisionEvent.EntityB;

            if(IsTouchable(entityA) && IsDynamic(entityB))
            {
                CommandBuffer.AddComponent(entityA, new Touched(entityB, collisionEvent.Normal));
            }
            else
            if(IsTouchable(entityB) && IsDynamic(entityA))
            {
                CommandBuffer.AddComponent(entityB, new Touched(entityA, collisionEvent.Normal));
            }
        }
    }
}

Even better is the version tertle provides (https://github.com/tertle/com.bovinelabs.core) under PhysicsStates

Thank you so much! This is super helpful..

This example save my life 😁 Thank you so much !

Any ideas how to get the contact point? Using monobehavior it would be something like collision.GetContact(0).point.... or collider.ClosestPoint(vector).
I saw a hint suggesting to use AverageContactPointPosition in collisionEvent.CalculateDetails.... but I don't know how to reference Physics World without getting console errors

added new example to do this.

Awesome 😎
Thank you very much!
I had to pass in ref new PhysicsWorld() which worked for some reason. But I'll change it to your version.