Simple movement example throw exception.

So I'm playing around with ECS and am trying to set up a simple example of moving an existing GameObject (cube).

I've added the GameObjectEntitiy, PositionComponent, HeadingComponent, MoveForwardComponent, MoveSpeedComponent, and CopyTransformToGameObjectComponent to my cube. I've set the heading to (0, 0, 1) and the move speed to 1.

When I run this however I get the following exception.

InvalidOperationException: The NativeArray CopyTransforms.entities must be marked [ReadOnly] in the job CopyTransformToGameObjectSystem:CopyTransforms, because the container itself is marked read only.
Unity.Jobs.LowLevel.Unsafe.JobsUtility.ScheduleParallelForTransform (Unity.Jobs.LowLevel.Unsafe.JobsUtility+JobScheduleParameters& parameters, System.IntPtr transfromAccesssArray) <0x3607b350 + 0x00072> in <a58d63d105984c39abb8652b638a76b1>:0
UnityEngine.Jobs.IJobParallelForTransformExtensions.Schedule[T] (T jobData, UnityEngine.Jobs.TransformAccessArray transforms, Unity.Jobs.JobHandle dependsOn) (at C:/buildslave/unity/build/Runtime/Jobs/Managed/IJobParallelForTransform.cs:58)
Unity.Transforms.CopyTransformToGameObjectSystem.OnUpdate (Unity.Jobs.JobHandle inputDeps) (at C:/ProgramData/Unity/cache/packages/staging-packages.unity.com/com.unity.entities@0.0.11/Unity.Transforms.Hybrid/CopyTransformToGameObjectSystem.cs:54)
Unity.Entities.JobComponentSystem.InternalUpdate () (at C:/ProgramData/Unity/cache/packages/staging-packages.unity.com/com.unity.entities@0.0.11/Unity.Entities/ComponentSystem.cs:353)
Unity.Entities.ScriptBehaviourManager.Update () (at C:/ProgramData/Unity/cache/packages/staging-packages.unity.com/com.unity.entities@0.0.11/Unity.Entities/ScriptBehaviourManager.cs:82)
Unity.Entities.ScriptBehaviourUpdateOrder+DummyDelagateWrapper.TriggerUpdate () (at C:/ProgramData/Unity/cache/packages/staging-packages.unity.com/com.unity.entities@0.0.11/Unity.Entities/ScriptBehaviourUpdateOrder.cs:59)

How do I fix this?

 

this is your answer

 

The problem I believe, is that the 'CopyTransformToGameObjectSystem' script is provided with the ECS.

 

Yes, all of those components are part of Unity's ECS. I didn't write them.

 

Any ideas? As I see EntityArray in Job does not change and ReadOnly attribute should not interfere

Code (CSharp):

1. [ComputeJobOptimization]
2.         struct CopyTransforms : IJobParallelForTransform
3.         {
4.             [ReadOnly] public ComponentDataFromEntity<Position> positions;
5.             [ReadOnly] public ComponentDataFromEntity<Rotation> rotations;
6.             public EntityArray entities;
7.  
8.             public void Execute(int index, TransformAccess transform)
9.             {
10.                 var entity = entities[index];
11.  
12.                 if (positions.Exists(entity))
13.                 {
14.                     transform.position = positions[entity].Value;
15.                 }
16.                 if (rotations.Exists(entity))
17.                 {
18.                     transform.rotation = rotations[entity].Value;
19.                 }
20.             }
21.         }

 

Yes, I did, I created my MyCopyTransformToGameObjectComponentWeNeedMoreLettersInTitle