Having problems with a simple Rotate System

Hi,
I feel very stupid, but I could not get that simple Rotation System to work.

Here is the code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using Unity.Collections;
5. using Unity.Entities;
6. using Unity.Transforms;
7. using Unity.Mathematics;
8. using System;
9. using System.Runtime.CompilerServices;
10.  
11. public class OneRotationSystem : ComponentSystem {
12.  
13.     public struct CubeGroup {
14.         public ComponentDataArray<Rotation> cubeRotation;
15.         public EntityArray Entities;
16.         public readonly int Length;
17.     }
18.  
19.  
20. #pragma warning disable 649
21.     [Inject] private CubeGroup cubeGroup;
22. #pragma warning restore 649
23.  
24.     protected override void OnUpdate()
25.     {
26.         float dt = Time.deltaTime;
27.         float speed = 100;
28.  
29.         for (var i = 0; i < cubeGroup.Length; ++i)
30.         {
31.             var rotation = cubeGroup.cubeRotation[i];
32.             rotation.Value = math.mul(math.normalize(rotation.Value), quaternion.AxisAngle(math.up(), dt * speed));
33.         }
34.     }
35. }
36.  

My entities, have Position, Rotation and MeshInstanceRenderer Components. I have instantiated them and I see them in the scene, but I could not modify the rotation, I have a feeling that something is overwriting the old value every frame I try to modify it.

I am using Unity 2018.3b11 and the latest Entities version available in the Package Manager.

Thanks!

 

You're only modifying a local copy of rotation.

Remember that ComponentData are structs, not a classes, so you need to apply it back.

Code (CSharp):

1.             var rotation = cubeGroup.cubeRotation[i];
2.             rotation.Value = math.mul(math.normalize(rotation.Value), quaternion.AxisAngle(math.up(), dt * speed));
3.             cubeGroup.cubeRotation[i] = rotation;

Side note, [Inject] and ComponentDataArray are being removed so you should look into chunk iteration.

 

Are you sure about ComponentDataArray?

 

Recommend to whatch last talk of unite LA day 2 - ECS: The Evolution of the ECS API

also here you can read about other reason: https://forum.unity.com/threads/per...due-to-ever-increasing-archetype-count.567418

 

I feel like it's easier to write common tasks with Jobs than regular systems now.

IJobProcessComponentData / IJobProcessComponentDataWithEntity and substractive attributes just saving me from using Chunk iteration by hand.

Spoiler

Code (CSharp):

1. using Unity.Entities;
2. using Unity.Jobs;
3. using Unity.Mathematics;
4. using UnityEngine;
5.  
6. [UpdateAfter(typeof(RemoveHeatingSystem))]
7. public class DecreaseTemperatureSystem : JobComponentSystem
8. {
9.     [RequireSubtractiveComponent(typeof(Heating))]
10.     private struct DecreaseTemprerature : IJobProcessComponentData<Temperature>
11.     {
12.         public float Delta;
13.         public void Execute(ref Temperature data)
14.         {
15.             data.Value = math.max(data.Value - Delta, 0f);
16.         }
17.     }
18.    
19.     protected override JobHandle OnUpdate(JobHandle inputDeps)
20.     {
21.         return new DecreaseTemprerature{Delta = Time.deltaTime}.Schedule(this, inputDeps);
22.     }
23. }

 

Thanks SubPixel