Two components of the same type on one entity

Hi everybody,

It's been a while I wanted to add two ConfigurableJoint to my entities and I really don't know how to do it.

1) If I try in my Archetype I have this answer:

Code (CSharp):

1.         eArch = eMngr.CreateArchetype(
2.             typeof(LocalToWorld),
3.             typeof(Translation),
4.             typeof(Rotation),
5.             typeof(RenderMesh),
6.             typeof(BoxCollider),
7.             typeof(Rigidbody),
8.             typeof(ConfigurableJoint),
9.             typeof(ConfigurableJoint));
10.  

ArgumentException: It is not allowed to have two components of the same type on the same entity. (ConfigurableJoint and ConfigurableJoint)

2) If I try the IBufferElementData I have this answer:

...

Code (CSharp):

1. public struct MyBufferElement : IBufferElementData
2. {
3.     // These implicit conversions are optional, but can help reduce typing.
4.     public static implicit operator ConfigurableJoint(MyBufferElement e)
5.     {
6.        return e.Value;
7.     }
8.     public static implicit operator MyBufferElement(ConfigurableJoint e)
9.     {
10.        return new MyBufferElement { Value = e };
11.     }
12.  
13.     // Actual value each buffer element will store.
14.     public ConfigurableJoint Value;
15. }
16.  

...

Code (CSharp):

1.  
2.         eArch = eMngr.CreateArchetype(
3.             typeof(LocalToWorld),
4.             typeof(Translation),
5.             typeof(Rotation),
6.             typeof(RenderMesh),
7.             typeof(BoxCollider),
8.             typeof(Rigidbody),
9.             typeof(MyBufferElement));
10.  

ArgumentException: MyBufferElement contains a field of UnityEngine.ConfigurableJoint, which is neither primitive nor blittable.

Ok so IBufferElementData are for types like int etc. but not ConfigurableJoint

I tried to think of a better Entity but really my entities need those 2 ConfigurableJoints

So please anyone, do you know how I can do that?

Cheers,

Thierry

 

What do you have inside of ConfigurableJoint? Why can't you make ConfigurableJoint as IBufferElementData?

Code (CSharp):

1. public struct ConfigurableJoint : IBufferElementData {
2. //...
3. }

 

oh, now I realized it is a UnityEngine.ConfigurableJoint which is a class, so, nohow I think, but I'm the beginner in ECS, so, maybe I simply don't know something.
Have you tried ECS Unity Physics package?

 

I never did like that and I'm just curious, what is the point of doing like that?

Code (CSharp):

1. eArch = eMngr.CreateArchetype(
2.             typeof(LocalToWorld),
3.             typeof(Translation),
4.             typeof(Rotation),
5.             typeof(RenderMesh),
6.             typeof(BoxCollider),
7.             typeof(Rigidbody),
8.             typeof(MyBufferElement));

Is it really working? Looks like entity manager ignores all wrong types. But as I said, I don't know the truth and it is interesting for me to know.

 

Does physics 4a. Joints Parade.unity have not multiple joint example by any chance?
EntityComponentSystemSamples/UnityPhysicsSamples/Assets/Demos/4. Joints/

 

Hi @Antypodish thanks for your answers, I'll investigate what you pointed to me, you must be right, UnityEngine.ConfigurableJoint and not using the ECS Unity Physics package may be the problem. I'll look into this and get back to you

 

Hi again @Antypodish and everyone with the same question I had: Actually looking into the physics samples, it makes sense to have 2 kind of entities: firstly, my entities WITHOUT my 2 joints in the Archetype and WITH 2 indexes on entities that I'm going to describe right away: THEN I add another type of entities, different from the previous ones, and each of them will only have in their Archetype one joint joining entities of the previous type... hmmm sorry for my english, I hope it makes sense! Anyway I'm going to try this out and I'll post my progression here.
Cheers
Thierry