Help! Child rotation, negate offset of parent rotation?

Hello.
I've got a little issue here, that I've been trying to tackle for weeks.

I have a turret, on a ship, that I need to rotate to face a direction in World Space.
However, to do so I need to offset the rotation of it's parent.

How can I do that?

I attempted to get the offset like this:

Code (CSharp):

1. quaternion worldForwards = new quaternion(0, 0, 0, 1f);
2. quaternion offset = math.mul(worldForwards, parentQuaternionRotation);

However, it's rotations are not correct when applied to the final quaternion ( see below )

Here is my code in pure form. float3 is synonymous with Vector3 in Unity.Mathematics

Code (CSharp):

1. float3 targetDirection = math.normalize(targeting.relativeTargetPosition);
2. float3 up = parentLocalToWorld.localToWorld.Up;
3. quaternion parentRotation = parentLocalToWorld.localToWorld.Rotation;
4. quaternion thisRotation = localToWorld.Rotation;
5.  
6. quaternion final = quaternion.LookRotation(targetDirection, up); // Rotation must respect parent up axis.
7.  
8. rotation.Value = final; // final will be offset by parentLocalToWorld.rotation, need to negate.
9.  

 

Hello Melv, thanks I'd appreciate it if you would.
Though, this isn't specifically a DOTS issue. It's just Quaternion math. Was hoping someone could teach me.

 

Thank you very much! That's very helpful.

 

Hey @Lapsapnow , or anyone for that matter. I am attempting to do something similar and cannot seem to follow. Did you end up figuring this out? And could you elaborate?