Separate rotation transform from parent

Question

I have a hierarchy like this

Body
  - Head
  - Arms

Currently this works fine in that the Body's transformation is reacting as it should. Being children, the Head and Arms match the Body's transform. Is it possible however to separate just the rotation transform? I would like the head to translate with the body but not necessarily rotate the same way.

I tried using Transform.DetachChildren but that removes the translate transform which is a bit of an issue as I move the object using physics so there's a chance the head and arms would react differently and physically separate from the body.

Thanks

Answer 1

This is a script that keeps the rotation of the head to the rotation you set in the script, however it is very simple and may need adjustment to your purpose.(I have included sliders for easy editing). I hope this answers your question.

using UnityEngine;
using System.Collections;

[ExecuteInEditMode] // This allows it to run during editmode(Makes it easier to work with)
public class KeepHeadRotation : MonoBehaviour 
{
Quaternion rotation;
Quaternion newRotation;

[Range(-90,90)]
public float X = 0, Y = 0, Z = 0, W = 0;

void Start()
{
    rotation = transform.rotation;
}

void Update()
{
    newRotation = new Quaternion(rotation.x - X, rotation.y - Y, rotation.z - Z, rotation.w - W);
    transform.rotation = newRotation;
}
}

It works by storing the rotation of the object at the beginning and fixing it to that rotation and the sliders affect the rotation by either adding or subtracting from it allowing you to change it via the script.

Here is the link to the Quaternion page on the Unity API: http://docs.unity3d.com/ScriptReference/Quaternion.html