koobas.hobune.stream
Get local euler angles by Quaternion
What do I need that is to get object's local euler angles by given global rotation. One solution is to set object required rotation and then roll back, but it seems ugly:
static Vector3 GetLocalEulerAtRotation(this Transform transform, Quaternion targetRotation)
{
var tempRotation = transform.rotation;
transform.rotation = targetRotation;
var localEuler = transform.localEulerAngles;
transform.rotation = tempRotation;
return localEuler;
}
Is there any another more compact and more optimized solution?
Best Answer
You seem to abuse a child object as temporary conversion object while you actually want to access the rotation of the parent object. The local eulerangles define the rotation of the transform in the parents coordinate space. So if your targetRotation quaternion is an absolute / worldspace rotation all you need is the inverse of the parents transform
So to replace your current code you can just do:
static Vector3 GetLocalEulerAtRotation(this Transform transform, Quaternion targetRotation)
{
var q = Quaternion.Inverse(transform.parent.rotation) * targetRotation ;
return q.eulerAngles;
}
It would make more sense to use the transform as local space instead of the parent of the object
