Rotating a quaternion to face a relative target overtime

gistfile1.txt

//http://blog.infrared5.com/
protected Vector3 relativePos;
protected Quaternion rotationVector;
protected void UpdateRotationVector()
{
    relativePos =  currentTarget.transform.position - transform.position;
    rotationVector = Quaternion.LookRotation(relativePos);
}
Now, in the updateRotation method, we rotate the ship elegantly toward the new way point, and all you have to do is adjust “actualSensitivity” to achieve whatever aggressiveness you’re after:

protected Quaternion rotQ;
protected float yRot = 0;
protected float lastYRot;
protected void UpdateRotation()
{
    rotQ = Quaternion.Lerp(transform.rotation, rotationVector, Time.deltaTime*actualSensitivity);
    transform.rotation = rotQ;

    // this next bit is to get them to bank into their turns
    yRot = lastYRot - transform.localEulerAngles.y;
    yRot = Mathf.Clamp(yRot, 0, 3);
    transform.Rotate(0,0, yRot, Space.Self);

    lastYRot = transform.localEulerAngles.y;
}