title: lookAt for child object
body: <p>Trying to make a CHILD of an object look at a position (which is in global/world space)</p>
  <p>Here's what I've got, but it doesn't work.
  Direction of arrow seems to roam around in unpredictable directions.</p>
  <p><strong>Update</strong> (added example): <a href="https://jsfiddle.net/um8cxp3b/27/" rel="nofollow noreferrer">https://jsfiddle.net/um8cxp3b/27/</a></p>
  <pre class="lang-js prettyprint-override"><code>makeArrowLookAt(obj, position) {
   
    // obj.lookAt(position); // works PERFECTLY, but I want a child object to lookAt...
        
    const posVector = new THREE.Vector3().copy(position); // copy
    const localVector = obj.worldToLocal(posVector); // get local position offset
    localVector.normalize(); // converts local offset to rotation... right?
        
    // Apply the localised rotation to the object
    obj.children[0].rotation.x = localVector.x;
    obj.children[0].rotation.y = localVector.y;
    obj.children[0].rotation.z = localVector.z;
  }
  </code></pre>
  <p>(Note the child in this case is an arrowHelper to illustrate direction)</p>