Check if rotation of model has changed?

Question

How would you check if the rotation of a model has changed? tried:

 var oldRotate = this._target.quaternion;
  console.log('works returns vector3 quaternion: ', oldRotate);
   var newRotate = oldRotate;

      if (oldRotate != newRotate) {
             console.log('this isnt triggering');
     }

this doesn't work and yes it's in a 'loop'

also tried:

 var oldRotation = new THREE.Vector3();
      oldRotation.copy(controlObject.quaternion);
      
      controlObject.position.copy(pos);
      this._position.copy(pos);
  
      this._parent.SetPosition(this._position);
      this._parent.SetQuaternion(this._target.quaternion);
   
  
  
       var newRotation = new THREE.Vector3();
          newRotation.copy(controlObject.quaternion);
  
   console.log(oldRotation.equals(newRotation));

any ideas?

Answer 1

You can't compare objects for equality using the ==/!= operator. This will merely compare the references to the objects, not their values. You will need to compare using the .equals method.

Also, in your example, you're assigning oldR to newRotate directly. I'm not sure if you've not included some intervening code. Either way, you should also be using .clone otherwise the != will never happen.

See: https://threejs.org/docs/#api/en/math/Quaternion for information about the clone and equals methods.