getWorldPosition(vec3 ) {
    this.updateMatrices()
    return (vec3 || new Vector3()).setFromMatrixPosition(this.threeObject.matrixWorld)
  }
Get this object's current position in world space
@param {Vector3} [vec3] - optional Vector3 object to populate with the position;
                 if not passed in a new one will be created.
@returns {Vector3}