code: function() {
      return[
        vec3.fromValues(this._rotation[0], this._rotation[4], this._rotation[8]),
        vec3.fromValues(this._rotation[1], this._rotation[5], this._rotation[9]),
        vec3.fromValues(this._rotation[2], this._rotation[6], this._rotation[10])
      ];
    }
docs: returns the 3 main axes of the current camera rotation