constructor() {
    var self;
    super();
    self = this;
    self.clock = new three__WEBPACK_IMPORTED_MODULE_11__.Clock();
    self.isIOS = isIOS;
    self.isMobile = isMobile;
    self.hasWebXR = isWebXRAvailable;
    self.isAR = false;
    self.isScene = true;
    self.object3D = new three__WEBPACK_IMPORTED_MODULE_11__.Scene();
    self.resize = self.resize.bind(self);
    self.render = self.render.bind(self);
    self.systems = {};
    self.systemNames = [];
    self.time = self.delta = 0;
    self.usedOfferSession = false;
    self.componentOrder = [];
    self.behaviors = {};
    self.hasLoaded = false;
    self.isPlaying = false;
    self.originalHTML = self.innerHTML;
  }
Scene element, holds all entities.

@member {Array} behaviors - Component instances that have registered themselves to be
           updated on every tick.
@member {object} camera - three.js Camera object.
@member {object} canvas
@member {boolean} isScene - Differentiates as scene entity as opposed to other entities.
@member {boolean} isMobile - Whether browser is mobile (via UA detection).
@member {object} object3D - Root three.js Scene object.
@member {object} renderer
@member {boolean} renderStarted
@member {object} systems - Registered instantiated systems.
@member {number} time