getAttribute(attr) {
    // If component, return component data.
    var component;
    if (attr === 'position') {
      return this.object3D.position;
    }
    if (attr === 'rotation') {
      return getRotation(this);
    }
    if (attr === 'scale') {
      return this.object3D.scale;
    }
    if (attr === 'visible') {
      return this.object3D.visible;
    }
    component = this.components[attr];
    if (component) {
      return component.data;
    }
    return window.HTMLElement.prototype.getAttribute.call(this, attr);
  }
If `attr` is a component, returns ALL component data including applied mixins and
defaults.

If `attr` is not a component, fall back to HTML getAttribute.

@param {string} attr
@returns {object|string} Object if component, else string.