function parseSide (side) {
    switch (side) {
      case 'back': {
        return THREE.BackSide;
      }
      case 'double': {
        return THREE.DoubleSide;
      }
      default: {
        // Including case `front`.
        return THREE.FrontSide;
      }
    }
  }
Called when entity resumes.
Use to continue or add any dynamic or background behavior such as events.