function pickPrimitive(e) {
    const newPick = that._scene.pick({
      x: e.position.x,
      y: e.position.y,
    });
    if (defined(newPick)) {
      that.primitive = defined(newPick.collection)
        ? newPick.collection
        : newPick.primitive;
    }

    that._scene.requestRender();
    that.pickPrimitiveActive = false;
  }
Gets or sets the index of the depth frustum text.  This property is observable.
@type {string}
@default ''