const tileset = new Cesium.Cesium3DTileset({ url: '../../assets/data/NewYork/tileset.json' });

    viewer.scene.primitives.add(tileset);

    tileset.readyPromise.then(function(tileset1) {

      viewer.scene.primitives.add(tileset1);

      viewer.zoomTo(tileset1, new Cesium.HeadingPitchRange(0.5, -0.2, tileset1.boundingSphere.radius * 1.0));

}).otherwise(function(error) {

      console.log(error);

});