When setting up a (local) server, as described in the 3D Tiles Samples instructions, then it should be possible to load this tileset with this sandcastle code:
const viewer = new Cesium.Viewer("cesiumContainer");
var tilesetTree = viewer.scene.primitives.add(
new Cesium.Cesium3DTileset({
url: "http://localhost:8003/1.0/TilesetWithTreeBillboards/tileset.json",
})
);
tilesetTree.readyPromise.then(function (tilesetTree) {
viewer.camera.flyToBoundingSphere(tilesetTree.root.boundingSphere);
});
The result should look like the following screenshot:
Can you describe in more detail what you mean by “fading quickly”?