KMZ support in Cesium

1. A concise explanation of the problem you're experiencing.

I am trying to get this kmz file working in my version of Cesium (1.39) - "". It seems to load without error but does not function properly (i.e., like it does in Google Earth). When I zoom into a watershed boundary, it should update the map with the outlines of increasingly smaller subbasins. But it doesn't seem to refresh the views based on the network links for the data sources, and I can't figure it out based on my limited understanding of Cesium or find a CZML version.

2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.

<!DOCTYPE html>
<html lang="en">
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
    <meta name="description" content="A simple KML example.">
    <meta name="cesium-sandcastle-labels" content="Showcases, DataSources">
    <title>Cesium Demo</title>
    <script type="text/javascript" src="../Sandcastle-header.js"></script>
    <script type="text/javascript" src="../../../ThirdParty/requirejs-2.1.20/require.js"></script>
    <script type="text/javascript">
        baseUrl : '../../../Source',
        waitSeconds : 60

<body class="sandcastle-loading" data-sandcastle-bucket="bucket-requirejs.html">
    @import url(../templates/bucket.css);
<div id="cesiumContainer" class="fullSize"></div>
<div id="loadingOverlay"><h1>Loading...</h1></div>
<div id="toolbar"></div>

<script id="cesium_sandcastle_script">
function startup(Cesium) {
    'use strict';
var viewer = new Cesium.Viewer('cesiumContainer');
var options = {
  camera :,
  canvas: viewer.scene.canvas,

  text: 'KMZ - watersheds',
  onselect: function () {;
    viewer.dataSources.add(Cesium.KmlDataSource.load('../../SampleData/waters_data_1.8.kmz', options));
}], 'toolbar');

Sandcastle.reset = function() {
    viewer.clock.clockRange = Cesium.ClockRange.UNBOUNDED;
    viewer.clock.clockStep = Cesium.ClockStep.SYSTEM_CLOCK;
if (typeof Cesium !== "undefined") {
} else if (typeof require === "function") {
    require(["Cesium"], startup);


3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

Trying to build an interactive tool for modeling agricultural runoff.

4. The Cesium version you're using, your operating system and browser.

Cesium 1.39, CefSharp with NodeJS .

Hi John,

I’m not too familiar with KML, but have you tried using the update function? It will refresh the network link. I think you may also need to subscribe to the refreshEvent.