Using cesium.js within Jupyter, web workers do not terminate, leaking resources

CesiumJS
4

I’m using JupyterLab 1.0, running inside a docker container for development. Try this as a hello world, running it inside one step. It’s a bit hacky, admittedly.

def cesium_html():

return \

    """

      <iframe style="width: 1024px; height: 768px; overflow:hidden; border: 0px; margin: 0px" scrolling="no"

        frameborder="0" marginheight="0" marginwidth="0" sandbox="allow-scripts" srcdoc='

        <!DOCTYPE html>

        <html lang="en">

        <head>

          <meta charset="utf-8">

        </head>

        <body>

          <script src="https://cesiumjs.org/releases/1.60/Build/Cesium/Cesium.js"></script>

          <link href="https://cesiumjs.org/releases/1.60/Build/Cesium/Widgets/widgets.css" rel="stylesheet">

          <div id="cesiumContainer" style="width: 1024px; height:768px"></div>

          <script>

            //Cesium.IondefaultAccessToken = "your_access_token";

            var viewer = new Cesium.Viewer("cesiumContainer");

          </script>

        </body>

        </html>

      '></iframe>

    """

import IPython.display

IPython.display.HTML(cesium_html())

You should see a cesium globe appear. The iframe was necessary to avoid leaking the web worker threads, which will eventually cripple your computer :slight_smile:

In use case, I’m using CZML, with the czml3 python library, to create and render my data inside cesium, though I’ll probably switch to native javascript soon as I need more flexibility.

I’m not a Jupyter expert, so there is probably a better way. I expect that the right way to do this is a formal “widget”, something like https://github.com/petrushy/CesiumWidget/blob/master/CesiumWidget/cesiumwidget.py, but it’s a bit out of date and I haven’t tried it. There’s also https://github.com/sinhrks/cesiumpy/tree/master/cesiumpy but it also is a bit neglected and didn’t work for me, so I ended up doing my own thing.