CZML bug in 1.3 ?


We have been working with a CZML file showing flight tracks using Cesium 1.1 (in our app) and 1.2 (in the demo early yesterday )

Using the current CesiumViewer demo (or Viewer in Sandcastle), our flight tracks will play for a period of time, then crap-out with the following exception:

I will be happy to send our CZML file upon request from CZML developer.


An error occurred while rendering. Rendering has stopped.
DeveloperError: index is required.
    at new DeveloperError (
    at PolylineCollection.get (
    at PolylineUpdater.updateObject (
    at PathVisualizer.update (
    at DataSourceDisplay.update (
    at Event.raiseEvent (
    at Clock.tick (
    at CesiumWidget.render (
    at render (

Unfortunately, this is my fault. I accidentally introduced a regression while working on a different issue; and due to lack of test coverage in that area of the code (also my fault), it snuck into the 1.3 release.

The good news is I’ve already added a test and fixed the issue. See for the change. If you’re using an AMD based app; you can just grab PathVisualizer.js and overwrite the one in 1.3 to patch your version. If you’re using the combined Cesium.js, then you’ll need to build Cesium from source with the fix (which is easy to do if you follow our Contributor’s guid:’s-Guide