Cesium CZML performance issues

Hi Team,

I am working on migrating Google Earth plugin to Cesium. I am facing issues related to loading of large KMZ files of size 132 KB. This KMZ file is loaded in cesium globe, but movement of the globe is freezed after loading.

      So, i thought about using CZML format. Now before proceeding with CZML, i would like to know is there any performance issues like KML with the latest cesium build 1.18?

      And is there any tool to convert KML to CZML?

Kindly provide me the input move forward.


Hello Dipej,

Glad to hear you chose Cesium! What kind of project are you working on?

Regarding the freezing, I’ve created an issue here to look into improving the loading of larger data source files: https://github.com/AnalyticalGraphicsInc/cesium/issues/3572



Hi Hannah,

Thanks for your reply.

I am working in Java based GWT project, along with Cesium(javascript) globe we also have the GWT javascript which will be running in the web browser.

I have observed a KMZ(132 kb) file is loading successfully without any lag in Cesium Viewer. But in my application, same KMZ takes time to load and after loading it is freezing.

That is the reason why we are looking at the alternatives for KMZ, as performance improvements in Cesium related to KMZ/KML are yet to be implemented.

Kindly suggest on below items:

1. Is there any tool to convert KML to CZML
2. Understanding of CZML with respect to KML
3. Any performance issue in CZML, while loading of big files


Hmm, I can’t think of a reason the KMZ would load fine in the viewer app but not in your own application.
I don’t know that CZML would necessarily load faster than KML. The lag I’ve seen with other large data files is caused by when creating all of the DataSource properties. The CZML and KML files would result in creating the same number of properties, so I’m not sure that’s the answer.

Sorry I don’t have any better advice. Since the file loads without lag in Cesium Viewer, maybe there’s something else you can change in your application to help prevent the lag.