compressVertices in 1.3 possible bug

Hi there,

We upgraded our app from v1.2 to v1.3 and everything is fine except for one issue, it seems that enabling ‘compressVertices’ breaks us, the moment we load a CZML we get this:

An error occurred while rendering. Rendering has stopped.

DeveloperError: Appearance/Geometry mismatch.
The appearance requires vertex shader attribute input ‘compressedAttributes’, which was not computed as part of the Geometry. Use the appearance’s vertexFormat property when constructing the geometry.

Error at new DeveloperError
( at validateShaderMatching ( at Primitive.update ( at PrimitiveCollection.update ( at updatePrimitives ( at render ( at Scene.render ( at CesiumWidget.render ( at render (


If we change line 76522 of the Cesium.js (unminified) from:
this._compressVertices = defaultValue(options.compressVertices, true);
this._compressVertices = false;

everything is fine.

so how should we proceed ? should we be explicity be asking that our CZML geometries are not compressed by the new CzmlDataSource (i.e. is this a new attribute in the CZML?), or should we be setting the appearance of the polygons differently in our CZML?

let me know if i can provide anything further to help reproduce this at your end.



Can you share the CZML file? Or at least a snippet of it that you believe is causing the issue?

sure thing, it is attached. note that the polygons have holes, which (i believe) are not currently supported by czml, so the holes are currently represented as additional polygons in the czml.


-i (580 KB)

Ivan, the CZML you attached loads without any problems for me. Have you tried loading it into the default Cesium Viewer app? It’s also possible that you are having a machine/video card specific problem. What OS/browser/video card are you using? Can you make sure you’re on the latest drivers. Finally, if updating drivers doesn’t fix it; can you go to and copy/paste the results?


PS: Looks pretty cool.

Embarrassingly i can now no longer reproduce this on my end, despite having spent several hours with it the day I originally wrote.

I can only assume that rebooting my machine over the weekend ‘cured’ it.

The original CZML works in the cesium viewer (although i had never tested that previously) and our site now works with the unmodified Cesium.js

sorry for the noise, and, as always, awesome work Cesium devs !