Uploading KML/KMZ: heading and altitude data are ignored


i am struggling with uploading 3D-Models via KMZ into ION producing correct results.

Since the heading und altitude data are crucial, especially heading reflecting the meridian convergence correction. These small angles are crucial for correct and precise positioning, but seems being constantly ignored by Ion resulting in wrong visualisation.
I am sticking to these format specifications:

kml_dae_demo_neu.kmz (2.0 MB)

If i upload a single model file (i tried both variants: gltf/glb and dae-coded file) and input the location data manually including the important heading information, the model gets perfectly adjusted in its environment.

But why are the provided Orientation data are always skipped when using KMZ-upload ?

May be the Cesium team have a say in this matter…


Hi Fred,

The alignment of your models is not correct because the values of heading in your data are not valid. You provided negative numbers, however KML expects values in the range of 0 - 360 for heading. If you update your file to use values in the range of 0 - 360 degrees it should work.

Hello again,

thank you very much for this very important piece of information.

I am always got used to think in -180…180 degree notation and you remind me to
use the 0…360° scope! I have to get familiarized with the idea, that small negative
angles are equal to their bigger counterparts (alpha + 360).

And with the corrected kml file it works now:
The street segments now fit perfectly together, the small gaps are du to projection to ellipsoid surface.

At first glance i thought, the altitude information was still not respected. But it is only in the asset preview.
Later, when i visualize the asset in my CesiumJs-Web-Application everythink is fine:

Thanks a lot, problem solved.


i send the same picture two times by mistake.
here is the missed one:
And this is the corrected version of the KMZ-File
kml_glb_360.kmz (987.8 KB)