I just discovered the way to include OSM building data in a Cesium project. It sounds great but I also (re)-discovered my local ellipsoid vertical offset with the global WGS84 one (see pictures).

UFO buildings

The "flying buildings syndrome" (they are certainly at the ground level referenced on the WGS84, but the local terrain tiles seem not, or I missed something).

Vertical offset Bessel-WGS84 We live 'on' the Bessel ellipsoid which is 50m lower than the WGS84.

I may be wrong in my hypothesis, so let me know if it's the case.

Here is my question;

Did I miss something, e.g. to base the terrain tiles on the WGS84 ellipsoid?
If not, is there a way to fix this, for example by setting a different ellipsoid, more accurate locally than the global WGS84?
Or, any mean to bring the building back down to the ground?


1 Answer 1


I found a solution, that is add Cesium Terrian option, because Cesium OSM buildings are built for the Cesium Terrain.

Example: Like this

Thank you for the information. I would start by ensuring that the terrain you generated is being added to the Cesium viewer correctly.

Cesium OSM buildings are built for the Cesium Terrain. They are not designed to adapt to any terrain added to the Cesium viewer. Thus, seeing the Cesium OSM buildings floating in the air when added to a new terrain is not a bug.

To populate your custom terrain with buildings, I suggest that you upload your desired building models to your Cesium ion account. Next, place the models in your terrain at specified coordinates. This guide will help you set the location of data uploaded to Cesium ion:

As always, more information helps me give you better assistance. Could you tell me a little bit more about your use case and desired functionality? Let me know if you have any questions or concerns!



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