Cesium 1.50 : GLTF with RTC extension; visualization issue


1. A concise explanation of the problem you’re experiencing.
When testing a RTC file with Cesium 1.50, I have noticed that the file would be displayed from the origin while having a RTC node. The bounding sphere of the object seems to be alright though

Same file/code with Cesium 1.49/48 displays the model where it should be

2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.

Hello world used with the attached file (I have noticed the file origin was the center of the earth increasing that scale factor)

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

Display Geo referenced gltf files, I am using RTC extension, if it’s not supported by Cesium 1.50, could you let me know a workaround (maybe using a transform node? can it be visualization artifacts?)

4. The Cesium version you’re using, your operating system and browser.

Version 1.50 , Ubuntu 16.04

Chrome Version 69.0.3497.100 (Official Build) (64-bit)

Thanks in advance,


model.gltf (6.11 KB)

Hey Lionel,

We did do some updates to the glTF loading in 1.50. It seems like your glTF is missing an “extensionsUsed” field. That’s what Cesium is checking for in order to apply the extension, so if you just add:

“extensionsUsed” : [




To your glTF it should work!

Thanks, it works fine now :slight_smile: . So then I guess all the extensions used should go to that list right? Then it would look like that if we would use KHR_techniques_webg right?
“extensionsUsed” : [




Yes, that should be correct.

Glad it works!