Unsupported glTF Extension: KHR_technique_webgl

1. A concise explanation of the problem you're experiencing.

An error occurred while rendering. Rendering has stopped.
RuntimeError: Unsupported glTF Extension: KHR_technique_webgl
    at new t (http://localhost:8081/Build/Cesium/Cesium.js:444:28523)
    at Object.F.checkSupportedExtensions (http://localhost:8081/Build/Cesium/Cesium.js:493:30361)
    at be.update (http://localhost:8081/Build/Cesium/Cesium.js:496:14415)
    at T.update (http://localhost:8081/Build/Cesium/Cesium.js:505:22252)
    at F.process (http://localhost:8081/Build/Cesium/Cesium.js:511:1152)
    at K (http://localhost:8081/Build/Cesium/Cesium.js:511:29631)
    at G.update (http://localhost:8081/Build/Cesium/Cesium.js:512:4986)
    at a.update (http://localhost:8081/Build/Cesium/Cesium.js:489:10993)
    at et (http://localhost:8081/Build/Cesium/Cesium.js:525:24190)
    at Ze (http://localhost:8081/Build/Cesium/Cesium.js:525:21751)

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

I use cesium 1.50 ,load 3DTiles ,then,it errors

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

4. The Cesium version you're using, your operating system and browser.
cesium1.50 chrome

Thanks for reporting this. Did you use Cesium ion to generate this tileset? The extension name is KHR_techniques_webgl, (notice the s), so it sounds like this model might have been generated incorrectly.


we have the same problem. The cesium implementation changed the extension name from KHR_technique_webgl to KHR_techniques_webgl with the 1.50 release. See: https://github.com/AnalyticalGraphicsInc/cesium/blob/1.49/Source/Scene/ModelUtility.js#L145

So our tilesets we created ourselfs also have the wrong extension name “KHR_technique_webgl” in the tilesets.

Maybe you can keep the KHR_technique_webgl to preserve compatibility with old datasets ?


Oh, I didn’t realized the extension was renamed at some point. I couldn’t find a breaking change for this listed, so I brought this up here:

I’ll update this thread back once there’s a resolution, but feel free to follow that issue or chime in there too.

Ok, I think the issue here is that even though it was included in the 1.49, it was never officially supported or documented, that’s why there wasn’t a breaking change and deprecation period. Kudos for being on the cutting edge, but sometimes it comes at a price!

From what I can tell, it looks like it’s just not purely a naming issue. The tiles that were generated using the old specification might have unintended behavior. I think it might be easiest to re-convert your models with the latest obj2gltf. Does that work for you all?