RuntimeError: Unsupported glTF Extension: KHR_techniques_webgl


having built the 3D Tiles Samples Generator from when attempting to display the “TilesetWithTreeBillboards” 3d-tiles tileset Cesium v1.49 triggers the following runtime exception:

An error occurred while rendering. Rendering has stopped.

RuntimeError: Unsupported glTF Extension: KHR_techniques_webgl


at new t (http://localhost:8084/ThirdParty/Cesium/Cesium.js:451:28523)

at Object.A.checkSupportedExtensions (http://localhost:8084/ThirdParty/Cesium/Cesium.js:501:17740)

at xe.update (http://localhost:8084/ThirdParty/Cesium/Cesium.js:503:8500)

at x.update (http://localhost:8084/ThirdParty/Cesium/Cesium.js:515:2972)

at A.update (http://localhost:8084/ThirdParty/Cesium/Cesium.js:515:10968)

at N.process (http://localhost:8084/ThirdParty/Cesium/Cesium.js:517:29584)

at Z (http://localhost:8084/ThirdParty/Cesium/Cesium.js:518:25634)

at V.update (http://localhost:8084/ThirdParty/Cesium/Cesium.js:519:611)

at a.update (http://localhost:8084/ThirdParty/Cesium/Cesium.js:496:10993)

at ot (http://localhost:8084/ThirdParty/Cesium/Cesium.js:532:22244)

After a bit of online research I came up to the conclusion that either Cesium doesn’t support that glTF 2.0 extension yet or my WebGL driver doesn’t.

Not sure which one of them though.

Has the AGI gltf pipeline (used to create the instanced i3dm tree 3d-tiles tileset) to use the 2.0 glTF version instead of the 1.0 (if that being the culprit of the problem)?

I need to display 3d trees on a Cesium map, how to solve or circumvent the problem?

Cesium 1.49, Chrome Version 68.0.3440.106 (Official Build) (64-bit), Windows 7 64bit.

Please help with this issue, thanks.

Thanks for reporting this! Looks like this is fixed with the new materials update, which added support for that extension:

This should be out in the next Cesium version (1.50) on October 1st, or you can try using the master branch right now. I confirmed that this does work on there.

Thanks very much Omar,

in the meanwhile I converted the Tree.glb and Tree_Billboard.glb models to glTF 1.0 and it worked.

I’ll wait for the release 1.50.