"Cannot read property 'extras' of undefined" while loading gltf model

I am running Cesium 1.48 on **electron 1.8.7 ** . I am getting this error “*Cannot read property ‘extras’ of undefined” *while loading a gltf model like this:

position: cartesian,
show: true,
model: {
uri: Cesium.buildModuleUrl(‘Assets/Textures/model.gltf’),
scale: 50,


The same code works on chrome. I have failed to find what causes this error. Can somebody help resolving this?

Update: It doesn’t work on chrome too. Between, the same code works on chrome with cesium 1.46. But i can’t use 1.46 with electron because that version had problems with loading local images/resources in electron using Resource class.

Attached is gltf file

model.gltf (569 KB)

Just fixed it. I was exporting a dae to gltf using blender. But then i exported dae to obj and converted it to gltf using cesium’s model converter . Still don’t know why it was working in 1.46 and not in 1.48

Glad you found a workaround! This might be related to differences in materials when converting obj to gltf versus collada to gltf, would it be possible to provide the textures and bin file that go with this model for debugging?

Ah, no need. I was able to reproduce this… it looks like Cesium’s handling of “default materials” for portions of the gltf without a material broke between 1.47 and 1.48. I’ve opened an issue here: https://github.com/AnalyticalGraphicsInc/cesium/issues/6891

Hello Kangning,
Thanks for the update. Glad that you found the issue. Let me know if I can help in anyway.

Ah. Forgot to come back and update this, default materials are back for 1.49.