Thanks for the pull request @lilleyse!

• ✔️ Signed CLA found.
• ❔ CHANGES.md was not updated.
  • If this change updates the public API in any way, please add a bullet point to CHANGES.md.
• ❔ Changes to third party files were made.
  • Looks like a file in one of our ThirdParty folders (ThirdParty/, Source/ThirdParty/) has been added or modified. Please verify that it has a section in LICENSE.md and that its license information is up to date with this new version.

Reviewers, don't forget to make sure that:

• Cesium Viewer works.
• Works in 2D/CV.
• Works (or fails gracefully) in IE11.

I am a bot who helps you make Cesium awesome! Contributions to my configuration are welcome.

🌍 🌎 🌏

@lilleyse do you think #6805 will make it in this release? I don't think we should merge this workaround if we're going to have the actual solution ready to go shortly

Fine by me, #6805 should made the release.

It's looking like #6805 won't make the release so I reopened this PR.

I'm still not convinced we should rush to get this workaround in for the release since we have the actual fix coming soon. Was this issue a common problem that a number of our users are experiencing?

It has been brought up twice

• An error occurred while rendering. Rendering has stopped #6940
• Cesium no longer adds a default material for gltf 2.0 as needed #6891

Okay, that's significant

Who should review this? @likangning93?

I think @ggetz has more familiarity with the gltf-pipeline code and would be better to review this.

Since Source/ThirdParty/GltfPipeline/addDefaults.js will be overridden by the rebuilt GltfPipeline files, I think this fix will be fine temporarily.

Code looks good and the model from #6891 loads correctly. Thanks @lilleyse !

@lilleyse open an issue or add a comment to #6805 to revert this workaround when the actual fix comes in.

#6805 completely rebuilds the files in GltfPipeline from the new master (as opposed to a previous branch just fro cesium) so this fix will already be overridden.