3DTiles data used "KHR_techniques_webgl"

I have some 3DTiles data used “KHR_techniques_webgl” extension,How can I convert these 3DTiles data into data that Cesium can currently use ?

It is not always possible to automatically upgrade tile data that uses the KHR_techniques_webgl extension. (With this extension, each tile can basically contain arbitrary shader code, which can not necessarily be mapped to glTF 2.0 PBR, for example).

But the upgrade command of the 3d-tiles-tools should be able to upgrade this data in most cases. You might want to give this a try.

(If it does not work as expected, it might be possible to create a “special” upgrade process for this data, but that might require some more time and investigation)