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).
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)