How to convert the quaternion from local SR to global SR?

[alunAlunnnnn]

Hello,

I'm tring to convert I3S 3D-Object Scene Layer data to other format, most of them are wonderful to display, when I have converted it. But the OBB works not very well.

When I convert I3S data with EPSG:4326, all of them have a good work. But if the I3S data have EPSG:3857, the quaternion can not fit with the global, which have not any terrain data.

It looks like below

The quaternion in one node is [0, 0, 0.93927725010939966, -0.34315921585602843], convert to euler xyz rotate is [ 0. 0. -2.44103607], it seems there are no x rotate and y rotate data to make the OBB have a correct rotate in EPSG:4326 global.

Could I convert a quaternion correctly from EPSG:3857 to EPSG:4326? for some reason, I can not use ArcGIS Pro Desktop or it's SDK to do this job.

The nodepage data is here

Thanks a lot.