Import / export algorithms and variant tree structures...

I've been comparing some 'good' vs 'bad' FBX files to try to spot why the latter fail. Given all open correctly in AutoDesk's free FBX toolkit, their newer Reviewer and a bunch of other programs, yet scant few in Poser & Co, it was a puzzle. Also, some modelling programs report all sorts of missing rigging. Yet, IIRC, different programs report different errors.

I took a look using free Open3D Model Viewer, which has an option to display hierarchies in a reasonably comprehensible manner. Now, it is sorta obvious what's wrong. The 'good' FBX files generally have a 'trad' tree. The 'bad' files have all the necessary info, but arranged differently. If you're lucky, each sub-rig imports to Poser hierarchy as a stand-alone module. Otherwise, you get all those sub-rigs, plus mutations ranging from 'wonky legs' through 'half-flipped' unto totally trashed 'transporter accident'...

I give you Cendrillon (splat), Sadira (see above) and Courtney (good)...

As you see, it comes down to the work-path's I/O algorithms, variance of tree structure and the tolerance of import algorithms...

So, all you Modellers, what shape of tree does your FBX I/O plug-in produce, and does Poser like it ??