So I thought over the Christmas break I'd like to learn how to implement character animation (both skeletal for bodies and vertex deformation for faces) into Miranda. To get started I bought a package of positively reviewed animated characters from Infinity PBR in FBX format. The package also included Unity and Unreal files, but FBX is the industry standard and I've used FBX successfully in the past so I figured I should be able to get that to work.
Getting Animations into Blender
I use Blender for my 3D work, so the models needed to work there for me to be able to change or fix them. The main thing though is that I need Blender as a basis to debug my own animation pipeline. In the past I'd buy an FBX, import it into Blender, sometimes having to fiddle with Autodesk FBX Converter to get a model Blender would read, fix up the texture paths in the materials and I'd be done.
This is one of the models I bought. Not exactly an encouraging start.

[Spider?]
The FBX files I bought have PBR materials as you'd expect with modern game art. Blender doesn't even try to import them. I just get grey materials, not even texture file names I can fix up. I'll have to make entirely new materials myself to use any of them. That is disappointing and I have no idea how I'll create new materials that look anything like what the artist intended.
After this utter failure, I did a TON Of research on FBX animation and Blender. I read dozens of articles with people having problems with FBX files in Blender. There were no real solutions. Then I read about a Blender add-on "Better FBX Importer and Exporter" which people seem to like, so I bought that to give it a go.

[Spider (grey)]
So the models look better, but how did Blender do with the animations? Well, mostly it's a ****show. Out of the box, Blender was able to animate one character's eyes, and that's it. Anything with a skeleton was completely mangled. Once I got Better FBX Importer, with some models the vertex animation worked but not the skeletal animation. Some the skeletal animation worked perfectly! Some the skeleton moved but the model didn't. Out of six or so models I tried, two actually looked like they worked correctly. But anything short of 100% really isn't viable for a tiny developer like me.
From Blender to Miranda
With Blender not working, for a second I considered implementing a tool to directly read the FBX files into Miranda's model import tool using the FBX SDK. But that is a non-starter - I need to be able to edit the models and have a visual standard to debug my animation playback against.
Since I've never had much luck with any standard model format, I also started on a Blender Python plugin to export the model data I need from Blender to a simple format my model importer could read (currently it reads Collada files, but that's a dead technology.) Basically it dumps the Blender scene as a text file. I'll probably work on that some more as getting rid of Collada seems like a worthwhile endeavour.
But for my fun animation adventure, I got exactly nowhere.