Blender to UE5 Skeleton/Animation - Any Pitfalls?

Hello and thanks for your time.

The entirety of my workflow is currently in Blender now except for rigging and animation which is in Maya but I’d like to move that last workflow over to Blender as well. There has been many challenges but I have succeed up to basic tests including root motion. I don’t feel I have complete control however so I’m worried that unforeseen issues may loom further in production and I I’m writing to see if anyone has deeper experience they would be willing to share.

The first issue I encountered was unit scaling using the default FBX exporter. There are solutions to this online but they require many settings and adjustments to the model/armature/bones to be made just for the export process that would have to be reverted post export (of both models and animation). Even with blender python automation this gets complicated when exporting multiple animations etc. The “Better FBX export/import” plugin does solve this issue, I’m not happy about depending on a plugin but the price is cheap enough.

The next issue I encountered was lack of control of joint orientation. This is the one I am most curious about. It’s my understanding that joint orientation shouldn’t matter in Unreal but various 3D applications do have dependency on certain things, IE maya wanting the X axis pointing down bones. I notice that Epic sets up it’s default skeletons with “Behavioral” inversed joined ie: left side of model X points down, right side of model X points up. This is only partially achievable in blender, as the inverse behavioral joints are possible but bones have to be aligned to Y. In regards to this does anyone have experience if issues will arise with UE systems if Y is pointing down bones?

The final problem came in testing root motion. I was able to achieve this but it was also tricky to setup without having control of the rotation of the root bone, it involved a lot of hot/cold with settings to find a combination that aligned the mesh and bones correctly with the same settings in a way that worked with UE root motion, however I’m not sure this will reliably be achievable.

Overall it seems like “Better FBX export/import” is mandatory without creating complex automation and auxiliary export only rigs. I feel I don’t have total control of the results and I am still worried unforeseen issues will arise, or perhaps the X axis down the bones will somehow be required in some aspect of unreal.

Any thoughts or discussion would be greatly appreciated.