Does the Engine Assume Meshes and other Objects as Joints?

This issue had me pull my hair apart, I just can’t jump into the asset aspect of UE4 given how vague the errors I receive are.
Since my last post, I prepared a new model, one that is “cleaner” and suffers no awkward hacky issues - all seems fine, but upon import , I get the classic “Multiple Root Bones Found” error.

I have a rig that uses orientation constraints and IK chains for future animations - it seems to me that UE4 assumes that ALL OBJECTS IN THE SCENE ARE JOINTS?? Someone tell me this isn’t true, but no matter how much I tried to clean up
my hierarchy, the only way I could fix the error is by selecting my mesh, and adding ALL OBJECTS in the scene to my skin modifier(including IK chains, morph targets, and the mesh itself!). You can tell how horribly gross that is, but the model imports nonetheless. This also meant that upon export, the model will include the spline controllers and helpers that are only meant to be there for animation controls!

Can someone confirm if that is true? If so, how do you circumvent it - I find it hard to believe that the engine expects a clean scene with no rig whatsoever. If simply having 1 true root bone isn’t enough, then what other practices should one adhere to? Moreover, it’s very counter-intuitive for me to be forced to include my animation controllers, because I get bombarded by warnings and errors regarding invalid geometry conversion anyways.


are you using Max, Maya, Blender?

Try just exporting the mesh and the skeleton.

Keep the original separately and only export what you need.

I’m using Max - I’ve tried multiple combination of exports. If I don’t include every object in the scene in the skin modifier, a “multiple roots” error is almost guaranteed, which is why I ask the question - does it really expect everything in the SCENE - or what element of the rig/mesh can I be forgetting to account for.
In my example, I have a spline controller that is the parent of the pelvis bone. I use it to animate the pelvis. Intuitively, I would assume that’s a scenario where you either have to break the link and let the pelvis bone remain at the top of the hierarchy, or simply add the controller to your skin modifier. However, the feeling I am getting is - even though the spline controllers and IK chains are not joints and are not profoundly a part of the hierarchy, it still assumes that they are separate root bones that need to be accounted for. Hence, whether they are linked to the bones or not, they still must be included?