I finally found the specific setup required to export FBX to UE4 with the appropriate scale and root motion. This is great! I can use Houdini for rigging and animation.

However, there are still some issues with generated bone structure. There are what appear to be unnecessary “end_effector” joints, and any nodes in the structure also get inserted into the exported skeleton. E.g., if the chain_root isn't in “/obj”, it no longer gets to be the actual root bone, and that's a big problem. Specifying a “startnode” to the FBX exporter also prepends a “world_start” before the root bone. While I can put the entire skeleton in “/obj”, this seems a bit annoying and counter to using Houdini's features.

Is there a way to generate a bone structure extracted/baked from the “actual” bone structure? There doesn't appear to be a lot of control over the FBX export, and I'm obviously pretty new to Houdini and not sure how you'd generate a kind of “logical” node structure to be passed to the FBX exporter.