When I import my skeletal mesh from blender, it appears to have an extra bone that does not exist in the original armature. This bone is placed at the very top of my hierarchy, and I believe it’s why root motion isn’t working for me (because that bone has no animation information). I’m trying to use root motion to make the character move forward when they perform a dodge roll. However, this armature bone is taking my root bone’s rightful spot and ruining everything. I’ve tried importing this mesh with another filename and tried importing a different mesh with no change. Why is this bone being added?
I’ve tried deleting or removing this bone with no success. Is there a way to remove/delete bones from your skeleton inside unreal?
Actually, yes, only a couple weeks ago. The bone being added is the armature itself. If I move the actual armature while animation inside blender (not a bone inside that armature but the armature object itself), that motion is imported into unreal engine and can be extracted as root motion.
However, now I have the problem of root motion not blending and making movement a lil janky. I have a question open for that.
The solution to the problem of Blender exporting the armature object as the top (root) of the skeleton can be solved by commenting out just two lines from the python script “C:\Program Files\Blender Foundation\Blender\2.79\scripts\addons\io_scene_fbx\export_fbx.py”.
Probably a good idea would be to make a backup of export_fbx.py before making this edit.
Search for these lines of code in export_fbx.py:
else:
# the armature object is written as an empty and all root level bones connect to it
fw('\n\tConnect: "OO", "Model::%s", "Model::%s"' % (my_bone.fbxName, my_bone.fbxArm.fbxName))
This is the code that is adding the extra bone. Comment it out like below:
#else:
# the armature object is written as an empty and all root level bones connect to it
# fw('\n\tConnect: "OO", "Model::%s", "Model::%s"' % (my_bone.fbxName, my_bone.fbxArm.fbxName))
Save export_fbx.py and restart Blender if it’s running. You should not have the extra armature as root bone problem now when exporting skeletal meshes and animations to Unreal Engine 4.
I was incorrect in my previous answer. While all you really need to do is rename your Blender armature to Armature on export to remove the extra root bone in UE4, it is actually still possible to name your armature anything you want and export without the extra root bone in Blender (tested in Blender 2.93.2) if you follow this tutorial:
Hi Nevarim, make sure in your Armature, the Root bone is at the top (the Parent) and all the other bones descend from it. If you have any loose bones that are not children of the Root, parent them to the Root bone (Ctrl+P, keep offset), or if they are just control bones and are not actually used to deform the mesh, make sure “Deform” is unchecked in the Bone Properties for those bones. When you export the FBX from Blender, make sure “Only Deform Bones” is checked in the FBX settings.
As a side note, may I also recommend that if your game contains female characters, always portray them respectfully, fully clothed with modest apparel, no nudity or sensual clothing. This sets a positive example for the people who will be playing your game, and helps establish an attitude of respect for women. A person’s true value is not based on their outward appearance, but who they are on the inside. Too often movies and games depict women merely as sensual “objects” rather than as valuable human beings that God created in His own image. Best regards!
