I am trying to export my Blender Rigify Character Rig to Unreal and have a problem.
I get these 3 errors when trying to use the Reatargeter:
Trying to auto-generate a retargeter but no template was compatible with the target mesh.
IK Retargeter could not find target root bone, None in mesh Herath
IK Retargeter unable to initialize target root, ‘None’ on skeletal mesh: ‘Herath’
Root Motion Remap Op, missing target pelvis bone None.
I tried pretty much everything I found online to fix the bone hierarchy but nothing worked.
The imgur video shows the approach that made the most sense to me.
I created a normal Metarig in Blender, upgraded the face and generated a Game Rig with the GameRig Feature Set ( GameRig/README.md at main · Arminando/GameRig · GitHub ) for Rigify. Then I exported it with the settings shown in the video and imported it with default settings in Unreal.
For Retargetting i followed this tuorial from YouTube: https://www.youtube.com/watch?v=XPSKt_sVZek
If I forgot to add any info that would be useful or is needed, please let me know and thanks for your help in advance.
Those errors are all the retargeter telling you the target IK Rig has no root and no pelvis, not that GASP refused the mesh. “None” is an unset bone reference. Auto-generate only fills them in when the skeleton matches a known template (UE5 or UE4 mannequin). A GameRig Rigify export does not, so the wizard bails out and leaves the root empty, and the Root Motion Remap op then fails the same way on pelvis.
Set it up by hand.
Open the Herath skeleton and look at the top of the tree. You want a root bone at the origin whose child is the pelvis/hips. GameRig’s root is often not marked Deform, and “Only Deform Bones” on the FBX export drops it, so the imported skeleton starts at hips and the retarget root really is None. If root is missing, fix that in Blender before anything else: keep a deform root, parent hips to it, apply scale, export with Only Deform Bones, Add Leaf Bones off, primary bone axis X. Reimport. Until that bone exists, Set Retarget Root has nothing valid to point at.
On an IK Rig for Herath, select that root and use Set Retarget Root. Then add chains whose names match the source GASP IK Rig exactly, because the retargeter pairs chains by name: Pelvis (start and end on hips/pelvis), Spine, Neck, Head, LeftArm, RightArm, LeftLeg, RightLeg, and clavicles if the source rig has them. Do not include Rigify’s WGT/MCH/ORG bones, and do not put twist bones in the arm chain. End the leg chain on the foot, not the toe.
The pelvis chain is what the Root Motion Remap op is looking for. “missing target pelvis bone None” means that chain’s bone is still empty. Assign the hips bone on it. Same on the source rig if you had to rebuild that too. The GASP sample already has an IK Rig for the UE5 mannequin; use that as the source, and only build the target.
Create the IK Retargeter from those two IK Rigs, source = GASP mannequin, target = Herath. Skip auto-retarget. Map any chain that did not pair by name. Leave twist chains unmapped if Herath has no twist bones; the main chains will still retarget.
Import scale has to be 1 with transforms applied in Blender. A 100x armature retargets into a stretched pose even after the root error is gone.
Once the target root and the pelvis chain are real bones, those four errors go away and you can retarget. Auto-generate will keep failing on this skeleton, so it is not the path to force.