Problem when importing FBX rigged using Advanced Skeleton - Missing geo

Rigging
1

hello everyone,

i’m new to UE4, currently having export-import problems from Maya 2014 to UE4:

in Maya, the character geometry isn’t a single mesh geo, but consists of lots of geo fragments like this hierarchy:

[ul]
[li]Geo_Mesh_group
[/li][li]geo_group01
[/li][li]geo01a
[/li][li]geo01b
[/li][li]geo02
[/li][li]geo03
[/li][li]geo04
[/li][li]geo_group02
[/li][li]80 geos
[/li][li]geo05
[/li][li]geo06
[/li][/ul]

for rigging, I used Advanced Skeleton autorig plugin. it automatically created hierarchy as follows:

[ul]
[li]Group
[/li][li]Main
[/li][li]FitSkeleton
[/li][li]MotionSystem (FK + IK joints, controllers)
[/li][li]DeformationSystem (default bind joints + additional facial bind joints + accessory joints)
[/li][/ul]

when i finished rigging and skinning and tried to export the fbx, there were Maya warning and error messages as follows:

Exporting T-Pose FBX (‘Animation’ unchecked):

Warning: Complex animation baked (1) 537 attributes had complex animation. Complex animation was exported as baked curves. (112770 evaluations done)

then I ignored it and continued importing the FBX from UE4, which gave me warning messages:

when importing Skeletal Mesh (the T-pose FBX):

Multiple roots are found in the bone hierarchy. We only support single root bone. Multiple roots found Import failed.

when importing Animation FBX:

Imported bone transform is different from original. Please check Output Log to see detail of error.

the final results:

[ul]
[li]head geo is missing, but hair geo, which is a separate fragment, isnt.
[/li][/ul]

i had posted this question on ue4 forums, but someone said it’s actually Maya’s FBX issue.
so how do I fix these issue? your suggestion is appreciated with thanks.

2

Are you exporting the whole scene or carefully selecting only what you need and exporting the selection?
FBX will export far more than a game engine needs by default.
for the base rig only export the meshes and the bones that they are skinned to.
for the animations export only the bones.

everything else is useless to a game engine (unless you are exporting blend shapes or dynamics)

3

[QUOTE=Mambo4;25590]Are you exporting the whole scene or carefully selecting only what you need and exporting the selection?
FBX will export far more than a game engine needs by default.
for the base rig only export the meshes and the bones that they are skinned to.
for the animations export only the bones.

everything else is useless to a game engine (unless you are exporting blend shapes or dynamics)[/QUOTE]

thanks Mambo4,
I selected only the binded/skinned bones, baked the animation and exported only these skinned bones and the geometries.
I left the other (FK/IK) bones and controllers unchanged.
do I need to delete the rest before exporting to FBX?

4

Well judging by the import warning, the skeleton may not be UE4 compatible.
It’s possible that the Advanced Skeleton autorig plugin is simply not compatible with games or Unreal.

you could try adjusting the skeleton and trial and error to get something that works
but that probably means you’re redoing the animations too.
and if that’s the case, Unreal has its own suite of rigging tools for Maya.
you may as well start over with those.

5

[QUOTE=Mambo4;25599]Well judging by the import warning, the skeleton may not be UE4 compatible.
It’s possible that the Advanced Skeleton autorig plugin is simply not compatible with games or Unreal.

you could try adjusting the skeleton and trial and error to get something that works
but that probably means you’re redoing the animations too.
and if that’s the case, Unreal has its own suite of rigging tools for Maya.
you may as well start over with those.[/QUOTE]

Thanks Mambo4, I’m aware of Unreal’s ART plugin, but for some reason, my animation team decided not to use it in the production.

Btw, I did trial-error with Maya FBX export and UE4 import settings and got better results.

Maya FBX export:

  • Smoothing Groups ON
  • Tangent and Binormals ON
  • Preserve Instances ON
  • Convert NURBS surface to: NURBS
  • Bake Animation ON
  • Deformed Models ON
  • Deformed Models Skins ON
  • Deformed Models Blend Shapes ON
  • Input Connections OFF

Result:
Warning: Complex animation baked (1)
12 attributes had complex animation. Complex animation was exported as baked curves. (2520 evaluations done)

UE4 FBX import:

Skeletal Mesh:

  • Normals: Import Normals
  • Import Rigid Mesh: OFF
  • Use Time 0 Pose for Ref Pose: ON
  • Preserve Smoothing Groups: ON
  • Import Meshes in Bone Hierarchy: OFF

Result:
Error Skeleton has non-unique bone names.
Bone named ‘polySurface1’ encountered more than once.
Error Import failed.

I ignored the error and warning messages.
The character geometries and animation are now fully imported, except there is a minor geo deformation issue; some vertices seem like not skinned.

Thanks again, Mambo4.

6

Hey guys! Im bringing this thread back from the grave in case someone googles this. I found this from googling and while I didnt have the exact same problem, its very similar. When exporting the skeleton and mesh, I noticed all the other groups also ending up in Unreal. No idea why but things seemed to work so I was like whatever. However, I ran into serious problems trying to use root motion on animations because Unreal was treating the main rig group as the first bone, how i fixed this, is I went into my main rig file in maya, and just middle mouse dragged the actual in game skeleton and the geometry out of the groups entirely and put them by themselves and then reexported that into unreal as my reference skeletal mesh. My animation scenes are all referenced, and it seemed to have no affect on those animation files in maya, cool. After reimporting the main skel mesh into Unreal, I got a nice clean hierarchy, also cool. But all my animations in Unreal depended on the messy hierarchy and while the engine did its best to retarget, all my animations were misoriented, not very cool. So now its my job to go into each maya scene file, that now contain the correct hierarchy i mentioned before and simply reexport them, bringing them back into unreal fixes the orientation problem and I don’t get that “Imported bone transform is different from original” as I was getting before. SO, to recap if you are using Advanced Skeleton, save yourself the headache and restructure your rig file and get the skeleton out of those groups, before you even start animating.

7

YOU !!! You have no idea how you saved my life by writing this. I’ve been spending the last two weeks creating modular rigs for a cross-platform game using Advanced Skeleton and I realised today (my deadline) that no animations went through Unreal. I was litteraly on the verge of breakdown because nothing worked, even though the rig was imported fine.
I got the rig out of the groups, exported it cleanly with the geo and the settings written above. I baked my animations before export then exported only skeleton. Miracle. No Errors.
Unfortunately, like you said, you lose all your animations BUT I had just made the run for now so THANK YOU !
I would never have guessed this was the “skeleton in group” situation here.
:pray: :pray: :pray: :pray: :pray:

8

Instead of moving the game rig out of the groups in Advanced Skeleton, you could duplicate your Advanced Skeleton rig and delete everything except the skinned joints and the meshes to create the clean game rig. Then you can reference in the animation file that uses the Advanced Skeleton rig, constrain the corresponding joints of the game rig to the Advanced Skeleton rig, bake, and export just the game skeleton with the animation clips. So has long as you have the same clean and properly skinned game rig, you could build whatever control rig gets the best animation result and even use multiple control rigs for different animations.