So I imported the idle animation Mannequin file into Akeytsu and Modo. The model ends up looking broken Does anyone know exactly what causes this?
Akeytsu
Modo
it looks just the same in blender. But it did not create any problem for me…
Hello, I don’t know what causes this but I had the exact same issue in Blender on the exact same left shoulder, right foot and forearm. Inside of Unreal itself you need to set the BONES to use the SKELETON and not the ANIMATION. I guess it offsets some of the positions. I have a tutorial where I do character animation and fix a similar issue. Have a look at the video it should help you solve the problem. https://youtu.be/DKfOaIXCN90?t=641
If you look at my earlier videos you will see that I have a character running around with the same deformations.
Switching everything to skeleton doesn’t fix it for me, I’m trying to import into Akeytsu.
I don’t really wanna necro this, but I have a similar situation.
EXPORT animation from UE4, import into Modo, arms are twisted up in a horrible way.
Looks like its something to to with the bones upperarm_twist_01_ and lowerarm_twist_01_ (l and r)
An example can be seen here:
https://www.youtube.com/watch?v=XHId9h80c94
Any Modo experts shed light on this, offer some correction?
Has nothing to do with what you import with.
It’s the UE4 animations that are damaged/broken and are literally only held together in engine by the runtime retargeting system that sets all the bones to “skeleton”.
If you manually change all retarget settings to Animation you’ll see the same issues across the board in engine as well.
EPIC has been told to fix this only about a million times from just about as many users. They simply DGAF.
So …what?
Ditch the idea of using the Epic anims as a starting point?
Ditch the Epic skeleton completely and just use whatever I feel works?
Perhaps I’m labouring under the wrong ideas, but those upperarm_twist_01_ and lowerarm_twist_01_ bones just seems wrong to me anyway.
I would have placed them INLINE with the rest of the arm bones, e.g. lowerarm_twist (which I would call WRIST) should be attached to the lower arm (duh) and then the hand would attach to that.
You know, like a chain of bones.
But both hand and lowerarm_twist are parented to the same bone, lowerarm.
This to me seems weird, but is even worse on the upper arm, where upperarm actually controls the lower part of the upper arm, and its CHILD upperarm_twist controls the shoulder.
Perhaps this is just my inexperience of game character rigging, and I’m certainly open to constructive correction on these things.
You can try to place them twist bones in line, and if you get to IK setup or physical animation you’ll quickly see for yourself why that’s a huge NO.
Basically you just made all your characters and related animations a version of Gumby and will need to start over.
Twist bones really only work if they are paired to the parent and unrelated to the actual chain.
Guess I just saved you a month of work didn’t I? Tsk. Tsk.
As far as the “so what”.
You can try to retarget the animation to a copy of the same skeleton.
That may just “bake” the correct position - fact which obviously Epic refuses to think about. It would take them maybe 5m to fix the set of animations that come with the base templates… too much work… 
IMHO, always make your own. It’s easy. You’ll learn stuff along the way. Including anatomy.
As far as thw twist bone managing the “wrong” thing…
Is it?
Grab a Genesis 8 and check it’s rig. See what does what. They put a lot of time into it, so I would think they got it right.
Remember that when you twist a round mesh over 90deg you get a choke point somewhere, even with Great armor paint.
The twist bones are there to Fix that when it happens (all the time if you twist bones beyond the humanly possible…)