How to delete twist bones from character but keep the animation to use as unity humanoid rig

robben

Hi, 

I have a big problem and I could not find a solution so far. I got a character as a FBX file. I guess its made in 3ds Max with a Biped Rig with twist bones. And here starts the Problem. My plan is to use the character with the animation type as humanoid so I can change the mesh of the character easily. But I don't know how I can delete the twist bones without breaking the bone hierarchy and get odd deformation of the mesh. Any recommendation, tips or links to some youtube video would be awesome!

fbx opend in 3ds Max 2019


character changed from generic to humanoid animation type


the twist bones destroying the rig


 thanks a lot!

poopipe

The twist bones dont have children that aren't other twist bones. 

Delete them and fix the skinning

Mark Dygert

Off the top of my head, there are a few ways you can go.

Option 1) Ignore them
You could just ignore the twists and not skin too them.

Option 2) Create a new rig
 Screwing with the hierarchy will come with a lot of problems, whoever put twists in the main hierarchy is a dumbass, it wouldn't surprise me if CAT does that, I don't think Biped does. Anyway... with a  hierarchy change you'll need a new version of the rig, so I think you should copy the old, remove the unwanted bones relink whatever is broken and then re-target the animations from the old rig to the new. Motion Builder and Maya HIK are great at transferring animations between rigs of different structures, Max... not so much, but there is a thin path forward with Max.

Option 3) go with biped
It's simple enough to create a new biped based on the current skeletons proportions and copy the skin weights. Hell you might even be able to create a biped in a blank scene and import the FBX file with update animations turned on, it might put the animation on the biped that is already in the scene, provided the joint names are the same. It used to work a few versions ago, I haven't tested it in a while. It's worth a shot at getting it all back onto a biped because...

One of the only cool things about biped, is that it will let you save and load animations between rigs of different structures even if there is a different hierarchy. So you can have one with twists and without and it won't matter, the animations load and save easily. 

Option 4) Fuck it. Do it right.
Personally I like to do all of my rigging and animating in Maya. Max is great and all for modeling, but it's rigging and animation tools are pretty janky. I would use Advanced Skeleton to rig and HumanIK to retarget animations. It's just as user friendly as biped but with so much more flexibility, plus the curve editor isn't a gigantic steaming pile of crap like it is in max.