importing bones via FBX to blender - the axis thing

rollin

Hi everyone!

So I'm looking for the best way to send bones from max to blender. But it seems to boil down to a more generic thing: how to get bones into blender.
The issue is that the bone orientation in blender seems to point always in Y-direction. So if you want to have a connected bone system all these bones need to face in Y-direction. 
Is it just that? Deal with it? I think I can - with bone retargeting and stuff - but if I have missed something pls. let me know!

cheers

InfraCrimson

Found this on a help forum

Enable all these options while you import:

• Import User Properties
• Import Enums As Strings
• Ignore Leaf Bones
• Automatic Bone Orientation

rollin

But this still ends up with wrong bone orientations, isn't it?
It looks right but if you export this back to fbx it will not end up the same

InfraCrimson

Phew, beats me. Sorry there

pior

Well, the way to think of it is to consider the visual representation of the bones as just that - a visual representation. Therefore you can just ignore the fact that the lines shoot out to the sides, and it will re-export just fine.

Now of course if you need to rely on any tool operating on the assumption that there is a "main" axis/orientation, then you'll run into obvious troubles. For instance you likely don't want to animate the armature directly. But as far as in/out operations you'll be fine.

However you do need to play close attention to the very top of the hierarchy (structure wise, and naming-wise) as you might run into cases of Blender adding an extra root bone on import and/or renaming the existing one. Can't recall in full detail, but I've had to do some editing on skeletons in that regard so that they re-export *exactly* as imported. Might have been caused by a bad setting on initial import though, not sure. It's definitely workable though.

rollin

Yea @pior I guess what I'm missing is the view-as-links mode from max.
Anyway blender can do a few other cool tricks instead. 

• So I created a completely new rig, aligned to the bone rotation points of the imported one. I used the visually-correct imported rig as reference (but the axis-correct for re-exporting to the game).
• Then I created a copy of the deformation bones of the new rig as helper armature. I have a script which does this automatically with all required bone constraints. So the bones move with the helper rig. 
• Then I renamed these copied bones to match the bones I imported.
• Now I can link the model to the copied bones armature for working with it in blender and just for exporting I link it back to the axis-correct imported armature.