Hi Battz,
Unfortunately I didn’t find any real solution yet. I reported the problem to the blender guys as well, an they said:
‘OK, see the issue… But I think you
are trying to do something that’s
simply not supported by FBX - FBX
assumes a simple parent/children
relationship in transformations, those
Blender’s advanced options cannot be
represented (afaik) in FBX, and simple
transform (and binding) matrices are
not powerful enough to ‘bake’ it
properly. So in a single: this is not
and cannot be supported with FBX
currently. Thanks for the report
anyway.’
Pffff… anyway I am pretty sure FBX could handle the matter so I wanted to test it with Maya. I haven’t done that yet, but it would worth a try.
There is one thing how you can cheat this issue: it only occurs if you have parent-child relationship in your armature. I had a ball character which has legs and I scale the body (ball) part quite often (I only export the deform bones). Since I only scale the body bone I simple made the shoulder bones child of the root instead of the body. Now the scaled bone has no child so the issue does not happen. If you don’t need parent-bone child relationship in UE4 then you can parent all your bones to the root (for me all the deform bones copies the loc/rot/scale of some other bone so the animation remains the same). This is however a really poor solution because this way you can’t use parent-child relationship inside the engine.
PS.: my English is far from perfect so if something is not clear then tell me. 