I tried many options, export/import, even different blender versions, but no perfect result, so I wonder if anyone got the workflow right.
-export/import unreal fbx format: this is the best option, as at least animations are working fine, except the bone orientation is wrong visually which makes it hard to work with the rig
-collada: imported character is fine, however importing animations don’t work well with the character’s hand
-Other fbx formats: skeleton is fine, however imported animations have errors on the mesh, not big, but still unacceptable.
I tried 2.76 and 2.78 blender
help is appreciated!