Ah, I'm talking about the actual animation track (got the bones proper, I use a bone, and then a 0-sized bone in anim8or). I'm not sure about spec, I use the FBX SDK api, but FBX is stored as relative offsets by joint, and each rotation at a joint is Euler X Y Z (in that order). The translation to and from anim8or of skeleton I have working. It's the animation keyframe tracks that I am trying to convert. In FBX, each joint rotation is stored in euler angles are not relative to the bone, they are normal, unlike anim8or which appears relative to the bone, which appears to me to be 3 angle rotations, of a coordinate axis aligning with the bone (essentially, transformation of (0,1,0) into bone orientation), which seems like multiplication of 3 axis-angles or something.

I don't see it in SMDA2Anim8or, but it must be in the bvh one somewhere, the angles of the animation at each joint, into anim8or format

For example, a 0-sized bone with absolute resolved orientation quaternion of:

x 0.52577096

y 0.084030904

z 0.40771002

w 0.74180597

, and euler rotation 58.6767 33.600 138.3259 in FBX. That translates to in anim8or 30 60 40 (this is goal, to find out these numbers using math for general case). Well, the part I am trying to figure out is how to automatically go from those Euler angles, with known orientation that I already figured out, into anim8or animation angles.