Hello,

I am doing export work from Blender to DX.

According a book(Frank Luna DX11) it needs animation data, it wrote: Each key frame stores the time position, the translation vector specifying the position of the bone, the scaling vector specifying the bone scale, and the quaternion specifying the orientation of the bone.

What is the definition of the position of a bone?

The book is not say any more about the position. In Blender's data, I found it's bone has head, tail, center position, which one is for the animation data do translation vector work? or arbitrarily?

Thanks.

Generally the bones translation (the translation you store, lerp) is local/relative to the bones parent bone, if there is no parent bone its local = world. You would transform a bones local transform by its parents world transform to create its world transform, and then use the result for skinning.

As for blenders terminology Im not sure, local = tail? maybe? I find the term bone confusing, it implies two end points, when modeling packages tend to view them as transform nodes with an optional parent node. Nothing says you cant have a single bone-node-transform, attach a model to it and animate it.