Did not read it all, but looks your problem comes from nonuniform scale, which leads to skewed, non ortho normal child frames if not treated individually.

I don't know how Unity handles this, but most 3D modeling software does not propagate skewed matrices down to the children. Instead they propagat…

I did it.

Kylotan and Juliean have already given great advise.  They also have helped me several times when I have questions here.

I still want to add some more …

To handle child-parent transform, I use the similar approach as Ogre3D.  My gameplay has to be split into 3 phases :-