They’re axis rotations. { angle } is equivalent to:
<Rotate> { angle 1 0 0 }Keep in mind that the order in which they are applied matters - look in the FBX specification in which order the transformations are supposed to be applied.
Good luck! Figuring out how all the transformations fit together can be challenging, especially for animated models. It’s the reason why I never managed to add animation support to dae2egg.
(In fact, if you run into trouble, there might be something to learn from the questions David answered for me during my adolescent attempts.)
The comments basically contain a list of the joints that that vertex is a member of with the appropriate membership value. They’re just comments; useful for humans reading the .egg file, but ignored by the .egg loader.
Yes, each joint should reference each vertex that has membership. This sounds like this could be a lot of vertices, but in practice, this usually doesn’t turn out to be all that many.
No, that doesn’t matter. It’d just be a file size optimization, as you suggested. If you’re worried about that, you could always pass it through egg-trans with no options, just to parse and write out your .egg file (it will also add in those funny group-ref comments).