What do you mean you can't find any of the HRC files that contain the multiple references to the RSD files? There are so many!!!
Here's a list of some of them:-
aggb
gjeb
gchc
fgfb
epfb
azbb
aihb
ahdf
aiba
gwaa
fiba
fhaa
eyie
atfe
asjc
When I said
"The 2 can be changed into anything else corresponding to the amount of parts added."
I meant that you can reference one or more RSD files but you must first specify before hand how many RSD files you wish to attach to that "bone".
For example let's take the file aggb.hrc
chest
hip
4.551412
2 AGGE AGHA
Notice the number 2? This shows that two RSD files are referenced at this bone.
Basically, it means that the section "chest" is attached to the section "hip".
The number 4 here on the other hand is the distance that chest is from hip.
I not too sure what the numbers after "." represent cause I didn't see any difference after changing them.
Let's take another example of the file eyie.hrc
bone_2
root
58.32005
6 EYJB EYJD EYJF EZAB EZAD EZAF
See the number 6? This shows that 6 RSD files are referenced at this bone.
This section bone_2 is "58" units away from the root position. So, basically the numbers before the RSD references only show how many RSD files there are referenced.
Let's say I put this:-
bone_2
root
58.32005
0
bone_3
bone_2
0
1 ABCD
This would make a section called bone_2 appear "58" units away from root but since 0 RSD files are referenced, there will be nothing displayed on screen. In the 2nd section you see that a section called bone_3 is attached to bone_2 with a distance of "0" units. Now bone_3 has a reference to ABCD.RSD. This would make the object ABCD appear "58" units away from root. Get it?
You don't have to match the amount of RSD files referenced with the number of bones specified in the header. Why? Cause their both different things!!! The number of bones specified in the header only needs to be matched with the amount of bones in the HRC file. The "bones" are the the sections bone_2 and bone_3 in the example above. Theoraticaly, you could join all the RSD files in one bone but that wouldn't be the point would it? After all you don't want Cloud to be walking like a stone, right?
You won't see many files that have more than 1 RSD referenced to a single bone (especially humanoid creatures) cause it limits movement. The only reason you would want to use it is to cluster certain objects together like lets say, Aeris' ponytail and her white materia. Note that when you reference multiple RSD files from the same bone, all of them will originate from the same spot thus making it very messy unless it was meant to be like that in the first place.
As for you question on what is "root", I believe "root" is the centre of the entire 3D object since the hip is usually referenced to it. So, you should start building all your 3D objects from "root".
That's all I have to say for now. Does that answer you question Srethron?
If you need any more help feel free to ask. Do you need me to write a complete document about the HRC format?
I gotta study for my programming exam tomorrow so till then, bye!