Ehm... I just noticed that you should uncomment the code that I have commented for animations only. market a little bit to much of it D:
(Just setupRotationAngles is for animations), And instead of just

this.BodyCenter.render(scale);

This should be done for every element except you want to add ...

Ehm... took a look at it and nope, Minecraft doesn't allow half cubes (unless I and a giant amount of other modders missed something)
However I noticed there is an other vvariant of this method that might be even better.

addBox(String partName, float offX, float offY, float offZ, int width, int ...

It wouldn't be an easy way, but... would it be ok if somebody creates a mod work space where you have just to paste the code to be able to test it?

Json Files.

Ok, does somebody maybe have a version of a model for 1.8 and 1.9+?
(If possible with relativly same ingame possitions) I need to know what the differences are so I can make it.

Ok, as this has been asked for so many times and it hasn't been added yet I want to make you a suggestion:

Somebody tell me the exact differences between 1.8 and 1.9+ Models and I will try to make a parser for them.

@Sphax I think the best for this would be to make it more of a raw format and giving users the possibility to add a template where the raw data is pasted into.
like for a template:

%originX%, %originY%, %originZ%, %width%, %height%, %depth%; %offsetX%, %offsetY%, %offsetZ%, %rotX%, %rotY%, %rotZ ...

Location: Preview :preview:
Option name: Animate
Option type: Radio-box (multiple choice)

Option action when enabled/disabled/clicked:
Add the 4 Main Animations of a player considering Items.
Containing Drinking, Eating, Bow Pulling and Blocking.

Mainly because that might be useful to ...

The blade seems way to thik compared to the handle. but I guess you made it using voxels? So it cannot be changed.
But otherwise I like it ^^

Edit: The shading seems to carefull and might be a little bit stronger at least I haven't noticed that there is any shading before I zoomed in.

Thats all already possible. At least the rotation and the optfine element export.