How Would i add new nodes to animations with out remaking them

That doesn't necessarily work. It can cause exceptions and other undesired issues. At least from my experience.

I'm assuming that you're talking about adding to something that's already compiled into the game. You can make your edits onto your model's node setup in 3ds, and then use the animation importer (http://ghost.halomaps.org/bluestreak/animation/) to import each of the object's animations onto the new node setup. Then just re-export the updated animations and re-compile the animation tag. For first person models you'll of course need the FP arm bones in the scene as well when you import/export the new animations (though not for exporting the new model).

Also, you will need to be careful when importing/exporting animations that you import with all the necessary data and export as the correct format (as a general rule, always import all the data that the importer lets you and export using the same format that the importer states the animation uses).

And lastly, be warned that for some bipeds, recompiling animation tags can/will mess up a lot of the animation tag's settings, and going in to fix them takes a fair bit of knowledge about how bipeds work and is generally a really boring/irritating task.
Edited by teh lag on Aug 23, 2012 at 02:31 PM

thx i needed to know this