New vertibird race - Need help with subgraphs and animations (I think)

[ProfPriday]

The idea is to create a new vertibird race with new sounds, with the hope of adding various other aircraft as enemies. I'm basing this idea off M's Abominations mod, who's managed to create a new UFO race with a new model and weapons, but the sounds effects are the same. So if it's possible to change those sounds, this idea could work - if anyone's tried this and found that it's not possible then please do let me know so I can cry in the corner after wasting two days of my life. Additionally, if any of the following is based on incorrect assumptions then please point that out too.

 

Here's what I've found so far:

 

The main files that need to be swapped are the engine audio files seen in this screenshot. These are the propeller sound effects you hear for the vertibird.

These files are referenced in the SDRs seen in this screenshot, with those sound descriptors then referenced in the parent SDR 'OBJVertibirdEngineIdleLPM' in the middle of that screenshot.

Now, the only place I could find a reference for that parent SDR is through a series of HXK file references seen in this screenshot.

 

And that's when things went south:

 

So I figured the solution was to create new SDRs and a parent SDR, then reference them in a copy of the VertibirdBehavior.hkx. Then make that HKX override the default HKX for the new vertibird race. From what I've gathered this is done through a subgraph additive. But, it's how to properly implement this subgraph additive that I can't find enough information on:

I read through the wiki on subgraphs, but it's ambiguous and requires prior knowledge of some concepts.

The tutorials I could find were on weapon animations linked

, and

The threads I could find were on skyrim (link) and this related to human animation link

 

So some aspects I could use some info on are:

 

The role of the 'behavior graph' in both the 'body data tab' and 'subgraph window' of the race menu. Screenshots - For vertibird: link link For new race: link link

The role of the project file, that the 'behavior graph' in the 'body data tab' references - in this case VertibirdProject.HKX

Whether a completely new actors folder, with all copied HKX files needs to be created as shown in the video tutorials, and how this should be done in this case since it's not a weapon.

Whether an additive race needs to be made for the vertibird race or the new race

Whether the VertibirdBehavior.hkx under gameplay>animations is of relevance (screenshot)

 

I've tried a few things based on the above, but this is already a wall of text, so I'll omit that stuff.