Anyone know of any information on how they did the body mechanics in fatalities for the game?

They look really good, I know they are done in an modified Unreal Engine and the team studied trauma for so much that some had to go to therapy. But, I really want to know is what did they do, it's it all a bunch of separate body parts? Do they swap out bits after damage is incurred?

Or do bodies completely swap out after damage?

Are the fatality bodies different than the ones we control?

Etc...

(I'm curious as I always wanted to make a realistic medical game and even though MK is way more gorey than real life. It makes me hopeful that maybe a realistic trauma game could be created.)