To be honest, most of the components of VATS already exist in Oblivion mods: Deadly Reflex has locational damage effects and dismemberment, http://www.tesnexus.com/downloads/file.php?id=30973 has a "stop time" spell that allows you to stack spells and arrows, http://www.tesnexus.com/downloads/file.php?id=30437 has a slow motion "kill camera" and doing it in third person would require using "CreateFullActorCopy" where the player would be, and randomising the kinds of kill camera (to the OP - this might be a good mod for you, btw), and http://www.tesnexus.com/downloads/file.php?id=29429 has damage counters that spill out of actors to show how much damage you've done. "GetCrosshairRef" allows you to tell what you are pointing at. The maths component should be relatively simple to script, I mean, the damage formulae already exist, and doing distance checks and crude ways that enable you to determine how large a target is, would help you work out the probability of hitting. The glowing highlighting of targets could be done with magic shaders. The only particularly tricky thing would be the zooming in, and the "clicky" movement of VATS, but the former could be achieved by moving the player around. It's just a matter of merging all of these different aspects into something that resembles one of fallot 3's unique selling points
So it's only a matter of time. I just doubt it will be me making it because I have a very large project I'm still working on (see my sig, plug plug
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