realtime global illumination - what is the current most used best way?

Crytek has always been at the front when considering cutting edge real-time tech (which -unfortunately for them- is also the single thing they do really well imo) but it sure would be very interesting to see how the managed to implement things. There’s the probelight system complementing SVOGI (and SSDO which they somehow tied into it as well) etc. but how did they manage to re-voxelize a entire level in what, 20 seconds tops or so? Amazing achievement. And the looks…Aaaaargh.