I've been doing a bit of research into Realtime Global Illumination. It's Kinda a hobby of mine, reading various white papers and watching tech demos even if I can't really understand too much of the technical programming aspects.
I got a feeling that UE4 is using Geomeric's Enlighten for their realtime radiosity lighting based on a lot of their GDC 2012 videos using UDK
and their deep integration into the engine. Although I guess Autodesk/Illuminate-Labs Beast is the same way, but those guys aren't dooing the same thing, e.g. realtime/runtime GI.
Anyway, if it is Enlighten or something similar, I hope it doesn't take as much manual setup and preprocessing as their 'Maya plugin workflow' video suggests
. I guess it still produces better results than Cry3's LPVs, and is faster and more realistically achievable than voxel cone tracing, even in it's current form.
I am hoping that UE4 will be able to get some sharper/higher-res GI than the really low-frequency broad GI that Enlighten appears to produce in realtime, or that they at least couple it with some good Screen Space Directional Occlusion to fill in those details:
Enlighten Realtime Preview GI:
Baked GI (Also done with Enlighten!):
Either way, I CANT WAIT to get my hands on some Real-time GI tech. Crysis 2's was fun to play with to say the least.