To give you some context, in the real world, light bounces from one surface to the other. In fact, when we are indoors during daytime, most of the light comes from indirect lighting, which means that the light (which came from the sun) has bounced more than once before arriving to one’s eye. Indirect lighting is also responsible for very subtle and soft shadows. In short, global illumination is a critical piece in super-realistic rendering.
The technique has obviously been used in movie production for a long time, and recently, games like Battlefield 3 have used global illumination as well, thanks to a middleware lighting engine called Enlighten from Geometrics. It is now clear if Konami came up with its own engine, but the end result is here: they seem to have an interesting proof of concept that works in real-time.
Now, the final question is: how fast is this going to run? At the moment, Kojima-san says that it runs in real-time. However, he does not mention the actual performance in frames per second (FPS). It is fair to guess that this is still very early for performance optimization anyway, and that there is quite a lot of work for the engineering team.
The prospect of a new Metal Gear with photo-real lighting can make many fans salivate, but it seems pretty clear that the next-generation of consoles is getting really close, and this will undoubtedly fuel speculations that some demos will be shown at E3 in June. What do you think of those screenshots?