The Camelot Unchained site has been updated with a new post that goes into detail about the new environmental lighting and how it is created. The discussion begins with a discussion of how light is applied and perceived in real life and then goes into how the team is trying to replicate nature within the parameters of a game engine.
Camelot Unchained with utilize something called "cube map light probes" that essentially take a 6-panel image, wraps it around a cube with dynamic lighting applied by making every pixel into a light source for correct application. This is all accomplished on the fly, though developers are working to keep it optimized to reduce load.
And finally, we get smart about what things really need to be rendered in the cubemap. Seeing one enemy character on a faraway hill is really important to gameplay, but it’s not an important part of how light shines on you. Likewise, particles can frequently be eliminated, as can grass and lots of brush. Models used in the game generally come in several “levels of detail,” ranging from tens of thousands of triangles when you’re up close, to a few hundred far away. The low-detail faraway version is plenty great for lighting. The most important objects are the sky, the terrain, and the major nearby buildings, and the result is almost always good enough -- and more importantly, fast enough to support the large battles at the core of Camelot Unchained.
Read more on the Camelot Unchained site.