Realtime environment within Unity. Mirror reflection from http://wiki.unity3d.com/index.php/MirrorReflection3
Experience with the mirror reflections and the optimization (thanks to unity's frame debugger). 17 mirrors.
I did some shading with shaderforge to minimize the pixelated effect from the reflections of the statues far away.
Something like 100 draw call when we see the whole corridor at once (around 35~40 in the scene, *2 because of the mirrors, and the rest is post processing).
WIP : Still need to do the atlas.