Box projected cube environment mapping BGE

box projected cube environment mapping in Blender Game Engine.
bpcem shader by Bartosz Czuba. (http://devlog.behc.pl/)
This scene has 3 baked cube maps – 1 for each room. No light sources. As lighting and reflections are baked, the shader is incredibly fast and can even be used to create convincing indirect lighting with color bleeding.

The environment is made with Cornell Box in mind. and some inspiration from Mirrors Edge.
Huge thanks to Bartosz Czuba for tips and help getting this work in BGE.
thread in BlenderArtists: http://blenderartists.org/forum/showthread.php?t=209688