Hi!
After sitting in front of an concrete wall every day, I thought I should bring my observasion into maya
Just kidding... some institutes here at the local university are just a concrete box... that's where I got the idea to create this image. I took some reference photos and created this in maya with an lightning pass, an occlusion pass, an edge pass and 2 texture passes and some grunge passes to mix it all together into one image.
For lightning a used a 10 degree spot with cie setup and quadratic falloff and raytraced area shadows. Rendering time for all passes together lower than 10 minutes with final gathering in lightning pass.
-Klaus

ps.: here's an higher res