/3/ - 3DCG

>>360126
>>360128
Maya 2012 & mental ray

>>360204
It's really a babby tier setup, in maya you can establish physical sun and sky with one click, render settings. Final gathering does the bulk of indirect illumination, because it's rays bounce off the sky sphere. I added single light to emit photons - they bounce off the surfaces carrying colors - color bleeding - It's faint but definitely there, "warming up" the scene. Pic related, just changed the blue back to gray.
I think you can achieve great result with just one, pohoton emiting light, placed in the window for example. Check this links, they're step by step.
http://www.tokeru.com/t/bin/view/Maya/GlobalIlluminationIllustrated
http://www.interstation3d.com/tutorials/mray_gi_rev1/mrayGI01.htm