Very little project...
The first render is done using SLG2 devel5 (40min on a GTX 460), the second one is made with LuxRender (big image: about 2kS/p in ca. 4h).
I uploaded the model to blendswap.com (the version with the LuxRender materials).
edit: Blendswap link: http://www.blendswap.com/blends/archite ... d-bubbles/