By far one of the most amazing videos I've seen in a while, this was done by AixSponza. I mentioned them a few days ago and I can't say enough how much I love their work:
AixSponza is a VFX company based in Munich, Germany. They deal with photorealistic animations and use Cinema 4D! Their work has been featured on the Maxon reel for R14 (which is how I found them).
They also share their in-house plugins for Cinema4D.