If someone from Terasology is willing to trade, I will build Terasology and hack on it a bit. By "trade", I mean build my code and run the demo. Certainly we should talk. I have learned quite a bit from Minecraft and related projects. At first I was amazed at the landscapes and the seeming occlusion culling -- since I didn't know about the surface extraction. Last year I worked on a hybrid tracer/rasterizer http://code.google.com/p/xolotl-hybrid/ before deciding to return to a pure tracer. Maybe I should resurrect that and show it to you.