Metal and Ambient Occlusion
I've spent a LOT of time on the look of metal lately. Finally, I've managed to make ships look like they're made of metal!!! This is the first time I've ever had any success with metal BRDFs (even in my offline rendering experiments). I think the main key that I was missing is that the distribution really needs to be exponential rather than power-based to look convincing, otherwise the surface looks like plastic. Another key is to modulate the specular amplitude in some interesting way (just modulating it with albedo looks great).
On top of good metal shaders, I now have new-and-improved SSAO in the engine. Together, the metal and AO are making my ships look better than ever before! In addition, I think I'm finally getting closer to a good procedural ship algorithm. It's taken forever, and I'm not there yet...but I'm getting closer.
Here's a cool shot that I took tonight. This has a bit of post-process on it for dramatic effect; I wanted to use it as a wallpaper. Still, you can get a nice sense of the metallic surface.