Physically-Based Rendering (PBR) using Cook-Torrance BRDF for specular.
This is not absolute, by-the-book PBR, because I'm using FUEL's diffuse color textures as-is instead of albedo textures. Instead, it's updating the specular component of the lighting to use more modern models. FUEL defaults to using Phong, but I added Blinn-Phong as an option. However, Cook-Torrance BRDF helps specular light fashion around objects much better.
The C-T PBR specular takes fresnel (view angle), distribution (microfacets) & geometry (visibility) into account when shaping shine around objects. Hence, you see more bright rimlight on the edges of things in the shot above.
An advantage of PBR is you just chuck things into it (textures), and it does pretty much all the work without having to fiddle with too many things. But, I faked some spec & roughness maps, so it did require a bit of tweaking.
But, you end up with better results.