Fall Mill was one of the environments I created while attending Ex'pression College for Digital Arts, and it was based on background art from the show Samurai Jack. The goal was to emulate the hand-painted canvas feel and the unmistakeable "Genndy" aesthetic. The challenge was to find a way to achieve the compositional quality and detail of Paul Svoboda's Hand-Painted Hobbit House... without contracting pneumonia in the process.

The pipeline I ended up with allowed me get the look and feel that I wanted with only a handful of textures. Meshes were made simply and quickly, which also helped match the aesthetic goal. Most meshes were simple boxes or cylinders with a little bit of randomization. UVing was very easy, because the source art featured lots of harsh edges that already resembled UV seams.

The key to success with such simplicity was vertex coloring and gradient mapping. This was inspired by Andrew Maximov's "Ditching Diffuse Maps." One vertex channel was painted to represent the curvature of the surface. I called it Edge-Cranny before I learned it's usually called a convexity map. Values 0-1 represented concave to convex. These could be used to blend dirt and wear on surfaces according to their geometry. There are no mesh-specific textures.

Each texture consisted of a tiling normal map and a height map. I developed a unique lighting model that took influence from the normals and convexity and blended them with the height map, which then mapped the color gradient. I also created a function to create new color gradients within material instances, but 256x1 color gradient textures do help with optimization.

I am very pleased with how this turned out. An unintended but surprisingly useful side effect of this technique was that I was able to use UDK's vertex painting to influence the color map on virtually any area of the environment. It felt extremely  powerful to be able to control the lighting with such precision, as if I were painting a picture with just a stroke of my mouse.