Thursday, November 17, 2011

Texturing with Fractal Maps

I am excited to be visiting House of Moves tomorrow! Anyways, on to the Chromakinetics update:

As you can see, the film’s set dressing is almost done. Once I choose an HDRI to work with, I will add some details (Graffiti, telephone poles, pipes, grating, and maybe a…pile of trash or a cat or something?)

However, that’s not what this post is about. No. This post is about something very special to me.



How I Learned to Stop Single Image Mapping and Love Procedurally Generated Blending.

Here is a render from this morning. As you can see, the canal’s concrete looks brand-spanking new. I had to come up with a solution to “grunge” it up a bit. After doing some research, I decided that the best way to do that would be through stuffing the corners with moss and adding streaks of grime along the sides of the walls.

The first thing I did was visit CG Textures and I found a good, mossy canal texture. The only problem is that it turned out looking like this:

The texture repeats itself over and over and over again. It looks jarring, as the human eye can pick up unnatural patterns pretty easily. No bueno.

So to fix this I gathered a bunch of other mossy canal textures and built a layered texture out of them. Then, I attached fractal maps to their transparency so that their appearance would be driven procedurally. Check out my shader network:

Note: All the nodes feed into the layeredTexture node. I just arranged this way to save space.

Note #2: This is a very, very simple shader network. Some shaders done professionally are hundreds (and sometimes thousands) of nodes long.

Phew! I am happy this method worked! As you can see, I added some subtle streaks of grime to the sides as well. Another layer or two of detail and these walls are ready for some graffiti.

Two more shots of the how the city looks so far below: