I've been a huge fan of Blender, an open-source 3D modeling/animation software application, and I've spent a fair amount of time attempting to create some decent models/scenes. When it came to applying textures, I always felt like I wanted a little more "open-endedness" about the the options I had, and particularly with respect to how they were created. When I started experimenting with bitmapped textures (as opposed to those that are created via various mathematical means), I decided that it would be cool if there was an easy (and more expressive) way to create bitmapped textures that contained the visual complexity that give objects an appearance of believability.
To that end, I used Java to build a prototype. One thing led to another, and then another, and then another... The process is still going, but I decided that it would be nice if others could evaluate and hopefully benefit from what seems like a rather unique methodology- that is, mashing a bunch of pixels together all at once to create some nice visual entropy.
We see this all the time, particularly with objects that have aged a bit - old wooden doors, rusted steel beams, dirt-laden walls and floors, etc. This entropy can often lead to a heightened sense of believability, or realism.
The challenges were to make it easy, and make it accessible. This combination allows, and even encourages, experimentation. I also didn't want to automate the process too much - to that end, you still have a great deal of creative control over how the texture is painted.