Humans, are great pattern recognition machines, who face astonishing amount of complexity on a daily basis. We are so good at dealing with it, that we do not directly register how exactly this happens, yet when something is off, we immediately ‘feel’ it. Procedural modelling is, in a way, like painting, where complexity emerges from the interaction of simple rules. Thus, we can achieve great intricacy and believability from layering the simplest rules if we analyse correctly our own thought patterns.