Actually joelbmx made a post in this thread explaining it. basically definition is just joined lines in some kind of pattern so you can actually see the "3d" aspect of the rock.
Too much brush and not enough defining lines. Most of it is just you picking a pattern and putting it everywhere on everything, nature doesn't do that.
Some photos from a solo project that I'm gonna delete because I want to better myself. My process is usually making 100k worth of track, deleting 80k of it, and then repeat ing the process so don't be surprised if you see more.
codrey A full track will take a few months to make realistically. I'm a pretty relaxed person when it comes to this, so a medium sized tree could take 30 minutes to make or longer. If you know me, you'll know I'm a perfectionist in almost all aspects so I see months as nothing.
Lol and then there is me, I make it pretty good the first time, scrap it cuz I think I can do better. Then can never make it as good as my first attempt.