Hexagon Concrete Tiles, based on a photo I took in Portland, OR.
I took a different approach on the twigs, leaves, and the cigarette buds. I made them in Designer and manually moved them closer to the edges of the concrete tiles.

Side Story: I took this picture the day after I got laid-off from Vertex Solutions/Adayana Government Group. I took a BoltBus trip down to Portland, OR the next day. This was in early January 2016. I worked on this material while I was working at Hardsuit Labs in the middle of 2018, just to try this out.