Nature?s StaircasesNature is not neat and orderly, it is not planned and precise. Nature is a riot of randomness, of conflicting patterns, of inter-species warfare, of storm damage and regrowth.
Bearing that in mind, it is perhaps surprising to know that nature does create staircases, and not just in rock. Every wood or forest of any size will have plenty of staircases, carved out by the trees. If you are recreating nature's work in the virtual, these features are both essential for authenticity, and functional for navigation.
Nature's staircases appear only on hills and inclines. This is obvious if you think about it, as they cut away the existing slopes to form. They make use of the one area of trees and bushes most virtual environments forget all about - the roots.
A tree's roots can spread out just as far below ground as the branches do above. Leaving the roots out of the tree, means you only have half a tree, and you miss out on an amazing array of features these parts can create.
Tree roots spread through the soil, thick roots at first, branching into smaller and smaller roots, binding the soil together. Other plants, growing round the trees or parasiting on the trees if ground cover is sparse, also send roots down. These roots often start spreading out horizontally, just below the surface. On a slope, that means they should - and do - spread out at different levels further up the slope and lower down. They do not spread out parallel, and may twist and turn as bit, but they do run just below the surface.
Over time, rain water washing down a slope will try to wash the soil away. Roots binding the soil hold it in place, preventing this.
If however, that point on the slope is used as a path, whether for animals, or humanoid traffic, then the ground is slowly worn away under paws and boot heels, the more fragile, fleshy roots destroyed over time. People slipping and sliding on wet ground, start to claw out grooves on the slope. These grooves dislodge all except the large, wooden roots of trees, which withstand and stop sliders.
Over time, the disturbed muddy earth dries, and the next rain washes the excess away. As more time passes, a groove begins to form, between each half-exposed tree root and the next one down. A crude step begins to take shape. It is protected from hollowing out too much as the tree toot stops the soil slipping, and so debris builds up in each step and mulches down, making it less slippery when wet. A crude stairwell has formed in the slope.
Some steps will cut right across the path, mostly straight. Others will cut partway across, then disappear as the roots forming them turn sideways and burrow into the hill. More often than not, you end up with a staircase in which people must cross from one side of the path to the other and back again, as they ascend it. Never the less, they can easily ascend and descend, without hanging on to things. For these, are nature's staircases, and become a major thoroughfare for the wood.