Perlin noise is forty years old and still the most useful thing in our toolbox. Some thoughts on treating randomness like clay.
Ken Perlin invented his noise function for a science-fiction film in the early eighties, because computer graphics looked too clean. Four decades later, it is still the first thing we reach for when an image feels sterile.
Noise on its own is not very interesting: soft grey clouds drifting around. What makes it useful is what you do afterwards. Push it through a sine function and it becomes marble. Threshold it and you get islands. Map it onto a colour ramp and it turns into molten metal, which is exactly how Molten Atlas began.
Octaves and persistence
The two settings we play with most are octaves and persistence. Octaves add finer and finer layers of detail on top of each other. Persistence decides how loud each of those layers is. Low persistence feels like fog; high persistence feels like rock. Most of our looks live somewhere in the middle.
We stopped asking what the noise looks like and started asking what it is made of.
That change in vocabulary helped the whole team. Designers who never write code can now talk about a look being too smoky or not crunchy enough, and the developers know exactly which values to change.
