Caverns, Automata and the Meander Revisited

Sun, 09 Jun 2024 00:00:00 +0000

Back in 2015 I tackled automata generated caverns for a 7DRL, and in 2018 I wrote up the meander algorithm for rivers. Both made it into compass and both got a little sharper along the way, so I wanted to revisit them with the actual implementations in hand.

Caverns

The cavern generator is Conway’s Game of Life pointed at a terrain problem. It’s almost embarrassing how little code it takes.

Clone the map and randomly seed roughly 55% of it as floor.
Run a single Game of Life pass over the Moore neighborhood (the 8 surrounding cells). An empty cell is born as floor with 5 or more floor neighbors, and an existing floor cell survives with 4 or more.
clipOrphaned keeps only the largest connected blob so you don’t get a dozen disconnected pockets.
Build walls around everything walkable and force the map border to wall so the cave is sealed.

One pass is enough. The birth and survival thresholds are doing the smoothing that I used to iterate several times to get, and the result is the lumpy organic cave you’d expect.

Caverns on Nathaniel Inman

Caverns, Automata and the Meander Revisited

Caverns