Raises volcanic cones over an already-generated, already-biomed landmass:
each is a caldera pool ringed by a rim crest, with flanks falling to the
ground the cone stands on and an apron of ash feathering out beyond them.
Runs after biomes so the ash survives the biome pass (which paints
every land cell) and before rivers, which are told to stop at the pool
— a river channel carved across a lava lake is the tell that the order was
wrong. Sites prefer high ground, so cones tend to crown the mountain ranges
rather than stand on a plain, and the rim is always at least one step above
the pool surface so the liquid is contained under the water-surface
convention (floor = surface − 1, see computeWaterSurfaces).
Elevation only ever rises: the cone is laid over the terrain with max, so
a volcano on a ridge keeps the ridge. The caldera is the one exception —
it is dug to exactly two steps below the rim whatever was there.
Deterministic for a given map, options, and rand; consumes no randomness
when volcanoes is 0 or unset.
Raises volcanic cones over an already-generated, already-biomed landmass: each is a caldera pool ringed by a rim crest, with flanks falling to the ground the cone stands on and an apron of ash feathering out beyond them.
Runs after biomes so the ash survives the biome pass (which paints every land cell) and before rivers, which are told to stop at the pool — a river channel carved across a lava lake is the tell that the order was wrong. Sites prefer high ground, so cones tend to crown the mountain ranges rather than stand on a plain, and the rim is always at least one step above the pool surface so the liquid is contained under the water-surface convention (floor = surface − 1, see
computeWaterSurfaces).Elevation only ever rises: the cone is laid over the terrain with
max, so a volcano on a ridge keeps the ridge. The caldera is the one exception — it is dug to exactly two steps below the rim whatever was there.Deterministic for a given map, options, and
rand; consumes no randomness whenvolcanoesis 0 or unset.