What it is
Region Output packs a biome, an optional appearance and placements that only happen inside the region. Choose Region splits the world between regions.
Made by2
Used by2
Good to know
Same biome, two regions
Two regions can use the same biome and still get different looks and placements.
Splitting
Choose Region compares a density with a threshold at every X, Y and Z. Regions pick between recipes; they don't blend terrain.