Interface BiomeAssignerOptions

Three thresholds that divide temperature into 4 bands. Default [0.1, 0.3, 0.6].

Three thresholds that divide moisture into 4 bands. Default [0.12, 0.28, 0.85].

Maximum land elevation — used for rock-desert and snowcap elevation tweaks. Default 12.

4×4 biome matrix indexed by [temperatureBand][moistureBand]. Band 0 = coldest/driest, band 3 = hottest/wettest.

4×4 tree-density matrix (values 0–3) with the same indexing. Drives feature layer 0.

4×4 broadleaf-density matrix (values 0–3), same indexing. Drives feature layer 2, and only on maps with at least three feature layers.

Kept separate from treeDensityMatrix rather than folded into it because the two are the same wood seen by different species: conifers hold the cold and the heights, broadleaves the temperate middle. The scatter builder competes per slot between whichever layers are eligible, so overlapping densities read as mixed woodland, and the ratio shifting with latitude is what turns the treeline into a gradient.

4×4 bush-density matrix (values 0–3), same indexing. Drives feature layer 3, on maps with at least four feature layers. Scrub is what stands where it is too dry for a canopy.

Terrain index assigned to submerged (elevation < 0) cells. Default 5 (built-in Water).