Nether Seed Map

Reimplements Minecraft's nether terrain density functions, running entirely client-side in your browser. The map renders a horizontal slice at y=31, the lava ocean level. Lava coastlines are detected where terrain meets open lava. Bedrock structure placement uses the MT19937 algorithm in JavaScript; Java structures use the cubiomes library.

When enabled, terrain density is sampled at y=40 over lava areas. Where solid blocks exist above the lava surface, a biome-tinted hatch pattern marks overhanging shelves, bridges, and lips — terrain features hidden by the flat y=31 view.

~88% accurate to vanilla. The remaining differences are nether cave carvers — a post-generation system that hollows tunnels not modeled here. Built using the cubiomes library. A Harrison Bored project.