Chelsea's MC Worldgen

Chelsea's take on Minecraft terrain lives here: a fast C port of my original Python generator with multithreaded chunk workers, Simplex noise, and just enough chaos to keep it interesting. Consider it about 3/4 vibecoded—the math is solid, but a quarter of the surface area is vibes, instinct, and late-night tuning.

What it does

• Generates chunk data compatible with vanilla region (.mca) files or raw binary dumps.
• Keeps the original Python ordering for noise, terrain, ores, and tree placement so worlds feel familiar.
• Splits work efficiently across threads so you can saturate multi-core machines or scatter jobs in a cluster.

Build it

make

This drops the worldgen binary into bin/.

Run it

./bin/worldgen --radius 2 --threads 8 --out output

Key flags:

• --radius R with optional --center-x/--center-z for quick square patches.
• --min-x, --max-x, --min-z, --max-z for explicit rectangles (great for splitting work across machines).
• --threads N to match your CPU.
• --seed S, --sea-level L, and --format mca|bin for the usual customization knobs.

mca (default) writes region files you can copy directly into a world directory under region/. bin preserves the older chunk-dump pipeline for custom tooling.

Output anatomy

Each chunk blob contains:

1. int32 chunk_x, int32 chunk_z
2. uint16 heightmap[16][16]
3. uint16 blocks[256][16][16]

Chunks are independent, so spray out ranges across machines and merge by simply putting the files in the same output directory.

State of the vibes

• Noise scaffolding is done.
• Decoration passes (ores, trees) mirror the Python original.
• Region writer is battle-tested, but I still keep eyes on biome edges.
• Feature ideas welcome—PRs, issues, or just DM me about the remaining 1/4 vibe debt.