Configuring Ore Spawning with MMD OreSpawn Library

How Ore Spawn Works

MMD OreSpawn Library is a library mod that gives you control over how ores spawn in Minecraft. Instead of hardcoding ore generation, it reads every .json file placed in the orespawn folder and registers ore generators from them.

Each JSON entry is an object with an optional dimension field and an ores array. When dimension is omitted, the ores apply to the Overworld. Inside ores, each entry describes one ore: the block to generate, plus size, variation, frequency, min_height, and max_height.

These fields control the vein: size sets how many blocks a vein contains, variation adds randomness to that count, frequency sets how often generation is attempted, and the height fields bound where veins may appear.

Because it is a library, MMD OreSpawn does not add ores itself. You supply the JSON, and the mod handles the rest, letting modpacks and datapacks tune ore distribution without writing code.