Level Stem Editor

The LevelStemEditor swaps the chunk generator and/or the dimension type of the already-loaded world at runtime. We don’t recommend using it for production servers, but it can be useful for testing or debugging worldgen.

Caution

Level stem edits are transient, they swap live references and are never written to disk. It is not recommended for production servers. To add or replace biomes in a dimension persistently, use the Biome Bootstrap Registry’s addToDimension / replaceInDimension with the DATAPACK composer instead, or create a brand-new dimension.

How it works

Create an editor with LevelStemEditor.create(), queue the pieces you want to swap, then apply(World) it to each world you want to affect. Only chunks generated after the swap use the new generator. Already-generated chunks keep their existing terrain.

Example Usage

ExamplePlugin.java Java Copy

import dev.wyck.registry.level.LevelStemEditor;
import dev.wyck.worldgen.biome.BiomeSource;
import dev.wyck.worldgen.chunk.ChunkGenerator;
import dev.wyck.worldgen.chunk.NoiseBasedChunkGenerator;
import dev.wyck.worldgen.noise.Noise;
import org.bukkit.Bukkit;
import org.bukkit.World;
import org.bukkit.plugin.java.JavaPlugin;

public class ExamplePlugin extends JavaPlugin {
  @Override
  public void onEnable() {
      // Nether-style terrain and biomes.
      ChunkGenerator generator = NoiseBasedChunkGenerator.of(BiomeSource.nether(), Noise.nether());

      LevelStemEditor editor = LevelStemEditor.create()
          .chunkGenerator(generator);

      // Apply to every loaded world (newly generated chunks use the new generator).
      for (World world : Bukkit.getWorlds()) {
          editor.apply(world);
      }
  }
}

Reverting an Edit

Keep a reference to the editor and call restore(World) to put a world back the way it was.

ExamplePlugin.java Java Copy

import dev.wyck.registry.level.LevelStemEditor;
import org.bukkit.Bukkit;
import org.bukkit.World;

World world = Bukkit.getWorlds().get(0);

LevelStemEditor editor = LevelStemEditor.create()
  .chunkGenerator(generator)
  .apply(world);

// ...later, restore the original generator and dimension type:
editor.restore(world);