[1.16.4] [Solved] Custom Chunk Generator Issues

I am currently working on an entirely server side mod that adds a new world type with its own unique chunk generator.

So far the chunk generator works as expected when I load a world for the first time, but if I load the world after closing it, all new chunks are generated with the default overworld chunk generator. In addition, loading these worlds for a second time results in the experimental settings warning screen being displayed.

I am not sure what is causing this behavior, but I suspect it has something to do with my chunk generator's codec (which I still do not fully understand the functionality of) due to this error that I get when loading a world for the first time:

[23:22:20] [Render thread/ERROR] [minecraft/Minecraft]: Error reading worldgen settings after loading data packs: Unknown registry element RegistryLookupCodec[ResourceKey[minecraft:root / minecraft:worldgen/biome]][xmapped]
[23:22:20] [Render thread/ERROR] [minecraft/ServerWorldInfo]: WorldGenSettings: Unknown registry element RegistryLookupCodec[ResourceKey[minecraft:root / minecraft:worldgen/biome]][xmapped]

Here is my chunk provider class:

package planetoids.world;

import java.util.ArrayList;

import com.mojang.serialization.Codec;

import net.minecraft.block.BlockState;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.math.vector.Vector3d;
import net.minecraft.util.registry.Registry;
import net.minecraft.util.registry.RegistryLookupCodec;
import net.minecraft.world.Blockreader;
import net.minecraft.world.IBlockReader;
import net.minecraft.world.IWorld;
import net.minecraft.world.biome.Biome;
import net.minecraft.world.biome.Biomes;
import net.minecraft.world.biome.provider.SingleBiomeProvider;
import net.minecraft.world.chunk.IChunk;
import net.minecraft.world.gen.ChunkGenerator;
import net.minecraft.world.gen.Heightmap;
import net.minecraft.world.gen.WorldGenRegion;
import net.minecraft.world.gen.feature.structure.StructureManager;
import net.minecraft.world.gen.settings.DimensionStructuresSettings;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;
import planetoids.util.Planetoid;
import planetoids.util.PlanetoidsHandler;
import planetoids.util.PlanetoidsUtil;

public class PlanetoidsChunkGenerator extends ChunkGenerator
{
	public static final Codec<PlanetoidsChunkGenerator> codec = RegistryLookupCodec.getLookUpCodec(Registry.BIOME_KEY).xmap(PlanetoidsChunkGenerator::new, PlanetoidsChunkGenerator::getMainBiome).stable().codec();
	private final Registry<Biome> mainBiome;
	
	public PlanetoidsChunkGenerator(Registry<Biome> biome)
	{
		super(new SingleBiomeProvider(biome.getOrThrow(Biomes.THE_VOID)), new DimensionStructuresSettings(false));
		mainBiome = biome;
	}

	public Registry<Biome> getMainBiome()
	{
		return this.mainBiome;
	}

	protected Codec<? extends ChunkGenerator> func_230347_a_()
	{
		return codec;
	}

	@OnlyIn(Dist.CLIENT)
	public ChunkGenerator func_230349_a_(long p_230349_1_)
	{
		return this;
	}

	public void generateSurface(WorldGenRegion p_225551_1_, IChunk p_225551_2_)
	{
	}

	public int getGroundHeight()
	{
		return 0;
	}
	
	/**
	 * Generate the blocks in a chunk.
	 */
	public void func_230352_b_(IWorld world, StructureManager structureManager, IChunk chunk)
	{
		BlockPos.Mutable blockPos = new BlockPos.Mutable();
		int chunkWorldX = chunk.getPos().getXStart();
		int chunkWorldZ = chunk.getPos().getZStart();
		
		if(chunkWorldX == 0 && chunkWorldZ == 0)
		{
			PlanetoidsHandler.getInstance().generateFirstSolarSystem();
		}
		
		ArrayList<Planetoid> toGenerate = new ArrayList<Planetoid>();
		
		for(Planetoid p : PlanetoidsHandler.getInstance().unloadedPlanetoids)
		{
			if(Math.sqrt(Math.pow(p.getPosition().x - chunkWorldX, 2) + Math.pow(p.getPosition().z - chunkWorldZ, 2)) < p.getRadius() * 4)
				toGenerate.add(p);
		}
		
		for(Planetoid p : PlanetoidsHandler.getInstance().loadedPlanetoids)
		{
			if(Math.sqrt(Math.pow(p.getPosition().x - chunkWorldX, 2) + Math.pow(p.getPosition().z - chunkWorldZ, 2)) < p.getRadius() * 4)
				toGenerate.add(p);
		}
		
		for(Planetoid p : toGenerate)
		{
			for(int i = 0; i < 256; i++)
			{
				if(Math.abs(i - p.getPosition().y) > p.getRadius())
					continue;
				
				for(int j = 0; j < 16; j++)
				{
					for(int k = 0; k < 16; k++)
					{
						Vector3d v = new Vector3d(chunkWorldX + j, i, chunkWorldZ + k);
						
						if(PlanetoidsUtil.getDistance(p.getPosition(), v) < p.getRadius())
							chunk.setBlockState(blockPos.setPos(j, i, k), p.getBlock(v), false);
					}
				}
			}
		}
	}

	public int getHeight(int x, int z, Heightmap.Type heightmapType)
	{
		return 0;
	}

	public IBlockReader func_230348_a_(int p_230348_1_, int p_230348_2_)
	{
		return new Blockreader(new BlockState[0]);
	}
}

Edit: Once again I underestimated my ability to solve this kind of problem. It turns out I just needed to rewrite the codec definition and then register it in my main mod file.

Registry.register(Registry.CHUNK_GENERATOR_CODEC, new ResourceLocation(MOD_ID, "chunk_generator"), PlanetoidsChunkGenerator.CODEC);

Edited January 4, 20214 yr by nanorover59