[1.16.3] Generate structure in custom biome

[Beethoven92]

I am experiencing troubles trying to add a custom structure into a custom biome. The problem is that my biome is registering before my structure and so of course i get a "Registry object not present" error on startup:

Quote

Exception message: java.lang.NullPointerException: Registry Object not present: betterendforge:mountain_structure

I saw this post a while ago but this seems to not be applicable concerning structure registration: https://forums.minecraftforge.net/topic/93134-solved-1163-registering-biome-with-modded-features/ at least not in a way i can figure out. It seems that there is not an overload of BiomeGenerationSettings.Builder#withStructure that accepts a Supplier. I should mention that both the biome and the structure works perfectly on their own. My biome is correctly added and generated in the End and i can generate my structure in vanilla biomes using the BiomeLoadingEvent, so the problem shows up only when trying to register the structure in my custom biome. Code for reference:

 

BiomeTemplate is just workaround wrapper to help constructing the biome, and BetterEndBiome stores a Biome object internally

public class CrystalMountainsBiome extends BetterEndBiome
{
	public CrystalMountainsBiome() 
	{
		super(new BiomeTemplate("crystal_mountains").setGrassColor(255, 133, 211).
				                  setFoliageColor(255, 133, 211).
				                  setMobSpawn(EntityClassification.MONSTER, EntityType.ENDERMAN, 50, 1, 2).
				                  addStructure(ModConfiguredStructures.MOUNTAIN_STRUCTURE)); // This will crash on startup
	}
}

Biome registry:

public class ModBiomes 
{
	public static final DeferredRegister<Biome> BIOMES = 
			DeferredRegister.create(ForgeRegistries.BIOMES, BetterEnd.MOD_ID);

	public static final RegistryObject<Biome> CRYSTAL_MOUNTAINS = BIOMES.register("crystal_mountains",
			() -> new CrystalMountainsBiome().getBiome());
}

Structure registry:

public class ModStructures 
{
    public static final Map<Structure<?>, StructureSeparationSettings> BETTEREND_STRUCTURES = new HashMap<>();
	
	public static final DeferredRegister<Structure<?>> STRUCTURES = 
			DeferredRegister.create(ForgeRegistries.STRUCTURE_FEATURES, BetterEnd.MOD_ID);
	
	public static final RegistryObject<Structure<NoFeatureConfig>> MOUNTAIN = registerStructure("mountain_structure", 
			new MountainStructure(NoFeatureConfig.field_236558_a_));
    
    private static <T extends Structure<?>> RegistryObject<T> registerStructure(String name, T structure) 
    {
        return STRUCTURES.register(name, () -> structure);
    }
    
    public static void setupStructures()
    {
    	setupStructure(MOUNTAIN.get(), 
    			new StructureSeparationSettings(5, 2, 1234567890));
    }
    
    private static <F extends Structure<?>> void setupStructure(F structure, 
    		StructureSeparationSettings structureSeparationSettings)
    {
       	//NAME_STRUCTURE_BIMAP
    	Structure.field_236365_a_.put(structure.getRegistryName().toString(), structure);

    	DimensionStructuresSettings.field_236191_b_ = // Default structures
                ImmutableMap.<Structure<?>, StructureSeparationSettings>builder()
                        .putAll(DimensionStructuresSettings.field_236191_b_)
                        .put(structure, structureSeparationSettings)
                        .build();
    	
    	BETTEREND_STRUCTURES.put(structure, structureSeparationSettings);
      }
 }

Configured structures:

public class ModConfiguredStructures 
{
    public static final StructureFeature<NoFeatureConfig, ? extends Structure<NoFeatureConfig>> MOUNTAIN_STRUCTURE = 
    		ModStructures.MOUNTAIN.get().func_236391_a_(IFeatureConfig.NO_FEATURE_CONFIG);

    private static <FC extends IFeatureConfig, F extends Structure<FC>> StructureFeature<FC, F> register(String name, StructureFeature<FC, F> structureFeature)
    {
        return WorldGenRegistries.register(WorldGenRegistries.CONFIGURED_STRUCTURE_FEATURE, name, structureFeature);
    }
    
    public static void registerStructureFeatures()
    {
    	WorldGenRegistries.register(WorldGenRegistries.CONFIGURED_STRUCTURE_FEATURE, 
    			new ResourceLocation(BetterEnd.MOD_ID, "mountain_structure"), MOUNTAIN_STRUCTURE);
    }
}

Relevant main class code:

    public BetterEnd() 
    {
    	IEventBus modEventBus = FMLJavaModLoadingContext.get().getModEventBus();

        modEventBus.addListener(this::setupCommon);
    	
        ModStructures.STRUCTURES.register(modEventBus);
    	ModBiomes.BIOMES.register(modEventBus);
    }

    private void setupCommon(final FMLCommonSetupEvent event)
    {
    	event.enqueueWork(() -> {
            ModStructures.setupStructures();
            ModConfiguredStructures.registerStructureFeatures();
        });     
    }

 

Does anyone know which way to go about this?

Edited November 8, 2020 by Beethoven92

[vemerion]

58 minutes ago, Beethoven92 said:

Does anyone know which way to go about this?

I am not super familiar with the world generation part of Minecraft, so forgive me if I am way off, but could you not just wait and add the structure to the biome until after your structure is registered (i.e. last in setupCommon)?

[Beethoven92]

Does that imply i need to grab the structures list from the BiomeGenerationSettings and manually adding my own structure to the list?

[vemerion]

19 minutes ago, Beethoven92 said:

Does that imply i need to grab the structures list from the BiomeGenerationSettings and manually adding my own structure to the list?

Yes, use the getStructures() method, and add your custom structure.

[Beethoven92]

I tried with this line at the end of the enqueueWork:

ModBiomes.CRYSTAL_MOUNTAINS.get().getGenerationSettings().structures.add(() -> ModConfiguredStructures.MOUNTAIN_STRUCTURE);

No crash but the structure is nowhere to be found inside the biome, and using the /locate command shows that in fact it is not generating anywhere

Edited November 8, 2020 by Beethoven92

[vemerion]

On 11/8/2020 at 9:15 PM, Beethoven92 said:

No crash but the structure is nowhere to be found inside the biome, and using the /locate command shows that in fact it is not generating anywhere

Alright, let's try another way: If you extend the BiomeGenerationSettings.Builder class, and add your own method that takes a structure supplier, i.e. something like this:

public static class Builder extends BiomeGenerationSettings.Builder {
  public BiomeGenerationSettings.Builder withStructureSupplier(Supplier<StructureFeature<?, ?>> structure) {
    this.structures.add(structure);
    return this;
  }
}

and then use this builder to create your biome instead. Does that work?

[Beethoven92]

Oh sorry Vemerion, i actually solved that issue yesterday and forgot to say that in the post..i have not tried what you suggest so i don't know if it works but it seems it actually could. Anyway i solved it by giving away the structure deferred register and by using static initializers for the Structure and the StructureFeature. Those are then registered inside the RegistryEvent.Register<Structure<?>. This way the code above works because now the structure is known at the time the biome is initalized. I was kinda hoping to do the job without giving away the deferred register though..so i may also try your idea. World generation stuff really seems to be a dirty job to handle right now..

[vemerion]

9 hours ago, Beethoven92 said:

Oh sorry Vemerion, i actually solved that issue yesterday and forgot to say that in the post..i have not tried what you suggest so i don't know if it works but it seems it actually could. Anyway i solved it by giving away the structure deferred register and by using static initializers for the Structure and the StructureFeature. Those are then registered inside the RegistryEvent.Register<Structure<?>. This way the code above works because now the structure is known at the time the biome is initalized. I was kinda hoping to do the job without giving away the deferred register though..so i may also try your idea. World generation stuff really seems to be a dirty job to handle right now..

Ah, I am glad you were able to solve it! I agree with you, world generation is such a hassle right now, I am hesitant to even go near those systems. But it will get better down the line I guess. Also, just because I am curious, are you working on a port of the fabric BetterEnd mod, or are you creating your mod from scratch? Either way, interesting mod idea!

[Beethoven92]

3 hours ago, vemerion said:

Also, just because I am curious, are you working on a port of the fabric BetterEnd mod, or are you creating your mod from scratch? Either way, interesting mod idea!

Yep, i am porting the BetterEnd fabric mod to Forge, because i find their asthetics crazy good (not really minecrafty though) and i think this mod deserves to be played by forge users also. Luckily they are working under the MIT license!

[vemerion]

1 hour ago, Beethoven92 said:

Yep, i am porting the BetterEnd fabric mod to Forge, because i find their asthetics crazy good (not really minecrafty though) and i think this mod deserves to be played by forge users also. Luckily they are working under the MIT license!

Alright, cool! Be sure to give me a ping when you release the mod