Adding custom structures to village pool.

[h3tR]

Hi,

I have a structure that I want to spawn in villages.

They used to work back in 1.17.xx but Since porting to 1.18.2 that is the only feature that I haven't figured out how to make it work.

I have tried every method I found online including some mixin implementations but they didn't work either.

So now I've been following a tutorial made by TelepathicGrunt on Github which uses accesstransformers(which have been applied succesfully) but unfortunately I haven't gotten it to work.
I've done some troubleshooting and I found out that the structure does in fact get added to the required pool but that is I really got out of it.

Here is my code:

@Mod.EventBusSubscriber(modid = "pepsimc")
public class WorldEvents {

	@SubscribeEvent
	public static void addVillageTemplate(final ServerAboutToStartEvent event){
		//TODO
		Registry<StructureTemplatePool> templatePoolRegistry = event.getServer().registryAccess().registry(Registry.TEMPLATE_POOL_REGISTRY).orElseThrow();
		Registry<StructureProcessorList> processorListRegistry = event.getServer().registryAccess().registry(Registry.PROCESSOR_LIST_REGISTRY).orElseThrow();

		String[] biomes = {"plains","snowy","savanna","desert","taiga"};
		for (String biome : biomes) {
			addBuildingToPool(templatePoolRegistry, processorListRegistry, new ResourceLocation("village/" + biome + "/houses"), "pepsimc:village/" + biome + "/houses/" + biome + "_pepsi_store_1", 5);
		}
	}



	private static void addBuildingToPool(Registry<StructureTemplatePool> templatePoolRegistry,
										  Registry<StructureProcessorList> processorListRegistry,
										  ResourceLocation poolRL,
										  String nbtPieceRL,
										  int weight) {

		// Grabs the processor list we want to use along with our piece.
		// This is a requirement as using the ProcessorLists.EMPTY field will cause the game to throw errors.
		// The reason why is the empty processor list in the world's registry is not the same instance as in that field once the world is started up.
		Holder<StructureProcessorList> emptyProcessorList = processorListRegistry.getHolderOrThrow(ResourceKey.create(
				Registry.PROCESSOR_LIST_REGISTRY, new ResourceLocation("minecraft", "empty")));

		// Grab the pool we want to add to
		StructureTemplatePool pool = templatePoolRegistry.get(poolRL);
		if (pool == null) return;

		// Grabs the nbt piece and creates a SinglePoolElement of it that we can add to a structure's pool.
		// Use .legacy( for villages/outposts and .single( for everything else
		SinglePoolElement piece = SinglePoolElement.legacy(nbtPieceRL, emptyProcessorList).apply(StructureTemplatePool.Projection.RIGID);

		// Use AccessTransformer or Accessor Mixin to make StructureTemplatePool's templates field public for us to see.
		// Weight is handled by how many times the entry appears in this list.
		// We do not need to worry about immutability as this field is created using Lists.newArrayList(); which makes a mutable list.
		for (int i = 0; i < weight; i++) {
			pool.templates.add(piece);
		}


		// Use AccessTransformer or Accessor Mixin to make StructureTemplatePool's rawTemplates field public for us to see.
		// This list of pairs of pieces and weights is not used by vanilla by default but another mod may need it for efficiency.
		// So let's add to this list for completeness. We need to make a copy of the array as it can be an immutable list.
		List<Pair<StructurePoolElement, Integer>> listOfPieceEntries = new ArrayList<>(pool.rawTemplates);
		listOfPieceEntries.add(new Pair<>(piece, weight));
		pool.rawTemplates = listOfPieceEntries;
	}

}

I feel like there is just one thing that I'm overseeing so any help shall be greatly appreciated.

Thank you very much!
 

[warjort]

I don't know why your code isn't working, but doing it that way seems like a bad idea to me?

* You are modifiying the worldgen settings after it is saved to level.dat. Who knows what problems that will cause? It does at least mean DataFixerUpper will have no chance to fix your config when worlds are updated to new versions of minecraft.

* You are completely ignoring the datapack mechanism. Which means if a user wants to totally redefine how villages spawn using a datapack, your code is still going to run and modify their data

 

Here's a different way of doing it used by immersive engineering. It modifies the BuiltinRegistries during bootstrap which means it doesn't have the above 2 problems.

https://github.com/BluSunrize/ImmersiveEngineering/blob/1.18.2/src/main/java/blusunrize/immersiveengineering/common/world/Villages.java

It still looks pretty hacky to me. 🙂