[1.13.2] Biome specific spawning

[crackedEgg]

I'm trying to spawn mobs in specific biomes. I noticed addSpawn method is protected in Biome class and there doesn't seem to be a forge registry for this. Is there another way to do this in 1.13.x or am I missing something? 

[LTNightshade]

I would try something like : 

Biome biome = RegistryManager.ACTIVE.getRegistry(Biome.class).getValue(new ResourceLocation("minecraft", "badlands"));
biome.getSpawns(EnumCreatureType.MONSTER).clear();
biome.getSpawns(EnumCreatureType.MONSTER).add(new Biome.SpawnListEntry(EntityType.BAT,1,1,2));

 

[crackedEgg]

Using both your suggestions I got spawning working. It looks like I needed an EntitySpawnPlacement as well. I didn't see any spawns until I added the placement. Thanks for all your help!

private void registerEntitySpawn(EntityType<? extends EntityLiving> type, Biome[] biomes, int spawnProb, int minSpawn, int maxSpawn) {
    EntitySpawnPlacementRegistry.register(type, EntitySpawnPlacementRegistry.SpawnPlacementType.ON_GROUND,
            Heightmap.Type.MOTION_BLOCKING_NO_LEAVES, null);

    for (Biome bgb : biomes) {
        Biome biome = ForgeRegistries.BIOMES.getValue(bgb.getRegistryName());
        if (biome != null) {
            biome.getSpawns(EnumCreatureType.MONSTER).clear();
            biome.getSpawns(EnumCreatureType.MONSTER).add(new Biome.SpawnListEntry(type, spawnProb, minSpawn, maxSpawn));
        }
    }
}