BiomeCreator biomeCreator = new BiomeCreator ( "firstname", "secondname" ) ;
biomeCreator. setWaterColor ( new java. awt. Color ( 76, 255, 255 ) ) ;
biomeCreator. setGrassColor ( new java. awt. Color ( 136, 0, 0 ) ) ;
biomeCreator. setSkyColor ( new java. awt. Color ( 1, 73, 51 ) ) ;
biomeCreator. setWaterFogColor ( new java. awt. Color ( 255, 255, 255 ) ) ;
//.... more stuff can be added here (Mobs, Structures....)

// If true: allows the Biome to overwrite existing Biome if exist (also possible to overwrite vanilla Biomes with same name: minecraft:plains, minecraft:desert ...)
BiomeCreator. CustomBiome customBiome = biomeCreator. createBiome ( true ) ;
 

// You can use one of the following PlacementType's to influence the y-coordinate of the placement
BiomeDecorationPopulator. PlacementType placementType_heightMap = new BiomeDecorationPopulator. HeightmapPlacementType (HeightMap. MOTION_BLOCKING ) ;
BiomeDecorationPopulator. PlacementType placementType_range = new BiomeDecorationPopulator. RangePlacementType ( 10, 10 ) ;

// Use at least one or more of the PlacementType's like in the following example
biomeCreator. addCustomDecorationPopulator (BiomeDecorationType. TOP_LAYER_MODIFICATION, new BiomeDecorationPopulator ( new BiomeDecorationPopulator. PlacementType [ ] {placementType_heightMap } ) {
    @Override
    public void populateDecoration (WorldModifier worldModifier, int x, int y, int z ) {
        // worldModifier only has a few methods, but you can use them to modify the world
        // one Method allows to get a BlockData at a specific position
        // the other Method allows to set a BlockData at a specific position
        // Note: NEVER! try to set Blocks via Bukket-API at this point, because it will cause a lot of lag
        //       and will probably cause a crash
        // The following example will check the Block at the given position and will set it to a Diamond Block
        // if the Block is AIR
        // x and z are the lowest x and z coordinates of the chunk that is currently being generated
        // y is the y coordinate which is modified by the PlacementTypes
        BlockData blockData = worldModifier. getBlockData (x,y,z ) ;
        if (blockData. getMaterial ( ) == Material. AIR ) {
            worldModifier. setBlockData (x, y, z, Material. DIAMOND_BLOCK. createBlockData ( ) ) ;
        }
    }
} ) ;
 

BiomeProviderLines. Builder builder = new BiomeProviderLines. Builder ( 1, true ) ;
// size: 1, true: repeating in X-Dir

builder. addBiome (myCustomBiome ) ;
builder. addBiome (org. bukkit. block. Biome. PLAINS )

AdvancedBiomeProvider biomeprovider = builder. create ( ) ;

AdvancedWorldCreator#setAdvancedBiomeProvider (biomeprovider ) ;
 

AdvancedWorldCreator creator = new AdvancedWorldCreator ( "advancedworld" ) ;
creator. seed ( 123456789 ) ;

// The following will change the logical functions of Minecraft like Ambient-Light or if a Bed will work or explode and much more.
// By using the NamespacedKey you can either change vanilla Environments or create a new Environment
EnvironmentBuilder environmentBuilder = new EnvironmentBuilder ( new NamespacedKey ( "my_cutom_environment", "the_environment_to_use" ) ) ;
environmentBuilder. setOverwriteSettingsIfExist ( true ) ;
environmentBuilder. setHeight ( 384 + 64 ) ;
environmentBuilder. setMinY ( - 128 ) ;
environmentBuilder. setLogicalHeight ( 384 + 64 ) ;
environmentBuilder. setAmbientLight (0.0f ) ;
environmentBuilder. setBedWorks ( false ) ;
environmentBuilder. setUltraWarm ( true ) ;
environmentBuilder. setRespawnAnchorWorks ( true ) ;
environmentBuilder. setNatural ( false ) ;
creator. setEnvironmentBuilder (environmentBuilder ) ;

// The following will allow you to change the Word-Generation completly
// Note that the minY and Height+LogicalHeight should be identical with this settings and both (the EnvironmentBuilder and GeneratorConfiguration) need to be set to activate the settings!
// By using the NamespacedKey you can either change vanilla  GeneratorSettings or create a new GeneratorSetting
GeneratorConfiguration generatorConfig =
new GeneratorConfiguration ( new NamespacedKey ( "my_cutom_genconfig", "the_genconfig_to_use" ) ) ;
generatorConfig. setDefaultBlock (Material. DIAMOND_BLOCK ) ;
generatorConfig. getNoiseGeneration ( ). setMinY ( - 128 ) ;
generatorConfig. getNoiseGeneration ( ). setHeight ( 256 + 128 ) ;
// The following will copy the NoiseRouterData of an existing Generator like Overworld, or The End ....
generatorConfig. setNoiseRouterData (NoiseRouterData. OVERWORLD ) ;
creator. setGeneratorConfiguration (generatorConfig ) ;

org. bukkit. World advancedworld = creator. createWorld ( ) ;