Lost Sky Islands

Overview

The "Lost Sky Islands" datapack (also available as a mod) adds clusters of sky islands to your Minecraft world. These sky islands are generated as Minecraft structures and can vary in size. You can find ruins of some lost civilization on these islands, some of which may hold valuable treasures. If you ever feel bored living on the ground, you can also use the islands to start a sky base.

This datapack is balanced against vanilla progression. The block palettes are also chosen to better fit vanilla worlds (e.g., wool blocks are only used in building parts where they make sense, not in general terrain texturing). Therefore, adding this datapack shouldn't break the vanilla experience.

This datapack is also designed to allow easy customization, so you can tweak it to fit your play style, or to better integrate it in a modpack.

Installation

Datapack File (.zip) Installation

• For single-player worlds, simply add the datapack during world creation and enable it just like installing other datapacks.
• For servers, put the datapack in the datapack folder within your world folder.

Mod File (.jar) Installation

You can easily install it like other mods by putting the .jar file under your Minecraft instance's mods folder. Supported mod loaders include Forge, NeoForge, and Fabric.

IMPORTANT: For Fabric, you also need to install Fabric API.

Compatibility

Minecraft Compatibility

This datapack supports Minecraft versions from 1.21.1 to 26.3.

Mod Compatibility

Since this datapack only adds new structures in the sky, it should be compatible with common worldgen mods. Although the sky islands may look a bit small if you use mods like Tectonic, because they are designed around vanilla scale.

If you use another mod/datapack that also adds structures in the sky, there is a small chance of overlapping structures.

Permission

Feel free to include this mod/datapack in your modpacks.

Although the license is ARR, you're permitted to customize the behaviors of this datapack without directly modifying the original .jar or .zip file by creating another datapack or use tweaker mods. See the "Customization" section below for more details.

Customization

To customize the behaviors of this datapack, you can create a new datapack to override JSON definitions in this datapack (you need to make sure it loads after this datapack/mod), or use more advanced tools like KubeJS.

When not explicitly stated, all JSON or structure NBT file paths below are relative to the data folder in the datapack.

IMPORTANT: Overlays are used to support multiple Minecraft versions. Depending on the Minecraft version you are using, you may need to use files from the corresponding overlay for reference. For example, if you want to override lostskyislands/worldgen/placed_feature/cave_ore_rare_1.json, for Minecraft 1.21.10, you can simply refer to the file under the root data directory as the baseline. However, for Minecraft 26.1, you will need to refer to the same named file under the overlay directory patch_26_1 as the baseline.

Structure Placement

To change the biomes in which sky islands can generate, override the following biome tag: lostskyislands/tags/worldgen/biome/has_structure/sky_islands_plain.json.

To change the spacing or separation of the sky island structures, override lostskyislands/worldgen/structure_set/sky_islands.json. By default, sky islands have a slightly larger separation than villages, so they don't clutter the sky view.

To customize each individual sky island structure's properties (e.g., height range, spawn overrides, etc.), override the structure definitions files under lostskyislands/worldgen/structure.

Loot Tables

All loot tables for chests, barrels, decorated pots can be found under lostskyislands/loot_table/chests, allowing detailed controls of loot generation.

For common chests, barrels, decorated pots on any island:

• lostskyislands/loot_table/chests/barrel_supplies.json
• lostskyislands/loot_table/chests/common_pot_standard.json

For chests, barrels, decorated pots on specific islands:

• lostskyislands/loot_table/chests/barrel_garden.json - On some flower garden islands.
• lostskyislands/loot_table/chests/barrel_ladder.json - On vertical connector islands with ladders.
• lostskyislands/loot_table/chests/barrel_mill.json - On islands with windmill ruins.
• lostskyislands/loot_table/chests/common_pot_animal_pen.json - On islands with animal pens.
• lostskyislands/loot_table/chests/common_pot_cave_supplies.json - On islands with caves.
• lostskyislands/loot_table/chests/common_pot_treasure.json - On islands with fancy shrines.
• lostskyislands/loot_table/chests/sky_doc_chest.json - On islands with sky docks.

For chests, barrels, decorated pots hanging below islands:

• lostskyislands/loot_table/chests/hanging_chest.json
• lostskyislands/loot_table/chests/hanging_pot.json

For chests, barrels, decorated pots in island caves:

• lostskyislands/loot_table/chests/barrel_mushrooms.json - Inside caves with mushroom gardens only.
• lostskyislands/loot_table/chests/barrel_cave_supplies.json
• lostskyislands/loot_table/chests/cave_side_room_chest.json
• lostskyislands/loot_table/chests/cave_side_room_pot.json

For underwater chests, barrels, decorated pots (usually in ponds, pools):

• lostskyislands/loot_table/chests/underwater_chest_standard.json
• lostskyislands/loot_table/chests/underwater_chest_treasure.json
• lostskyislands/loot_table/chests/underwater_pot_standard.json
• lostskyislands/loot_table/chests/underwater_pot_treasure.json

For chests, barrels, decorated pots in building parts:

• lostskyislands/loot_table/chests/apothecary_products.json
• lostskyislands/loot_table/chests/apothecary_supplies.json
• lostskyislands/loot_table/chests/blacksmith_products.json - Finished products like tools, armor pieces, etc., in blacksmith ruins.
• lostskyislands/loot_table/chests/blacksmith_supplies.json - Supplies or raw materials like coal, raw ores, etc., in blacksmith ruins.
• lostskyislands/loot_table/chests/house_barrel_common.json
• lostskyislands/loot_table/chests/house_chest_common.json
• lostskyislands/loot_table/chests/library_treasure.json
• lostskyislands/loot_table/chests/market_stall_common.json
• lostskyislands/loot_table/chests/masons_house_supplies.json
• lostskyislands/loot_table/chests/tavern_food.json
• lostskyislands/loot_table/chests/tavern_supplies.json
• lostskyislands/loot_table/chests/tavern_treasure.json
• lostskyislands/loot_table/chests/temple_treasure.json

For chests, barrels, decorated pots in aircraft parts:

• lostskyislands/loot_table/chests/airship_cargo.json - Contains more treasure items compared to "airship_supplies".
• lostskyislands/loot_table/chests/airship_navigation.json
• lostskyislands/loot_table/chests/airship_supplies.json

For suspicious gravel in house ruins: lostskyislands/loot_table/archaeology/house_ruin.json.

The explorer maps to other sky islands are defined in the special loot table lostskyislands/loot_table/chests/lost_sky_islands_map.json.

Monster Spawners

By default, no standard monster spawners will generate. The corresponding template pool is configured to contain an empty part. If you wish to have monster spawners generated on the sky islands, you will need to override lostskyislands/worldgen/template_pool/spawner/standard_spawner.json to include part with desired monster spawners. These parts must be 1x2x1, with the jigsaw block at the bottom and the spawner block on top. See the example parts under lostskyislands/structure/common/spawner. You can create new parts with new spawner types based on these examples.

If configured correctly, these monster spawners will generate in some building ruins and caves.

Armor Stand Entities

Some building parts will generate armor stand entities with armor pieces on them. If you want to customize the armor pieces there, you need to override this template pool: lostskyislands/worldgen/template_pool/entity/armor_stand_metal_armor.json. The armor stand entity structure parts must be 1x3x1, with the jigsaw block at the bottom and the armor stand entity sitting on top of it. You can refer to examples under lostskyislands/structure/common/entity.

Artifacts

Artifact Generation

Some islands will generate a structure part with an artifact holder, which is an item display entity designed to hold an artifact item (together with an interaction entity to enable player interaction). Fancy particles will appear around the artifact until it is taken by a player. An example structure part is lostskyislands/structure/common/treasure/artifact_pedestal_sword_1.nbt, where an enchanted diamond sword is inserted inside a stone pedestal. To add customized artifacts (e.g., some fancy sword from a mod), you will need to create similar parts of size between 3x3x3 and 3x7x3, and override the following template pool to include your parts: lostskyislands/worldgen/template_pool/treasure/artifact_pedestal.json.

This datapack includes some custom commands to make it easier to create such structure parts. An example procedure to create a new artifact pedestal part:

1. Load lostskyislands/structure/common/treasure/artifact_pedestal_sword_1.nbt in your dev world using a structure block.
2. Run /function lostskyislands:dev/enable_dev_mode (note that dev mode is persistent per world unless you disable it with /function lostskyislands:dev/disable_dev_mode).
3. Hold the artifact item in your main hand, stand at the center of the block you want to place the artifact, and run /function lostskyislands:dev/create_artifact_display. Note that for swords, pickaxes, shields, and tridents there are several specialized functions. For example, lostskyislands:dev/create_artifact_display_sword_in_stone will transform the sword's position as if it is inserted into the block you are standing on. If your item has different translations/rotations than vanilla ones, you may need to adjust the item display entity's transformation properties by yourself.
4. Export the part under a new name.
5. Include the new part in the template pool.

Ore Generation

This datapack uses custom features or processor lists to generate ores in certain islands.

Some islands with small caves generate ores using feature pool elements. To customize the ore generation, you can to override these files to customize possible ores to generate and their frequency: lostskyislands/worldgen/configured_feature/cave_ore_*.json.

You may also override the weights for common, uncommon, rare ores in lostskyislands/worldgen/template_pool/feature/cave_ores.json.

Some islands with large caves generate ores using processor lists. To customize their generation, you need to override lostskyislands/worldgen/processor_list/cave_ores_*.json.

Some island caves will also have rooms with ore piles, which are created by processor lists. To customize these ore piles, you need to override lostskyislands/worldgen/processor_list/ore_pile_*.json.

Bees

Certain islands will generate beehives with bees in them. If you want to include modded beehives or bees, you can override the following template pool: lostskyislands/worldgen/template_pool/decor_beehive_stand.json. The beehive parts used in this pool should have a size of 1x2x1. You can use lostskyislands/structure/common/decor/beehive_stand_full_with_bees.nbt as an example.