Sky Archipelago guide for FTB Skies 2: Aero 1.0.3 to 1.8.0

Same as in the FTB Skies 2: Aero 1.10.0 guide

Sky Archipelago is a terrain generation mod that adds a floating-islands world type for Minecraft 1.21.1. The project page says it currently only supports NeoForge for 1.21.1, because it was built towards Create Aeronautics airship gameplay. This pack includes version 1.3.6, and the mod has been in the pack since 1.0.3 or earlier.^[1][2]

It is not limited to sky worlds. The mod can also make ocean worlds with islands spread far apart, so the world you get is mostly down to how you configure it.^[1]

What you can configure

The project page lists these options as of the 1.0.0 release and says more configuration is planned for future updates. The sources here do not show what was added up to 1.3.6, so check your own config for anything newer.^[1][2]

• The project page lists island spawning density and the spacing of cluster islands as options, as of the 1.0.0 release.^[1]
• The project page lists an island sizing mode as of the 1.0.0 release: RANDOM rolls between a min and max for each island, while SPECIFIC lets you set small, medium and large sizes, each with its own min/max and percentage weight.^[1]
• The Y range islands can spawn in, plus low, mid and high bands with weights for where islands appear more or less often.^[1]
• The project page lists, as of the 1.0.0 release, a choice between ocean enabled or void enabled, with water or lava as the ocean block type.^[1]
• Island archetypes (Classic, Bowl/Crater and Terrace) that you can toggle and weight, and a toggle to relax structure spawning rules, since the mod has its own logic for placing structures on islands.^[1]

Presets

A preset is your whole configuration saved so you can share it. The mod has a dedicated preset menu to save, load and delete presets, and you can share them as plain JSON text. There are also OP-only commands to create, overwrite and export a preset.^[1]

The project page, written around the 1.0.0 release, says that for a dedicated server you set level-type to sky_archipelago:sky_islands in server.properties. After the server has run once, you paste your values into sky_archipelago-common.toml in the config folder. It says the Export Dedicated button or the in-game command /skyarchipelago preset export_dedicated can copy your preset for that. The sources here do not confirm whether these steps changed by 1.3.6.^[1][2]

Same as in the FTB Skies 2: Aero 1.10.0 guide

Good news and a heads-up. Sky Archipelago is a world generation mod, not a content mod. It gives you sparse floating-island overworld generation with structure support validation, so your first steps here are about reading the world around you rather than crafting something.^[1][3]

Unverified The sources I was given for this mod include no in-pack recipes for its items and no quests, so there is no verified crafting order to show for it.

What the world looks like in this pack

The pack changed several of the mod's defaults to make the islands rarer and more spread out. Island density is islandDensity = 0.2 (the mod default is 0.4), and lower values mean larger sky gaps. Cluster spacing is clusterSpacing = 300 blocks (the mod default is 96). Expect long trips between islands.^[4]

Spacing mode is clusterSpacingMode = "CONSISTENT", which uses fixed spacing, so the cluster spacing value above is the one that applies. minClusterSpacing and maxClusterSpacing only matter in DYNAMIC mode.^[4]

Island sizes follow the random mode set in islandSizeMode, so each island rolls its radius between the minimum and maximum. In this pack that is minIslandRadius = 24 up to maxIslandRadius = 67 blocks.^[4]

All the island shapes can spawn: classicArchetypeEnabled, bowlCraterArchetypeEnabled, terraceArchetypeEnabled and crescentArchetypeEnabled are all true. Satellite and spire companion islands also generate around anchor islands, since clusterCompanionIslandsEnabled is true.^[4]

Island centers sit between minIslandY = 14 and maxIslandY = 261. The pack raised that top limit from the mod default of 170, so some islands float quite high.^[4]

The optional ocean layer is switched off here (oceanEnabled = false), so nothing fills in below the islands.^[4]

Where to change things

All the values above live in config/sky_archipelago-common.toml.^[4]

Unverified The pack also has a config/sky_archipelago-server.toml, but its contents are not shown in the sources here, so any server-side detail would be set in that file and is unverified.

Operators also get preset commands for creating, overwriting and exporting a world-generation preset, which is handy for sharing a setup. The mod's project page lists them under the /skyarchipelago command.^[1]

Same as in the FTB Skies 2: Aero 1.10.0 guide

Most of what shapes your Sky Archipelago world lives in the common config file. The pack changes a good number of the mod's defaults there, so the world is sparser and a bit smaller-scaled than the mod would give you on its own. Here are the options you are most likely to care about.^[1][4]

Island density and spacing

• islandDensity is 0.2 in this pack (mod default 0.4). It is the chance that a cluster cell becomes an island anchor, and lower values create larger sky gaps.^[4]
• clusterSpacing is 300 blocks (mod default 96), so clusters sit much further apart.^[4]
• clusterSpacingMode is set to CONSISTENT, which uses the fixed spacing above. The pack also changes maxClusterSpacing to 115 (mod default 96), but that value is only used by the DYNAMIC mode, and minClusterSpacing stays at 96.^[4]

Island size

islandSizeMode is RANDOM, so every island rolls a radius between the global minimum and maximum. The pack lowers both: minIslandRadius is 24 (mod default 30) and maxIslandRadius is 67 (mod default 75).^[4]

The small, medium and large settings only apply if the mode is switched to SPECIFIC, but the pack has tuned them anyway:^[4]

• Small islands: radius smallIslandMinRadius 24 (default 30) to smallIslandMaxRadius 41 (default 42), weight smallIslandWeight 0.34 (default 0.28).^[4]
• Medium islands: minimum radius mediumIslandMinRadius 37 (default 43), weight mediumIslandWeight 0.33 (default 0.3). The maximum radius, mediumIslandMaxRadius, stays at 58.^[4]
• Large islands: radius largeIslandMinRadius 34 (default 50) to largeIslandMaxRadius 50 (default 75), weight largeIslandWeight 0.2 (default 0.42).^[4]

Height range

• minIslandY is 14 (mod default 20) and maxIslandY is 261 (mod default 170), so island centers can spread over a much taller band.^[4]
• deepslateStartY is 15 (mod default 16): island interior at or below this Y uses a deepslate substrate.^[4]

Structures on islands

The pack widens the search for spots to put smaller sky structures: smallSkyLocalSearchRadiusBlocks is 14 (default 10), smallSkyLocalSearchStepBlocks is 4 (default 8) and smallSkySearchRadiusChunks is 8 (default 6). Larger sky-surface structures get surfaceSkyLocalSearchRadiusBlocks at 24 (default 16).^[4]

skyStructureWhitelist lists structures that skip the normal support and grounding checks, though they still need a nearby island. In this pack it includes the shellbound_for_airship airships, the sky_whale_ship whale structures, the castle in the sky from mostructures and the Create Structures Arise pillager steampunk airship.^[4]

Things left off

oceanEnabled is false, so there is no ocean layer under the islands, and terrainOverlapMode is VOID. disableIslandsOverOceanBiomes is also false.^[4]

Server file

The server config has one pack change: adaptiveColumnCacheMinTtlSeconds is 180 seconds (mod default 15), which matches the maximum of 180, so the worldgen column cache TTL is effectively pinned there.^[5]

serializeStructurePlacementForParallelWorldgen stays true. It exists for compatibility with parallel worldgen mods such as C2ME, and the file says to disable it only for benchmarking or debugging. The debug and verbose log options are all off.^[5]