GlymeraFloatingIslands - Sky Islands for Hytale

Create new worlds made entirely of floating islands - Minecraft-style. Choose a theme or let each zone keep its native biome.

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What is GlymeraFloatingIslands?

GlymeraFloatingIslands adds floating sky islands worlds to your server. Each world consists purely of islands suspended in the air - no ground, no ocean, no caves. The islands are generated natively by Hytale's terrain pipeline, so they come with grass, flowers, trees, structures, NPCs and mobs out of the box, exactly as they would on a normal map.

You pick a biome preset when you create a world, and every island in that world is built from the preset's blocks. Or you go with the native preset and let each zone keep its own biome - so a single world has sand islands in desert zones, snow islands in tundras, grass islands in plains, and so on.

Works out of the box - one command to create, one to teleport. No client mod needed.

Quick Start

/fi biomes             - Show available biome presets
/fi create sky native  - Create a new floating-islands world named "sky"
/fi tp sky             - Teleport to it
/fi back               - Return to your previous world

That's it. The world is generated, saved, and persists across server restarts.

Biome Presets

Preset	Surface	Atmosphere
`native`	per-zone	Mixed - sand in deserts, snow in tundras, grass in plains, etc.
`grasslands`	Soil_Grass / Soil_Dirt / Rock_Stone	Classic green Minecraft-style
`desert`	Soil_Sand_White / Rock_Sandstone / Rock_Stone	Warm sandy islands
`snow`	Soil_Snow / Rock_Ice / Rock_Stone	Frozen arctic islands
`volcanic`	Rock_Basalt / Rock_Volcanic / Rock_Slate	Dark basalt floating rocks
`crystal`	Rock_Quartzite / Rock_Marble / Rock_Calcite	Pale crystalline islands

Every preset places native covers (grass, flowers, trees), structures (Hytale Unique-Prefabs) and NPC spawns on the islands. Only block materials and island density differ per preset.

Commands

Command	Who	Description
`/fi create <name> <biome>`	OP	Create a new floating-islands world
`/fi tp <name>`	OP	Teleport to a managed world
`/fi back`	OP	Return to the previous world
`/fi list`	Everyone	List all floating-islands worlds
`/fi biomes`	Everyone	Show all available biome presets
`/fi delete <name>`	OP	Delete a world (folder + config, no server restart needed)
`/fi reload`	OP	Reload the config and re-apply per-world settings

/fi delete cleanly unloads the world from Hytale, deletes its disk folder, and removes it from the plugin config - all in one step. No server restart, no manual cleanup. The player running the command must teleport out first, and no other players may be in the world.

Installation

Place GlymeraFloatingIslands-3.0.0.jar in your server's mods/ folder
Start (or restart) the server
Done! No asset pack, no config file needed for defaults.

Features

Native Hytale world generation - islands use the real biome pipeline, so vegetation, trees, structures, and mobs all spawn naturally
3D Simplex noise islands - organic cave-like shapes, not blocky
Vertical taper - soft edges top and bottom, no flat cutoffs
Guaranteed spawn platform at world origin so you never fall into the void on first teleport
Configurable per world - island size, density, Y-range, custom block choices - tunable in plugins/GlymeraFloatingIslands/config.json and applied with /fi reload
Legacy config support - old noiseScale field from pre-1.0 versions is accepted as an alias for islandSize
Event-driven biome application - islands work correctly even for worlds that already existed before the plugin was installed, and across server restarts
No caves - cave-prefab stalactites that would dangle in empty sky space are disabled per world
No water - empty sky worlds don't generate oceans between islands
Bounded prefab placement - native structure-prefabs only spawn within the island Y-range, never floating in the empty air below
Chunk post-processor - any block that slipped in outside the island range (forced unique-prefab fallbacks, leftover structure bits) is cleared automatically during chunk load

Configuration

Every world gets an entry in plugins/GlymeraFloatingIslands/config.json. Defaults come from the preset you chose. You can override any value and reload:

{
  "worlds": {
    "sky": {
      "islandSize": 0.015,
      "density": 0.30,
      "heightMin": 120,
      "heightMax": 200,
      "surfaceDepth": 3,
      "surfaceBlock": "Soil_Grass",
      "subBlock": "Soil_Dirt",
      "coreBlock": "Rock_Stone"
    }
  }
}

islandSize - noise scale. Smaller = bigger islands. Range: 0.005-0.05.
density - fraction of the Y-range that becomes solid. 0.1 = sparse, 0.3 = minecraft-like, 0.5 = dense, 0.8 = almost solid. Range: 0.05-0.90.
heightMin / heightMax - lowest / highest Y coordinate for islands.
surfaceDepth - thickness of the surface-block layer (grass, sand, snow, etc.).
surfaceBlock / subBlock / coreBlock - the three layers of each island.
native - set to true to inherit the zone's native biome instead of the custom blocks (overrides the three block fields).

After editing, run /fi reload - the scanner re-applies the settings without a server restart.

Performance

Designed to stay lightweight:

Column-level fast-path - 3 pre-sampled noise values per column skip the full 3D-noise loop when the column is obviously empty air
No per-block extras - Hytale's native pipeline does the actual block placement, layering, covers and prefab spawning
No ticking overhead - zero work per tick; all computation happens during chunk generation and chunk load
No threads - two event listeners, one optional 500 ms safety scanner, nothing more
No asset pack - the JAR is around 30 KB

Chunk generation is a little more expensive than vanilla (one custom 3D-noise call per non-empty block in the island Y-range plus a brief post-processing pass), but the column fast-path and Hytale's built-in chunk caching keep regular play smooth.

Good to Know

The plugin only modifies terrain for worlds it manages. Your existing default world and any other worlds are untouched.
NPCs may spawn over open sky and fall off islands - this is intentional; Hytale's spawning system is zone-wide, not Y-bounded.
native mode is marked stable but some Hytale zones render islands as empty - individual zone compatibility may vary. If you see empty patches, use one of the five fixed biome presets.
The chunk post-processor clears every block outside the island Y-range on chunk load. This keeps the sky clean but means player-built structures placed below heightMin or above heightMax do not persist across chunk unload/reload cycles. Build on the islands themselves to preserve your work.
Plugin runs silently - no log output in normal operation.

Made with care by Glymera for the Hytale community