Nether Expanse Incendium

NetherExpanse by CevAPI

NetherExpanse removes the Nether roof, keeps normal terrain below Y 256, and raises the Nether dimension height so optional sky content can exist above the normal terrain ceiling. Most screenshots are of the Incendium compatible version.

Packaging note:

• NetherExpanse is now distributed as four separate standalone datapacks.
• This split exists to satisfy Modrinth’s packaging requirements and to make installation clearer.
• Each variant is self-contained. Do not stack multiple NetherExpanse variants together.
• Pick exactly one NetherExpanse datapack for a world.

Available standalone variants:

NetherExpanse

Vanilla-compatible standalone datapack with all NetherExpanse structures enabled.

This One

Standalone datapack with all NetherExpanse structures enabled and built-in Incendium compatibility.

Nether Expanse (No Structures) _[Link Updated When Approved]_

Vanilla-compatible standalone datapack with NetherExpanse terrain changes enabled but all NetherExpanse structures disabled.

NetherExpanse Incendium (No Structures) _[Link Updated When Approved]_

Standalone datapack with NetherExpanse terrain changes, all NetherExpanse structures disabled, and built-in Incendium compatibility.

Which one should I use?

• Not using Incendium: choose one of the non-compat variants.
• Using Incendium: choose one of the IncendiumCompat variants.
• Want sky structures, Nether cities, and Nether ancient cities: choose an AllStructures variant.
• Want only the terrain/dimension changes without NetherExpanse structures: choose a NoStructures variant.

Shared settings:

• Terrain top: tapers out by Y 256
• Dimension height: 416
• The terrain cap can be adjusted in data/minecraft/worldgen/noise_settings/nether.json before creating a world.
• Keep noise.height and the dimension height above the terrain cap so terrain tapers into open sky instead of flattening.
• The noise override includes preliminary_surface_level so newer 1.21.x and 26.1.x loaders accept the registry entry.

Structures included in the AllStructures variants:

• nether_expanse:sky_spawn_portal Rare bedrock sky portal hypercube at Y 280. Purple portal particles appear in the center; entering that center effect teleports you to a safe Nether location within 1000 blocks of 0,0, below Y 128.

• nether_expanse:nether_city Very rare Nether city generated from the bundled templates, surface-anchored with red and black shulkers and high-end Nether loot.

• nether_expanse:sky_nether_ship Extremely rare flying ship at about Y 322, generated from the bundled template, with super-rare premium loot.

• nether_expanse:nether_ancient_city Nether ancient city generated at low Y with custom hostile spawns and high-end Nether loot.

Structure rarity in the AllStructures variants:

• Spawn portals: spacing=160, separation=64
• Nether cities: spacing=224, separation=96
• Nether ancient cities: spacing=224, separation=96
• Nether ships: spacing=384, separation=160

Nether ancient city rarity vs other structures:

• Candidate density is roughly proportional to spacing^2 before biome checks.
• Nether ancient city (spacing=224) is about 50176 / 25600 ~= 2.0x rarer than spawn portals (spacing=160).
• Nether ancient city (spacing=224) is the same rarity as Nether cities (spacing=224).
• Nether ancient city (spacing=224) is less rare than Nether ships (spacing=384).
• Nether ancient city (spacing=224) is about 50176 / 729 ~= 69x rarer than vanilla bastion candidates (spacing=27).

Rarity reference vs vanilla bastions:

• Vanilla bastion remnants use spacing=27, about 1 candidate per 27x27 = 729 chunks before biome checks.
• NetherExpanse spawn portals (spacing=160) are about 25600 / 729 ~= 35x rarer than bastion candidates.
• NetherExpanse Nether cities (spacing=224) are about 50176 / 729 ~= 69x rarer than bastion candidates.
• NetherExpanse Nether ancient cities (spacing=224) are about 50176 / 729 ~= 69x rarer than bastion candidates.
• NetherExpanse Nether ships (spacing=384) are about 147456 / 729 ~= 202x rarer than bastion candidates.

Useful commands for the AllStructures variants:

/execute in minecraft:the_nether run locate structure nether_expanse:sky_spawn_portal
/execute in minecraft:the_nether run locate structure nether_expanse:nether_city
/execute in minecraft:the_nether run locate structure nether_expanse:sky_nether_ship
/execute in minecraft:the_nether run locate structure nether_expanse:nether_ancient_city

Known issues:

• This does not behave well with ViaFabric due to lighting changes in 26.1.x, so if a server on 1.21.11 has this datapack and a 26.1.2 client joins it, shadows will be pitch black. Users must connect to the server using the same-version client as the server.