Terralith

The Terralith mod adds roughly 95 overworld, cave and sky biomes to Minecraft 1.21.1 NeoForge, along with a set of structures and a reworked overworld terrain shape. It is built from vanilla blocks, so it adds no new items, blocks or mobs of its own. In Fear Nightfall it covers about 31% of the land surface, making it one of the largest sources of biomes in the pack, and its structures are mixed into several vanilla structure sets.

Overview

Terralith replaces the flat, repetitive look of many vanilla biomes with a wide range of landforms. Mountains come in sharp, stony, painted and volcanic forms, deserts include canyons, spires and oases, and forests range from cherry groves to siberian taigas. Each biome has its own features, grass and foliage colours, and climate settings, so the same vanilla blocks produce very different terrain from one region to the next.

The mod depends on Lithostitched, which injects its features and structures into the game's worldgen data. Terralith shares the overworld with Biomes O' Plenty and Regions Unexplored, and in Fear Nightfall a custom biome source gives each mod a fixed share of the land (see the section below).

Content

Terralith's content falls into four groups: surface biomes, cave biomes, structures and terrain.

Surface biomes are the largest group. Mountain and highland biomes include Alpine Highlands, Highlands, Rocky Mountains, Painted Mountains, Scarlet Mountains, Emerald Peaks, Haze Mountain, Forested Highlands, Temperate Highlands, Arid Highlands, Windswept Spires and Stony Spires. Desert and badlands biomes include Desert Canyon, Desert Spires, Gravel Desert, Oases, Ancient Sands, Savanna Badlands, Snowy Badlands, White Mesa and Warped Mesa. Forest and taiga biomes include Birch Taiga, Siberian Taiga and Grove, Lavender Forest and Valley, Moonlight Grove and Valley, Sakura Grove and Valley, Snowy Cherry Grove, Wintry Forest and Lowlands and Alpine Grove. Jungle and swamp biomes include Amethyst Rainforest, Rocky Jungle, Jungle Mountains, Tropical Jungle, Orchid Swamp and Ice Marsh. Savanna and shrubland biomes include Brushland, Savanna Slopes, Ashen Savanna, Fractured Savanna, Steppe and Shield. Cold and volcanic biomes include Glacial Chasm, Frozen Cliffs, Granite Cliffs, Basalt Cliffs, White Cliffs, Volcanic Crater and Peaks, Caldera, Yellowstone, Yosemite Cliffs and Lowlands and Bryce Canyon. Island and sky biomes include Alpha Islands, Mirage Isles, Deep Warm Ocean, Cloud Forest and Skylands.

Cave biomes generate underground. They include Deep Caves, Frostfire Caves, Fungal Caves, Infested Caves, Mantle Caves, Stone Caves, Thermal Caves and Underground Jungle.

Structures are placed by Terralith's structure sets:

• Desert Outpost, an outpost placed in desert biomes.
• Glacial Hut and Igloo, cold-climate huts.
• Valley Lodge, a lodge placed in valley terrain.
• Mage Towers, tall towers with a seasonal variant for each season and a larger complex layout. Their interiors hold evokers, pillagers, strays, vindicators and witches.
• Rubble, ruins with a separate template set for each biome family (forest, taiga, jungle, mesa, mountain and desert).
• Terralith Spire, a tall tower with a placement set that is sparser than the other surface sets.
• Terralith Underground Structures, underground dungeons, cabins, a refinery, a mining outpost, a bee hive and a sunken tower.

Terralith also adds fortified villages in plains and desert forms. Their placement uses an exclusion zone around vanilla Villages, so they rarely sit beside them in the base game.

Mechanics

Terralith's biomes are standard worldgen biomes. Each has climate values and a set of tags such as mountain, cold, desert, jungle or island, and the game places it wherever its climate matches. Other mods in the pack use the same tags to decide where their own structures and features may spawn.

Structure placement follows the structure set rules. The surface sets for witch huts, desert outposts, valley lodges, glacial huts and igloos, and for rubble, place their structures fairly often. The Terralith Spire set is the sparsest of the surface sets. The Mage Towers set uses its own spacing, and its mobs come from a pool of five types that is placed inside the tower templates rather than from biome spawn lists.

Terrain shape is controlled by custom density functions that build hills, cliffs, arches, dunes and spikes. The effect is strongest in the mountain, desert and badlands biomes.

Changes to vanilla

Terralith changes the vanilla overworld in several ways that a player will notice:

• It reshapes the overworld terrain through its density functions, so hills, cliffs and dunes look different across the world, not only inside its own biomes.
• Its biomes are added to the overworld, so areas that were plains, forest or desert in vanilla can now be Terralith biomes with new surface blocks and features.
• Its structures sit beside vanilla structures. Vanilla villages and witch huts still generate, and Terralith's own types appear next to them.

The jar also includes optional datapacks that switch off the terrain slabs and the custom structures. They are not part of the default setup.

In Fear Nightfall

The pack uses a custom biome source (fnfbiomes:table) that gives each climate cell to every biome allowed there by its original mod, then shares the cell between them by weight. In live sampling over a 32 by 32 km area, Terralith covers 31% of the land against a target of 32%. For comparison, Regions Unexplored covers 28% and Biomes O' Plenty covers 25%, with vanilla at 15%. Biomes of the same type sit next to each other, so forests border forests and mountains border mountains.

Terralith was merged with Geophilic, which also rewrites vanilla biome files. Both mods edit the same files, so the two were combined per biome, with Terralith's features inserted next to their neighbours. A naive merge caused a feature order cycle crash in Biolith, and the merged version avoids it. Terralith loads through Lithostitched's injector together with the rest of the pack.

The pack's structure changes include Terralith in several shared sets:

• Villages: Terralith's fortified villages share the village set with vanilla, Luki's Grand Capitals, ChoiceTheorem's Overhauled Village, Towns and Towers, Dungeons and Taverns, and Villages & Pillages. Each type is weighted equally, and the game picks one per spot.
• Witch huts: Terralith's witch hut is one of six types, alongside the vanilla witch hut, Luki's, YUNG's, Hexerei and the Dungeons and Taverns mangrove hut.
• Towns and Towers tags: that mod shipped its village, outpost and desert-pyramid biome tags with replace set to true, which removed Terralith's biomes from them. The pack rebuilt these tags as a union so that Terralith's biomes are included again.

Individual biome pages list which pack structures generate in each biome, including the horror-themed structures from other mods.