Caves Not Cliffs [Backported]

Caves Not Cliffs 2.0.0 backports Java 1.18.2 Overworld terrain and its represented Caves & Cliffs content to Minecraft 1.12.2. New Overworlds use a default-on, finite CaveBiomesAPI-backed schema from Y=-64 through Y=319, while existing worlds keep their saved generator contract.

Key features

Native Java 1.18.2 Overworld generation

• Default, Large Biomes, and Amplified profiles backed by the ported positional RNG, noise, spline, climate, density-cave, aquifer, carver, and surface-rule stacks
• Complete deterministic 16×384×16 columns with bedrock, the Y=0..8 deepslate transition, ore veins, fluid scheduling, and a bounded weighted cache
• A virtual 3D biome resolver with a legacy surface-biome projection for Minecraft 1.12 spawning, colors, and chunk storage
• The six available Minecraft 1.12 structure families retained through a structure-only bridge
• /cncbiome for querying the resolved biome at any position

Caves, mountains, and native features

• Lush and dripstone cave biomes with Java 1.18.2 feature ordering
• Meadow, Grove, Snowy Slopes, Jagged Peaks, Frozen Peaks, and Stony Peaks
• Exact ordinary ore bands and exposure reduction, large copper and iron veins, soft disks, underwater magma, tuff placement, and amethyst geodes
• Functional terrain-generated powder snow, buckets, dispensers, layered cauldrons, sinking, freezing, and leather protection

Faithful block and crafting families

• The complete deepslate family, all eight deepslate ores, raw copper/iron/gold and their blocks, smelting, crafting, and stonecutting
• Later-vanilla tuff shape variants and the retained custom calcite decorative set
• Every copper oxidation and waxed stage across blocks, cut blocks, stairs, and slabs, with radius-four aging, axe scraping/unwaxing, lightning cleaning, and lightning rods
• Budding amethyst and all four growth stages, canonical shard drops and sounds, tinted glass, and a functional spyglass
• Functional stonecutter and composter systems

Living caves and dripstone mechanics

• Glow berries as the edible cave-vine planting item, with no invented seed item
• Azaleas and flowering azaleas, both leaf types, rooted dirt, hanging roots, moss spreading, small and big dripleaf, spore blossoms, potting, composting, and azalea-tree growth
• One canonical pointed-dripstone family with growth, thickness recalculation, falling stalactites, stalagmite damage, trident breaking, water retention, and faithful water/lava cauldron behavior

Axolotls, bees, and honey

• Five axolotl variants, breeding and blue mutation odds, bucket/NBT round trips, aging, dehydration, play-dead behavior, combat support, and lush-cave spawning
• Bee pollination, breeding, anger, stinging, hive routing, crop growth, sounds, animation, and persistent NBT
• Generated and sapling-grown bee nests, three-occupant nests and hives, honey production, smoke-safe harvesting, Silk Touch occupant preservation, comparators, and dispensers
• Honeycomb waxing through interaction, crafting, and dispensers, plus honey-block movement and piston adhesion including honey/slime incompatibility
• Normal and soul campfires with four-slot cooking, smoke and signal-smoke columns, projectile lighting, water dousing, hive calming, container handling, drops, sounds, and particles
• All sixteen dyed candles plus the undyed candle, one-to-four candle stacking, waterlogging, lighting and extinguishing, and the complete hidden candle-cake state family

World and save compatibility

• world.enableForNewOverworlds=true applies only when an Overworld is first created
• Terrain schema, base world type, generator options, and terrain profile are persisted so later config changes cannot convert an existing world
• Released placeholder IDs and state-split blocks are remapped or migrated to canonical content while preserving inventories and block/entity NBT

Creating a v2 world

Install the requirements below and create a world normally. Caves Not Cliffs applies its v2 format to newly created Overworlds by default while preserving the selected base world type and its options. Default, Large Biomes, and Amplified receive native Java 1.18.2 terrain profiles; other compatible 2D types retain their selected generator through the finite delegated bridge. No level-type change is required on a dedicated server.

The setting is written to config/cavesnotcliffs.cfg as world.enableForNewOverworlds=true. Set it to false before creating a world to leave that new Overworld unchanged. The setting is evaluated only at first creation: existing vanilla worlds, schema-1 Caves Not Cliffs worlds, and schema-2 worlds always keep their recorded format. A stale level-type=cavesnotcliffs on a newly created server is treated like the normal default selection and still obeys this config.

Use /cncbiome in-game to identify the cave-biome region at your current position, or /cncbiome <x> <y> <z> to inspect another coordinate.

Performance

Java 1.18.2-style terrain is inherently heavier than vanilla 1.12.2 generation. 2.0.0 fills each terrain column's density cells and virtual biome quarts on a small worker pool, controlled by -Dcavesnotcliffs.terrainThreads=N (default: half the available processors, capped at 16; 1 restores the fully serial path), and pre-starts the likely next column while the server thread populates the current one. Column output is bit-identical either way. First-time spawn preparation still takes a minute or two on older CPUs, and lowering the view distance helps during both spawn preparation and exploration.

Known limitations

• Native Java 1.18.2 terrain is supplied for Default, Large Biomes, and Amplified. Flat, Customized, Default 1.1, debug, and compatible third-party 2D types retain their selected generator and options through the finite delegated bridge. Existing third-party cubic types remain authoritative and are not wrapped.
• Schema-2 worlds retain only Minecraft 1.12's mineshaft, village, stronghold, temple, ocean-monument, and woodland-mansion structure families. Post-1.12 structures are not backported.
• Goats, foxes, and glow squids are not backported. Tropical fish are represented only by the narrow clownfish-based bucket bridge used by axolotl breeding.
• Same-seed fidelity covers native terrain density, climate, caves, aquifers, surfaces, and the ported feature pipelines. Whole-chunk parity is not claimed around retained 1.12 structures or omitted modern ecosystems.
• Existing schema-1 draft-v2 saves intentionally retain their original vanilla surface, deep worm caves, and upper headroom to prevent chunk seams.
• Nether and End generation remain unchanged.
• CaveBiomesAPI owns the process-wide finite chunk height. Client and server must use the same API build; the server synchronizes its authoritative range when a player joins.

Requirements

Caves Not Cliffs requires:

• CaveBiomesAPI
• MixinBootstrap