Terrain Recast

A Fabric mod that rebuilds overworld terrain from a plate-tectonics driven causal pipeline. 用「板块构造 → 大地貌 → 气候 → 高度」的因果链重写主世界地形。 Chinese: README.md

What it does

Terrain Recast takes over overworld terrain generation with custom density functions. Terrain is no longer "Perlin noise stacked into a height" but:

plates (soft Worley Voronoi)
  → continentalness / plate-boundary proximity
  → orogenic belts & mountain walls / trenches / plateaus / basins / rifts
  → erosion envelope (sharp young ranges vs. rounded old ones)
  → analytic height field → density function → real block terrain

All heights come from a single continuous field: plate identity is never read directly (so straight Voronoi edges never turn into hundred-block vertical cliffs). Peaks reach Y≈1500 (1200–1700 measured across seeds under the default config), and the full vanilla world height (2544 blocks) is supported.

Features

• Plate-driven terrain — soft Voronoi plates + F2−F1 boundary distance field: mountains along boundaries, trenches on the ocean side
• Two range archetypes — sharp ranges (edge⁶ × ridge³, alpine aretes) and broad massifs (low-frequency blocks, plateau-like bodies)
• Snowline model — two-staged altitude cooling: gentle below the local snowline, steep above it; the snowline floats with latitude and aridity (≈980 ± 480 blocks), so arid high mountains stay bare rock (stony_peaks) and only humid ones get snow caps
• Flat-topped massifs — large-scale noise carves out mesa zones; peaks above relative height 900 inside them are cut to a near-level tabletop at 82% of their height (5% residual slope), giving mesas/tepuis with sheer shoulders; outside the zones summits stay sharp
• Himalayan belts — convergent boundaries are stitched into one continuous wall by low-frequency ridge lines, not a row of isolated cones
• Six landform classes — plains / hills / plateaus (with escarpments) / basins (flat floors) / rifts / mountain walls, distributed by plate setting and latitude
• Spawn protection — terrain within 900 blocks of spawn is flattened into plains, so you never spawn on a mountain
• Real surface — custom material_rule places surface blocks by altitude, temperature and slope
• Commands & presets — locate peaks, inspect the terrain underfoot, export/import tuning presets
• Open API — data modifiers, feature injection, ore registry, event bus (see the API guide)

Requirements

Installation

1. Install a matching Fabric Loader
2. Drop Fabric API and this mod's jar into mods/
3. Create a new world (the terrain generator is fixed at world creation; existing worlds are unaffected)

Commands

peak samples the analytic height field directly and generates no chunks; a 20000-block radius takes roughly 12 ms:

Top 5 peaks within 10000 blocks:
1. (9654, 4352) height 1528 · surface Y≈1591 · distance 10482
...

Heights are relative to sea level; surface Y ≈ height + 63.

Configuration

Config lives in config/terrain_recast.json (per-world; applied when the world is reloaded).

Development

Build

$env:JAVA_HOME = "C:\Program Files\Java\jdk-25"
.\gradlew build --no-configuration-cache

Artifacts land in build/libs/. Add --rerun-tasks to force a fresh jar.

Verification

A green build is not "it works": registry and feature conflicts only show up in runServer.

When tuning terrain parameters you must pin the world seed (level-seed in run/server.properties); otherwise every run picks a new seed and coverage numbers swing by ±50%.

Layout

src/main/java/yifei/terrain/recast/
├── worldgen/cell/     analytic field core (RealCellLookup, Worley, Cell)
├── worldgen/densityfunction/  custom density functions
├── worldgen/feature/  vegetation, ore deposits
├── commands/          command implementations
├── config/            config and presets
├── core/              registration and bootstrap
├── api/               public API (modifiers, events, injection, ores)
└── mixin/             required injections

src/main/resources/data/
├── minecraft/         overrides: dimension / noise_settings / density_function / material_rule
└── terrain_recast/    custom density functions, tags, recipes

api-guide/             add-on API documentation (public contract)

Documentation

• Add-on API guide — full API usage, runnable examples, pitfall list
• docs/ holds internal project documents (design vision, handover notes); kept in the development workspace only and not shipped with the repository

License

Released under the Apache License 2.0. Third-party reference projects are credited in NOTICE.

Minecraft is a trademark of Mojang Studios. This project is not affiliated with Mojang or Microsoft.