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Iris replaces the chunk generator. Terrain, biomes, caves, structures, objects, entities and loot all come out of a project pack: a folder of readable JSON you can edit, version and share like any other source.
- Terrain and regions Compose land, sea, shore and cave biomes through region definitions, each with its own shape, height and surface behavior.
- Biome settings Palettes, colors, decorators, spawns, weather, and the generator links that set the height band a biome occupies.
- Cave carving Cave shapes, profiles and dimension carving, with cave biomes that carry their own palettes and decorators.
- Objects Place object files with rotation, scale, markers, loot and find-and-replace rules, across 20 placement modes.
- Structures Build and edit jigsaw structures in game, or import vanilla and datapack structures into your pack as editable resources.
- Noise and expressions Drive a generator with a noise style, an image map or an arithmetic expression, and choose how its values are interpolated.
- Decorators and deposits Surface, ceiling, shoreline and fluid detail, and ore deposits remapped to other blocks inside a height band.
- Procedural objects Trees, ruins, formations, coral, fungi and crystals generated from pack JSON, each as a seeded pool of deterministic variants.
- Entities and loot Entity spawning, equipment, attributes, passengers, and the loot tables that replace their vanilla drops.
- Pregeneration Generate your world with on-disk cache to resume later with live progress updates.