Iris - Dimension Engine

Create a world of your own with Iris

Explore a world pack, customize it for your server, or build a dimension from scratch. Iris gives you control over terrain, biomes, caves, structures, wildlife, and loot through editable, shareable packs.

The Iris client mod is optional for multiplayer. Generation runs on the server. The client adds a map, inspection overlay, pregeneration HUD, and Studio notifications.

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Explore Iris worlds

Overworld and Underworld

• Overworld landscapes include redwood forests, alpine peaks, dunes, oases, swamps, rainforests, volcanic islands, and fungal terrain.
• Underground biomes include lantern grottos, sculk cathedrals, frost vaults, sulfur chambers, and mineral formations.
• Underworld reimagines the same geography with different materials, lighting, fluids, and ecology.
• Matching Overworld and Underworld seeds share landforms and coordinates.
• Underworld uses an open, full-height landscape without a Nether roof.

World packs are separate downloads. Installing Iris does not replace your existing world.

Terrain, rivers, and caves

• Mountains, valleys, plateaus, coasts, and flatter building areas.
• Overhangs, undercuts, ledges, fissures, and decorated rock shelves.
• Floating islands with their own vegetation, objects, and wildlife.
• Rivers with tributaries, rapids, waterfalls, and coastal inlets.
• Underground waterways, grottos, and deep-fluid bodies.
• Cave profiles with custom shapes, depths, fluids, and floor, wall, and ceiling materials.
• Faults, cenotes, lava tubes, travertine basins, and connected chambers.

Content varies by pack.

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Design your own generation

Terrain and geography

• Arrange continents, oceans, coastlines, regions, and biomes.
• Set terrain height, sea level, biome scale, and transitions.
• Combine noise, mathematical expressions, and image inputs.
• Shape 3D terrain, floating islands, ceilings, and stacked layers.
• Control river sources, routes, and outlets.

Trees, reefs, formations, and ruins

Generate trees, fungi, coral, crystals, rocks, and ruins with configurable materials, shapes, density, and placement.

• Trees with custom trunks, branches, forks, roots, and canopies.
• Arches, hoodoos, sea stacks, boulders, basalt columns, icebergs, and spires.
• Procedural variations alongside saved builds.

Buildings and structures

• Save and place builds with rotation, terrain alignment, height, and biome rules.
• Assemble multi-piece Iris jigsaw structures.
• Generate villages, forts, towers, and underground complexes.
• Include native Minecraft, datapack, and mod structures.

Saved Iris jigsaws generate on every supported platform. Jigsaw Studio authoring is plugin-only.

Biomes, wildlife, and loot

• Custom soil, rock, surface palettes, vegetation, deposits, ores, and underwater decoration.
• Sky, fog, water, grass, and foliage colors.
• Temperature, precipitation, and ambient particles.
• Vanilla or modded creatures with equipment, names, attributes, passengers, and death loot.
• Spawning rules for location, time, weather, and nearby populations.
• Loot by biome, region, dimension, or structure.
• Custom block drops and marker-based encounters.
• Regional sounds, particles, potion effects, and commands.

Image maps

Use PNGs for heightmaps, biomes, regions, surface materials, and masks. Scale, move, rotate, mirror, or blend them with procedural generation.

Paint island outlines, plan server geography, or reserve areas for specific biomes.

Image Map Studio requires a desktop environment. Headless servers use the same resources through JSON.

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Authoring and server tools

Studio and pack editing

Create temporary Studio worlds and preview pack changes in new terrain.

• Hot reload for supported pack changes.
• VS Code workspaces, JSON schemas, and content-aware autocomplete.
• Object selection, saving, pasting, rotation, and undo.
• Pack validation, compatibility checks, and packaging.
• Generated-content search and inspection.
• Reusable snippets.

Some dimension changes require reopening Studio or restarting. Edits affect new generation.

Worlds and pregeneration

• Create multiple dimensions and teleport between them.
• Pregenerate terrain with progress, pause, resume, and stop controls.
• Stage pack updates for new chunks with transition bands.
• Preserve existing terrain and generation history.
• Inspect generation metrics and compatibility reports.
• Extend generation through APIs for content, terrain, pregeneration, and stored world data.

Large terrain changes can still leave visible seams.

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What the optional client mod adds

• Vision map: Press M for a full-screen map with pan and zoom.
• What overlay: Press J for biome, region, cave-biome, and height information.
• Pregeneration HUD: Press H for progress, speed, ETA, and pause status.
• Studio notifications: Pack reload feedback with refreshed map and inspection data.

World packs stay on the server.

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Getting started

For a dedicated server:

1. Install the matching Iris loader jar in mods/ and start the server.
2. Run /iris download pack=overworld and wait.
3. Restart to load the pack's registry data.
4. Run /iris create myworld overworld 1337.
5. Enter with /iris tp irisworldgen:myworld.

Download Underworld with /iris download pack=underworld.

In singleplayer, install Iris locally and prepare your packs. They appear as Iris World Types during world creation.

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Compatibility & Notes

• This listing is for the Iris mod: Minecraft 26.3 only, on Fabric, Forge, and NeoForge. Requires Java 25.
• The original Spigot server plugin is available separately.
• Client tools require matching Iris and Minecraft versions.
• Iris-generated worlds work without the client mod. Other mods used by a pack may require client installation.
• Packs can use installed mods' blocks, items, and entities.
• Native structures are enabled by default. Native placed features, including modded ores and trees, need pack configuration.
• Iris controls terrain generation. Other generators' terrain, carvers, and surface rules do not automatically combine with it.
• WorldEdit imports, schematic conversion, and some authoring tools are plugin-only.
• This is VolmitSoftware's world-generation engine. Iris Shaders is a separate project.