Generation Settings

Generation Settings

Open the settings with the gear button next to Start Generation. Arnis remembers your settings between sessions. Every setting can be reset to its default on its own, and there's also a button to reset all of them at once.

The settings are grouped the same way as in the app. The last column shows the matching command line flag, in case you use the command line instead of the GUI.

World

How the world plays when you first join it.

Setting	What it does	CLI
Game Mode	Survival, Creative (default) or Spectator.	--gamemode
World Time	Time of day the world starts at. Default is noon.	--world-time (in ticks: 0 = dawn, 6000 = noon, 18000 = midnight)
World Type	What lies past the edge of your area: Void (default, the area is an island in the void) or Flat (a superflat grass plain at the area's ground level). Java only.	--world-type void|flat
World Map Item	You start with a map. On Java it's a locked map item that shows the whole area, on Bedrock the game's own starting map. On by default.	--map-item false turns it off
Custom World Name	Lets you name the next Java world yourself with the pencil next to the Start button, instead of the default "Arnis World N".	GUI only (see --world-name for One World)
One World	Every area you generate is added to one persistent Java world at its real position. Explained on the One World page.	--one-world

Generation

What gets built from the map data.

Setting	What it does	CLI
Generation Mode	Objects + Terrain (default): buildings, roads and nature on real elevation. Objects only: the same on flat ground. Terrain only: real elevation with water and nature, but no buildings or roads. Blueprint: roads, rails, water and nature, with every building drawn as a light blue outline on the ground so you can build it yourself. In both of these, towns and fields turn back into the natural cover around them.	--mode geo-terrain|geo-only|terrain-only|blueprint
Additional Buildings	Adds building footprints from Overture Maps where OpenStreetMap has none, and fills in heights for OSM buildings that don't have any. Helps a lot in areas that are badly mapped, but can occasionally add a false positive from satellite detection. On by default.	--overture false turns it off
3D Models & Props	Famous landmarks as real 3D models, plus bundled props like cars on parking lots, boats, cranes, excavators and planes. Fountains, lighthouses and wind turbines are props too, so they're gone when this is off. On by default.	--no-3d turns it off
Interior Generation	Rooms, furniture and loot chests inside buildings, furnished by what the building is used for (flats, shops, schools, offices, churches and so on). Off by default because it's slower.	--interior
Signage	Readable signs, drawn as images on maps in invisible item frames. Basic (default) covers public signage: street names, traffic signs, transit stops, information boards and billboards. Full adds shop name plates, house numbers and crossing signs. None turns it off. Java only.	--signage none|basic|full
Winter	Snow on the ground, roofs and trees, rivers and lakes frozen from their shores, and every biome snowy.	--winter
Post-Apocalyptic	Buildings partly collapsed and broken open, cracked roads with grass growing through, rubble in the streets with the odd fire still burning, moss and vines on the walls and every light out.	--post-apocalyptic

Winter and Post-Apocalyptic work with every mode and can be combined.

Terrain & Nature

Setting	What it does	CLI
Terrain Height	Multiplies the height of the terrain. 2.0 makes hills twice as tall, 0.5 half as tall. Buildings and trees keep their size. The GUI goes from 0.25 to 4, the CLI from 0.1 to 10.	--height-multiplier
Fill Ground	Fills everything below the surface with stone and ore veins, so the world is usable for survival mining. Without it, only a few blocks below the surface are filled and it's empty below that.	--fillground
Caves	Carves Minecraft-style caves into the filled ground: noise caves, tunnels and ravines, flooded pools, underground rivers, a lava sea at the bottom, ores and eight cave biomes (lush, dripstone, deep dark, mushroom, ice, amethyst, volcanic and coral). Turns on Fill Ground automatically. At the default ground level, caves only show up under terrain that rises above the lowest point of the area, since they need rock to carve into.	--caves (see also --cave-biomes)
Real Tree Cover	Places trees from a global canopy height map, so trees stand where real ones do at roughly their real height. Without it, every tree covered area from the land cover data is treated as forest. On by default.	--canopy-height false turns it off
Legacy Trees	Uses the old, simple procedural trees instead of the bundled tree models.	--legacy-trees
Max Tree Size	Largest tree model to place: Small (up to 6 blocks), Medium (12), Big (20), Tall (28) or Giant (default, no limit). Taller picks are swapped for a smaller species from the same region where there is one.	--max-tree-size small|medium|big|tall|giant

Building Facades

Dresses building walls with textures from photographs. There's a separate page about this: Building Facades.

Setting	What it does	CLI
Facade Source	Off (default): walls use the colours and materials from the map data. Preset: a bundled photo picked by building type, no download needed, Java only. Mapillary: real street photos of each building where there are any.	--building-facades for Preset, a Mapillary token for Mapillary
Mapillary Token	Your free token from mapillary.com/developer. It stays on your computer.	--mapillary-token or the MAPILLARY_TOKEN environment variable
Facade Mode	Photos (default): hangs the photos themselves on the walls, Java 1.21.4+ only. Blocks: matches wall blocks to the photos and places windows and doors from them, works on every format.	--mapillary-facade-mode photos|blocks
Facade Detail	Standard fits any graphics card that runs Minecraft. High is sharper but needs a modern one on whatever machine opens the world.	--facade-detail standard|high
Precompute Area	Builds the facades for the selected area before you generate, so the generation itself is quicker.	GUI only

Gameplay

Extras that run from a data pack inside the world. All of them are off unless you turn them on, they are Java only and not available in One World mode yet. More about them on the Gameplay Extras page.

Setting	What it does	Minecraft	CLI
Arnis Pause Menu	An "Arnis" button in the pause menu with travel, discoveries and the data credits.	1.21.6+	--pause-menu
Discoveries	An advancement tab for the area's landmarks, museums, parks, stations and more. Each one unlocks when you walk there.	1.21.4+	--discoveries
Working Traffic Lights	Traffic lights that actually switch between red, amber and green, with pedestrian lights at crossings.	1.21.4+	--traffic-lights
Moving Vehicles	Cars that drive the streets at the speed limit, queue and turn at junctions, and trains, S-Bahns, metros and trams that run the mapped tracks and stop at their stations. Cars stop at red if traffic lights are on too.	1.21.4+	--moving-vehicles
Zombie Outbreak	Five nights of growing zombie waves through your streets, a boss on the last night and a supply drop every morning. Starts the world in survival.	1.21.6+	--zombie-outbreak
Moon & Mars Gravity	Lower gravity for players and mobs on Moon and Mars worlds, with fall damage scaled to match.	1.21.4+	--body-gravity

Map & Input

Setting	What it does	CLI
Bounding Box	Type exact coordinates instead of drawing on the map, as min_lat,min_lng,max_lat,max_lng (spaces work too).	--bbox
World Scale	Blocks per metre. 1.00 is real-world size, smaller worlds generate faster. The GUI goes from 0.05 to 2.5, the CLI up to 4.0. Below 0.30 buildings and roads are too small to render, so only terrain and land cover are generated.	--scale
Rotation Angle	Turns the area clockwise by up to 90 degrees either way, so streets can line up with the block grid. You can also draw a line along a street with the rotation tool on the map. Not available in One World mode.	--rotation
Map Theme	Style of the map you pick your area on: Standard, Satellite, Topographic, Smooth Bright, Smooth Dark, Modern or Custom.	GUI only
Custom Map Source	Your own tile server as a URL with {z}, {x} and {y}.	GUI only

Application

Setting	What it does	CLI
Language	Language of the interface.	GUI only
Java Save Path	Folder new Java worlds are created in. Arnis finds your .minecraft/saves folder on its own and falls back to the Desktop if there is none.	--output-dir
Bedrock Save Path	Folder the .mcworld file is saved to. Desktop by default.	--output-dir with --bedrock
Luanti Save Path	Folder new Luanti worlds are created in. Only shown when Luanti is turned on under Advanced.	--output-dir with --luanti
Anonymous Crash Reports	Sends anonymous crash and error reports to help me fix bugs. Arnis asks you about this on the first start, and it stays off unless you agree.	GUI only
Clear Cache	Deletes everything Arnis has cached: OSM data, elevation, land cover, canopy height, Overture buildings, 3D models and facade photos. Old elevation tiles and Mapillary photos are also cleaned up on their own after 30 days.	GUI only

Advanced

Options for mods, compatibility and experiments. Most worlds never need them.

Setting	What it does	CLI
Extend build height	Raises the build height with a bundled pack (a data pack on Java, a behaviour pack on Bedrock) so mountains fit at 1:1. Java 1.21.4+ gets Y -2032 to 2031, Bedrock 1.21.40+ goes up to Y 511. Both are experimental: Minecraft asks about "Experimental Features" on the first load, and the world can't be uploaded to Realms.	--disable-height-limit
Legacy terrain	Uses the older, coarser AWS Terrain Tiles elevation (about 30 m) instead of Mapterhorn. Meant as a fallback when the default elevation download fails or gets stuck.	--aws-only-elevation
Bake lighting	Precomputes the light in every chunk, so distant chunks render lit in LOD mods like Voxy or Chunky without you visiting them first. Slower.	--bake-lighting
Pre-generate Voxy LOD	Writes the Voxy LOD cache together with the world, so distant terrain renders on your first join instead of needing /voxy import current. Turns on Bake lighting. Java only.	--voxy-lod
Luanti	Adds Luanti (Mineclonia) as an output format next to Java and Bedrock. Experimental.	--luanti

Settings that are only on the command line

A few options aren't in the GUI on purpose, e.g. the ground level (--ground-level) and the flood fill timeout (--timeout). They're listed on the Command Line Usage page.