Gameplay Extras

Gameplay Extras

The gameplay extras are a data pack that Arnis puts into the world: cars and trains that move, traffic lights that switch, an advancement tab for the places in your area and even a zombie outbreak.

All extras are off by default. Turn them on under Settings > Gameplay, or with the flags below on the command line.

• They only work in Java Edition, since they're built on data packs and display entities.
• They need Minecraft 1.21.4 or newer, the pause menu and the zombie outbreak need 1.21.6.
• They aren't available in One World mode yet, since every new area would overwrite the data pack of the one before.

Moving Vehicles

--moving-vehicles

Cars drive the streets and trains run the tracks.

Cars drive at the speed limit (from maxspeed, otherwise a default per road type), queue behind each other and turn at junctions. With Working Traffic Lights on too, they stop at red. They only use roads cars are allowed on, so no footways, private roads, bus lanes or tunnels. Each car is made of block displays, in a few body types and colours. To keep the game running smoothly, there are at most 1500 cars in a world and only the cars near a player move.

Trains run on the mapped tracks: trams, metros, S-Bahns and regional and intercity trains, each with its own top speed. Lines without stations also get freight trains. They stop at their stations, leave the area at the edge and come back after a short break. The whole timetable is worked out when the world is generated, and the data pack just follows it in game.

Working Traffic Lights

--traffic-lights

Signal heads at every mapped traffic signal (highway=traffic_signals or crossing=traffic_signals) that actually switch between red, amber and green, one head per approach, with pedestrian and bike lights at crossings and mast arms over wider roads. Cross directions take turns. In Germany, Austria, Switzerland, the UK and Ireland, red and amber show together before green, like in real life.

Without this setting traffic signals are still built, just as static poles.

Discoveries

--discoveries

An advancement tab for the named places in your area: landmarks, museums, viewpoints and peaks, parks, places of worship, stations, bridges, sports grounds and civic buildings. Walk to a place and it unlocks. Places need a name in OSM, and notable ones (with a Wikidata or Wikipedia link, heritage status or tourism=attraction) are picked first. A world has up to 72 discoveries.

Arnis Pause Menu

--pause-menu

Adds an "Arnis" button to the pause menu with a few pages:

• Travel: teleport to the spawn or to the most interesting places in the area
• Discoveries: which places you've found so far
• Outbreak: the state of the zombie outbreak, if it's on
• Credits: where the data in the world comes from

This needs Minecraft 1.21.6. On older versions you get the credits in the chat instead.

Zombie Outbreak

--zombie-outbreak

Survive five nights in your own city. Every night a bigger wave of zombies comes through the streets, on the last night there's a boss, and every morning a supply drop lands somewhere nearby. The world starts in survival mode. Needs Minecraft 1.21.6.

Moon & Mars Gravity

--body-gravity

For Moon and Mars worlds only: players and mobs get the real lower gravity, and fall damage is scaled to match, so you can fall much further before it hurts.

How it works

Everything is in one data pack, arnis_extras, in the world's datapacks folder. Arnis works out the heavy parts while generating (the lane network, the train timetables, which places count as discoveries, where the signal heads are) and writes them into the pack as storage. The pack itself only has to follow them in game.

The pack targets 1.21.4. Newer versions renamed or added some things, so the pack has overlays for 1.21.5, 1.21.6, 26.1, 26.2 and 26.3 that Minecraft picks automatically.

The code is in src/datapack/ (the pack, dialogs and discoveries), src/element_processing/cars.rs, trains.rs, train_bodies.rs and traffic_lights.rs. The pack's functions are in assets/minecraft/datapack_extras/.