SimCity Expansion

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Contents

• Overview
• Features
• Requirements and installation
• Opening the manager
• The manager
• Structure editor
• Capturing builds from the world
• Build packs
• Structure formats
• Directory layout
• Commands
• Documentation
• Building from source
• License
• Acknowledgements

Overview

SimCity Expansion is a NeoForge mod for Minecraft 1.21.1 that adds a complete building expansion-pack pipeline to New-Simukraft-1.21.1 (a city-building mod). It lets you import structures from three common formats, convert them into SimuKraft's buildable format, organise and edit them through a Litematica-style manager, and package them as portable zip packs for one-click install and sharing.

Integration with SimuKraft is a pure file-system convention — the mod writes .sk and .nbt files under <game dir>/simukraftbuilding/<category>/ — so there is no compile-time dependency on SimuKraft. The manager is built on Minecraft's own GUI toolkit and needs no extra library, and the command interface runs on a dedicated server as well.

Features

• Three structure formats — vanilla .nbt, Litematica .litematic (multi-region

auto-merge), and Sponge/WorldEdit .schem (v1/v2/v3), all converted to SimuKraft's vanilla buildable format on install.

• Robust conversion — older structures are upgraded through the game DataFixer,

missing mod blocks are detected against the registry, and block-entity contents (chest inventories, signs, and so on) are preserved (entities are not).

• Litematica-style manager (open with \) — file tree, fixed-width info panel,

material list, and layered previews: embedded thumbnail, real-block 3D scene, isometric voxel view, and top-down map.

• Full structure editor — place / break / pick / replace, brush painting, box

selection with fill / frame / hollow / expand, copy / cut / paste, rotate and mirror, symmetry axis, undo / redo, slice planes, and preset camera views; export to .litematic or save and install directly.

• Capture from the world — mark two corners in-game, capture the selection as a

blueprint, and optionally include block-entity contents.

• Zip pack ecosystem — manifest-tracked install / uninstall, one-click export of

installed buildings into a shareable pack, an optional pack icon and an index.json file manifest, and pass-through of SimuKraft native job/trade definitions (format v2).

• No hard dependencies — the manager runs on Minecraft's own GUI toolkit and SimuKraft

is integrated purely through the file system, so neither is a compile-time dependency.

• Server-friendly — the /buildpack command (operator level 2, with tab-completion)

installs loose files and packs and captures regions on dedicated servers, reusing the same conversion pipeline as the GUI.

• Localised — English, Simplified Chinese, and Traditional Chinese; numbers, dates,

and file sizes are formatted per the active game language.

Requirements and installation

| Requirement | Version | | --- | --- | | Minecraft | 1.21.1 | | NeoForge | 21.1.233 or newer |

Place the jar in your mods/ folder — there are no other mod dependencies. The in-game manager works out of the box on a client; on a dedicated server the jar loads headless and exposes the /buildpack command.

Opening the manager

Press <kbd>\\</kbd> (backslash) in-game. All bindings are rebindable under the mod's category in Options -> Controls.

| Action | Default key | | --- | --- | | Open the build pack manager | <kbd>\\</kbd> | | Set world selection corner A | <kbd>[</kbd> | | Set world selection corner B | <kbd>]</kbd> | | Capture the selection as a blueprint | <kbd>'</kbd> | | Toggle "include block-entity contents" | unbound | | Clear the world selection | unbound |

The manager

The left panel has three tabs: