Horizonmatica

Horizonmatica is a re-creation of Litematica (with its printer) for Horizon. Load a schematic, see it as ghost blocks in your world, check your build against it, get a material list, and let the printer place the missing blocks.

Features

• Formats: .litematic (versions 1–7, several regions), .schem (Sponge v1–v3: WorldEdit, FAWE, Amulet, Axiom), .schematic (MCEdit / WorldEdit up to 1.12) and vanilla structure .nbt. Older files are upgraded with Horizon's data fixer, the same way old worlds are.
• Overlay: missing blocks as translucent real block models (chests, banners, heads and other block entities included), optionally visible through walls.
• Verifier: wrong block (red), wrong state (orange), extra block (pink), plus a progress HUD.
• Layers: all / one layer / above / below / range.
• Placement: move, rotate, mirror; a move mode for mouse wheel and arrow keys. Each placement is remembered per world and dimension and restored when you join again.
• Material list: missing, total and carried, with item icons, in the HUD, in chat or in the menu.
• Menu (M): a screen of its own, drawn with the game's widgets.
• Printer: places one missing block within reach every few ticks, from the bottom up. It only clicks when Horizon's own placement logic says the click produces exactly the wanted state (stairs, slabs, logs, furnaces…). Redstone-aware order, repeater, comparator and note block setup after placing, double slabs and stacks, chests, falling blocks. The camera never moves.

Usage: put schematics into schematics/ next to options.txt of your instance (/hm folder shows the path), then /hm load <name> or press M. All commands and keys are in the README.

What it does and doesn't do

• Reads only files in the instance's schematics/ folder, and creates that folder if it's missing.
• Writes nothing itself: settings and remembered placements go through Horizon's mod settings.
• Network: no connections of its own. The only thing sent to a server is what the printer does: the same block-placing clicks a player would make (with the matching look direction), and hotbar slot changes.
• "Open folder" in the menu opens the schematics folder in your file manager through Horizon's own function.
• No telemetry, no downloads, no code run from schematic files. Schematics are parsed as data only.

⚠️ On other people's servers, automatic placing may break the rules or trip anti-cheat. The printer is off until you turn it on (K or /hm printer on). Its air place option (on by default) is noticed by anti-cheat plugins such as Grim.

Version: native mods use game internals, so Horizonmatica is pinned to one Horizon commit (currently Nightly 2026-11-01, 4aa6854). A new Nightly needs a new release.

Credits

The idea, the way it's used, the file format and the behaviour come from Litematica by masa (maruohon), maintained by Sakura-Ryoko, and from Litematica Printer by aleksilassila. Horizonmatica is not an official project of these authors, isn't made or endorsed by them, and contains none of their code. Only the file format and the behaviour are re-created. If you like it, go and support the originals.

Menus built with horizon-menus. MIT licensed.