WallMaster

I host a modded Minecraft server for a small group of friends running All the Mods 10, and we decided to build a city, with skyscrapers, streets, and a skyline. If you've ever tried building a glass high-rise one block at a time, you know the problem: it's a grind.

I looked at the existing builder mods, couldn't find one that felt right for survival...most either required creative mode, gave you too much power, or skipped the preview step entirely. So I built WallMaster.

Placing the outer shell of a 30-story glass skyscraper in survival mode means hundreds of individual block placements, each requiring you to stand in exactly the right spot. It also means constantly checking your inventory count, backtracking to fix misaligned rows, and accidentally placing blocks in the wrong plane.

The game has no built-in way to preview what a wall will look like before you commit your materials to it. Every other tool that solves this either bypasses survival constraints or requires a mod loader's admin editor. Neither of which fit what we were doing.

The core interaction is deliberately minimal. Hold the material in your offhand, right-click a block face to set the first corner, aim around to size the ghost, right-click again to lock the far corner, then right-click air to build. The ghost follows your crosshair the whole time, with per-cell colour coding that tells you exactly what will be placed, what's blocked, what you can't afford, and what's already correct.

The preview is purely client-side — no packets are sent while you're aiming. When you confirm, the full plan is rebuilt server-side, all cells are re-validated, and materials are counted and spent atomically. A failed build costs nothing; you can't be short-changed by a race condition.

The mod is a standard NeoForge mod written in Java 21, split so the dedicated server never loads anything under client/. The Builder's Wand state (selection corners, build mode, template palette, slab half) is stored on the ItemStack as a data component, so it survives logout, inventory moves, and being dropped and picked up.

Material safety uses a closed-world approach: only plain full cubes, standard slabs, approved glass blocks, and approved standard carpets are accepted. Everything else fails closed — unknown modded blocks are rejected rather than allowed through. Pack authors can extend the allowed set through four public additive datapack tags (wallmaster:non_full_cube_materials, wallmaster:block_entity_materials, wallmaster:carpet_materials, wallmaster:delete_protected).

The server config is synced to clients on join so the ghost preview respects the same limits the server will enforce. A mismatched client simply cannot use the wand.