HoloBuilder

HoloBuilder is a client-side schematic hologram builder for Minecraft. It loads local schematic files and renders them as a translucent in-world guide, so you can line up a build, inspect missing or incorrect blocks, prepare materials, and work layer by layer without installing anything on the server.

What It Does

HoloBuilder focuses on planning and visual building:

• Load schematic files from holobuilder/schematics/.
• Preview the structure as an in-world hologram.
• Compare expected blocks with the current world.
• Highlight incorrect blocks in red.
• Optionally show already-correct blocks with subtle outlines.
• Move the placement relative to the direction you are looking.
• Rotate the schematic horizontally or vertically by 90 degrees around its center.
• Mirror the schematic directly in game.
• Work with one Y layer at a time.
• Preview required materials from the schematic selection screen.
• Compare required materials with your current inventory, hotbar, offhand, shulker boxes, and readable bundles/pouches.
• Export selected areas into supported schematic formats.
• Show, hide, or clear /holopos selections with configurable shortcuts.

The mod is client-side only. It does not need to be installed on the server.

Performance Warning

Very large schematics can still cause significant FPS drops or stutters while the hologram is visible, especially with high render-distance settings or complex block states. For the smoothest experience, lower HoloBuilder's render distance, use layer view, hide already-correct blocks, or split very large builds into smaller schematics.

Supported Files

The schematic selector currently accepts:

• .holo
• .litematic
• .schem
• .schematic
• NBT

The .schem, .schematic, and .litematic formats are NBT-based. HoloBuilder accepts compressed and uncompressed NBT imports. The native .holo format is recommended for the most reliable workflow, while unusual external files may still expose edge cases depending on their metadata and block states.

Basic Usage

1. Put schematic files in:

<game directory>/holobuilder/schematics/

1. Press H in game.
2. Select a schematic.
3. Click Load.
4. Move, rotate, mirror, or switch layers until the hologram is aligned.

No schematic is loaded automatically when joining a world.

Controls

Default keybinds :

• H: open schematic selector.
• G: toggle schematic rendering.
• Numpad 8 / 2: move forward/backward relative to your horizontal view direction.
• Numpad 4 / 6: move left/right relative to your horizontal view direction.
• Numpad 9 / 3: move up/down.
• Numpad + / -: rotate by 90 degrees.
• Numpad /: rotate vertically by 90 degrees.
• Numpad *: toggle mirror mode.
• Numpad 7 / 1: show higher/lower layer.
• X: show all layers.
• Numpad .: show or hide the /holopos selection without clearing it.
• Delete: clear both /holopos selection points.
• Numpad 5: reload the active schematic.

Selection And Export

HoloBuilder includes simple client commands for selecting and exporting a cuboid area:

• /holopos 1
• /holopos 2
• /holopos info
• /holopos clear
• /holo save <format> [name]
• /holo undo

Supported export formats:

• holo
• schematic
• schem
• litematic
• NBT

Exports are written to holobuilder/schematics/.

Creative Build Tools

HoloBuilder includes optional build assist tools for creative mode:

• B: direct-build all missing/incorrect blocks.
• V: toggle auto placer for the aimed hologram block.
• C: toggle full auto build for the aimed hologram block.

These tools are only available in creative mode and use normal Minecraft /setblock commands. On multiplayer servers, they still depend on server permissions and rules. HoloBuilder suppresses its own vanilla /setblock feedback spam locally, but it does not change world gamerules.

Survival gameplay remains visual-only: no automatic block placement is available there.

Compatibility

• Minecraft 1.21.1, 1.21.5, and 1.21.11
• Minecraft 26.1, 26.1.1, 26.1.2, and 26.2
• Fabric build available
• NeoForge build available
• Fabric API required for the Fabric build
• Server-side installation not required

Fabric and NeoForge are distributed as separate jar files. One shared 26.1.x file supports Minecraft 26.1 through 26.1.2. Use the file that matches your Minecraft version and mod loader.

Release Notes

The main schematic workflow is visual and client-side. It does not place blocks, modify the world, or require a server-side installation.

Creative build tools are optional and creative-mode only. They use normal Minecraft /setblock commands, so back up important worlds before using them on saves you care about.

Areas where reports are especially useful:

• unusual .litematic, .schem, and .schematic files
• complex block states
• large schematics
• multiplayer permission behavior
• loader-specific UI/rendering differences

Independent Project

HoloBuilder is an original independent project. It is not based on Litematica, does not reuse Litematica source code, does not copy its internal architecture, and does not depend on MaLiLib.

Join the official Discord: