Minecraft Crossover Bridge (Windows)

Minecraft inside Monster Hunter: World (Windows 11)

This is a Windows-native port of an existing project. Original: justbustin/minecraft-crossover-bridge by justbustin, which ran Minecraft inside Monster Hunter: World and Elden Ring on a Mac through CrossOver. The idea is his (and @tobynjacobs's); this repository is the same design rebuilt for native Windows 11, for Monster Hunter: World only. All original copyright stays with the original author: see LICENSE and the credits at the bottom.

What changed against the original:

• Elden Ring is removed. Its bridge, its Fabric mod and its scripts are gone, along with the

  macOS/D3DMetal notes.

• No CrossOver, no Wine, no Rosetta. The game already is a Windows x64 program, so the

  camera, raycast, entity and damage code is untouched; only the plumbing moved to Windows:

  • Shared memory is %MHWMC_DIR%\bridge.shm (%TEMP%\mhwmc by default) mapped with

    CreateFileMapping / FileChannel.map, instead of a file shared through Wine's Z: drive.

  • Built with MSYS2 MINGW64 (g++/make) instead of Homebrew's mingw-w64.
  • Scripts are PowerShell instead of zsh; the loader forwards dinput8 to

    %SystemRoot%\System32 and no longer needs a Wine DLL override.

  • The game must run on DirectX 11, which is what the bridge hooks.

Play real Minecraft (Java Edition 1.21.1 with Fabric) inside Monster Hunter: World on native Windows 11. The game runs as a normal Windows x64 process and Minecraft runs as a JVM, and the two talk to each other through shared memory while both are running.

You play as Steve, with Minecraft's controls:

• One picture. The game renders its world from Minecraft's camera, and Minecraft's blocks,

  mobs and hand are drawn into the game's own frame. They're hidden behind the game's walls and lit by its light.

• Real terrain. Steve walks on the game's actual collision: floors and walls are sampled

  from the game and become invisible blocks. You can build on top of them.

• Real fights. The game's monsters get Minecraft hitboxes. Swords, arrows, critical hits and

  TNT hurt them in the game, and tougher monsters take more hits. Their attacks hurt you in Minecraft.

• Switching. One key (F8) hands the keyboard and mouse to the game for its menus, map and

  quests, and back.

Supported game version: 15.23.00 (build 421810), the final PC patch.

Requirements

• Windows 11 (x64).
• MSYS2, using the MSYS2 MINGW64 shell:

  pacman -S --needed mingw-w64-x86_64-gcc make

• Two JDKs: Java 21 for Minecraft 1.21.1, Java 25 for Gradle and Fabric Loom. Gradle finds

  the Java 21 toolchain among the installed JDKs by itself.

• Monster Hunter: World 15.23.00, installed through Steam, with DirectX 12 turned off

  (DirectX12Enable=Off in graphics_option.ini).

• Python 3 if you want the debug tools. The game doesn't need it.
• The function keys must act as F1–F12.

Getting started

git clone https://github.com//minecraft-crossover-bridge-win.git
cd minecraft-crossover-bridge-win          # every command below runs from here

# build the bridge and install it into the game folder
powershell -ExecutionPolicy Bypass -File monster-hunter-world\scripts\install_mhw_bridge.ps1
# start MHW from Steam and get into an area (windowed, smaller than the screen), then:
powershell -ExecutionPolicy Bypass -File monster-hunter-world\scripts\run_minecraft.ps1

install_mhw_bridge.ps1 locates the game through Steam (including extra library folders); pass -GameDir "D:\...\Monster Hunter World" if it can't, and -Remove to uninstall. It builds the DLLs with MSYS2 (shell MINGW64), then copies dinput8.dll (the loader) next to MonsterHunterWorld.exe and mhwbridge\mhwbridge_core.dll into a subfolder. On Windows no registry override is needed: the game loads the dinput8.dll from its own folder. Use scripts\reload_core.ps1 to rebuild and hot-swap just the core while the game keeps running (changing the loader needs a restart).

Minecraft opens its own world ("MHW Bridge"). It covers the game window and takes over the keyboard and mouse once the game's character is in the world.

How it works

  Fabric mod (Minecraft 1.21.1)                        Monster Hunter: World (native x64)
  ──────────────────────────────                        ────────────────────────────────────
  Fabric mod  ─── camera pose, rendered frames ──▶       bridge DLL: the game renders from that pose,
                                                         Minecraft's pixels go into its frame
             ◀── terrain ray hits ───────────────       rays cast against the game's collision
             ◀── monsters: position, hitbox, HP ─       the game's own character and monster lists
             ─── hits on monsters ───────────────▶      damage applied with the game's functions
             ◀── hits on the player ─────────────       the hidden game character takes the hits
                  (shared memory: %MHWMC_DIR%, default %TEMP%\mhwmc)

• Two halves. A Fabric mod runs in Minecraft. A small Windows DLL is loaded into the game in

  place of dinput8.dll (forwarding to the real one in %SystemRoot%\System32), and it loads the actual bridge, which can be rebuilt and swapped while the game runs.

• Shared memory. Both sides map the same files in %MHWMC_DIR%: C++ with

  CreateFileMapping, Java with FileChannel.map. Set MHWMC_DIR to change the folder; both sides must agree on it.

• Camera. Minecraft owns the player. Each frame it sends its camera position and direction.

  The bridge overwrites the game's camera with it, so the game draws its world from where Steve stands.

• Drawing into the game's frame. Minecraft renders normally, copies its picture and depth into

  shared memory, and only then sends that frame's camera. When the game presents its frame, the bridge draws Minecraft's pixels into it. A per-pixel depth test against the game's depth buffer hides Minecraft's blocks behind the game's walls, and the brightness of the game's own image relights them.

• Terrain. Minecraft asks for batches of rays around the player. The bridge casts them

  against the game's own collision on the game thread, and every hit becomes an invisible block in Minecraft.

• Monsters and damage. The bridge publishes nearby monsters with their hitboxes and health.

  They become invisible Minecraft entities. Minecraft's hits go back into the game as damage, using the game's own functions. The game's character is hidden at Steve's feet as a stand-in: monsters target and hit it as usual, and those hits are passed to Minecraft as damage.

• Safety. Every game address the bridge uses is checked against its expected bytes at

  startup. If anything differs (another game version), that feature switches off instead of guessing. Game functions are only called from the game's own thread.

docs/how-it-works.md explains each part in more depth.

Repository layout

monster-hunter-world/     the bridge itself
  mhw-bridge/             Windows DLL (C++, MinHook hooks): loader + bridge core
  mc-bridge/              Fabric mod for Minecraft 1.21.1
  scripts/                install / run Minecraft / hot-reload the core / dev-commands
                          (PowerShell), plus the debug tools (Python 3)
windows-port/             notes and shared pieces from the port
  PORTING.md              what changed against the original, and why
  src/shm_win.h           native shared memory (CreateFileMapping), %MHWMC_DIR%
docs/                     how it works
AGENTS.md                 porting notes, invariants and traps for anyone changing this

scripts\common.ps1 holds what the PowerShell scripts share: the game-folder lookup through Steam, the MSYS2 build, the copy-then-rename install and the hot-reload request. The Python tools need Python 3, and only for development, not to play.

Caveats

• One game version. Features whose addresses don't match switch off. Only 15.23.00

  (build 421810) is supported.

• DirectX 11 only. The bridge hooks the D3D11 swapchain's Present. With DirectX 12 on it

  says so in the log and the compositor stays off.

• The bridge loads on every start once installed, since it replaces the dinput8.dll the game

  loads. Play solo: no online sessions or SOS flares while it's installed, since it changes monster health. Run install_mhw_bridge.ps1 -Remove to undo it.

• Fan project. It isn't affiliated with Mojang, Microsoft or Capcom. It contains no game files

  or assets, only short byte patterns used to recognize the game's code: the bridge works on your installed game at runtime. Use it at your own risk and back up your saves.

Credits

• Original project: justbustin/minecraft-crossover-bridge

  by justbustin — the design, most of the game-side reverse engineering and the Elden Ring port that this repository started from. The idea of putting Minecraft inside another game is @tobynjacobs's. This is an unofficial Windows port; please support the original.

• MinHook (BSD 2-Clause, vendored in the bridge's

  third_party/minhook) for the hooks.

• Fabric (Loom, Loader, API) for the Minecraft side.
• Community research the code cites:
  • SharpPluginLoader: Monster Hunter: World's

    projectile-creation parameters.

  • HunterPie: Monster Hunter: World's damage-number

    function and zone offsets.

License

MIT, © 2026 justbustin, as in the original project. MinHook keeps its own license (*/third_party/minhook/LICENSE.txt).