Block Reality

What you need

Any launcher works — the vanilla launcher, Prism, MultiMC, Modrinth, CurseForge. Nothing else needs installing: no separate library, no runtime, no download at first launch.

Install

One file. The jar is the whole installation — the finite element engine travels inside it and unpacks itself the first time analysis is needed. If you installed an earlier version, read upgrading from 0.1a / 0.2a first.

1

Have a Forge 1.20.1 instance

Skip this if you already do. Otherwise create a profile: Minecraft 1.20.1, modloader Forge, any 47.x version.

3

Launch and check

Start the instance, load any world, press T and run:

/br status

On a fresh world with nothing built yet, you should get back:

The same thing as text:

Minecraft chat — /br status

Block Reality
  dimension       minecraft:overworld
  engine          IDLE
  engine: <game directory>\blockreality\engine\c4d571a5911b\br-sidecar.exe
  revision        0   (rejected as stale: 0)
  blocks          0   test loads: 0
  last result     none yet

• engine IDLE — found and waiting. Idle because there is nothing built yet.
• engine: — the binary it resolved to. See where the engine comes from. If this line is missing, /br status lists every path it searched instead.
• blocks 0   test loads: 0 — nothing structural in range.
• last result none yet — no solve has run.

The engine: line and the searched-path list only print for operators — they spell out filesystem paths, including the account name, which a non-privileged player on a server has no business reading. A single-player creative world has the permission already.

Now build something →

Where the engine comes from

Block Reality is still two programs — the mod reads your blocks and draws the HUD, and a separate process runs the finite element solve. What changed in 0.3 is that you no longer have to place the second one. It rides inside the jar and unpacks itself on first use to:

You put one file in. After the first analysis runs, the instance looks like this — the highlighted line is the only thing you placed:

.minecraft\
├── mods\
│   └── blockreality-0.3c.jar      ← you put this here
├── blockreality\
│   └── engine\
│       └── c4d571a5911b\
│           └── br-sidecar.exe   ← unpacked from the jar
├── config\
└── saves\

The folder is named after the binary's own SHA-256. Three things fall out of that: a mod update lands beside the old engine instead of overwriting it, a half-written file can never be mistaken for a good one, and nothing is ever downloaded — those bytes were already in the jar you installed, and anything whose hash does not match is refused rather than run.

The search order

It takes the first one that exists, most explicit first:

The three explicit settings come first so a path you chose is never quietly overridden. The bundled engine comes before the game directory on purpose: a loose br-sidecar.exe sitting there is most often one an older installer left behind, while the bundled one is guaranteed to match the jar that is running.

Upgrading from 0.1a or 0.2a

Delete the old blockreality-*.jar from mods/ before adding the new one — two copies of the same mod in mods/ is a load error.

The loose br-sidecar.exe that the old installer put in your game directory can stay or go. Either way it is no longer what runs: the bundled engine is found first, precisely so that a stale binary left by an older release cannot outrank the one that matches the jar you are running. Deleting it is tidier and costs nothing.

The installer scripts, if you want them

Optional. They do exactly what step 2 does — put the jar in mods/ — plus copy a loose engine next to it, and find mods/ for you if you would rather not go looking. They ship in the release archive on GitHub, not here, because the jar on its own is a complete install.

Extract the archive properly before running one: the script copies the files sitting next to it, so it needs the folder intact. Then on Windows double-click install.bat, or on Linux:

With no arguments it searches the usual instance locations for the vanilla launcher, Prism, MultiMC, Modrinth and CurseForge. One hit and it uses it; several and it lists them and asks. You can also name the directory:

To see what it found without installing anything:

  Block Reality - 安裝器 / installer
  ==================================

    1) [Forge]    C:\Users\you\AppData\Roaming\.minecraft
    2) [no Forge] C:\Users\you\AppData\Roaming\PrismLauncher\instances\survival\.minecraft
    3) [no Forge] C:\Users\you\curseforge\minecraft\Instances\block-reality

And a successful run:

  Block Reality - 安裝器 / installer
  ==================================

  mod    -> C:\Users\you\AppData\Roaming\.minecraft\mods\blockreality-0.3c.jar
  engine -> C:\Users\you\AppData\Roaming\.minecraft\br-sidecar.exe

  [OK] 這個實例裡有 Forge。用你平常的啟動器開遊戲就好。
       Forge found in this instance. Launch it the way you normally do.

  進遊戲後：創造分頁 "Block Reality"。有問題打 /br status。
  In game: creative tab "Block Reality". If anything looks off: /br status

Real output, with the account name replaced. The engine it copies is the loose one, which lands in the game directory — search position 5. The bundled copy inside the jar is still what actually runs.

Checking the download

The jar served here:

Also as a file, so you can check it in one command:

Or on Windows:

SHA256SUMS.txt — the same hash the GitHub release lists for this file.

Troubleshooting