RotRadarMinimap

Rot Radar Minimap

A toggleable, R.E.P.O.-style minimap for Grain Rot.

Grain Rot only shows you the dungeon layout on the physical map-room table and

on the end-of-run "Your Journey" screen. Rot Radar puts a live minimap in the

corner of your screen: the dungeon layout, your position and facing, your

teammates in their spark colors, and the spawn elevator.

Controls

| Input | Action |

|---|---|

| M | Toggle the minimap |

| Numpad + / - | Resize |

| Home / End / Delete / Insert | Nudge marker calibration (quarter-tile steps) |

| F9 | Debug info to the UE4SS console/log |

| F3 | Hide approximate (boxed) rooms |

| F4 | Draw in the dungeon's native orientation |

| F8 | Full map dump (ASCII) to the UE4SS console/log |

What you see

• White shapes — rooms and corridors, drawn from the dungeon

generator's own room grid, so the layout always matches the run

• Dim boxes — the game's hand-built special rooms (extract, hazard

rooms and friends), whose interiors the game never describes per-tile;

shown as a clean approximate area instead of a confident wrong shape

• Green square — the spawn elevator
• Orange marker — you (rotates with your facing; follows your Spark if

your vessel dies)

• Colored dots — your teammates, live, each in their chosen spark color

The whole map auto-rotates so the direction you face when you first step out

of the spawn elevator is up — every dungeon, every run, regardless of how

the generator spins the layout. The map has no backing panel and translucent

fills, so it stays readable without blocking your view of the game.

Installation

Install Mod Manager or r2modmanPlus — the

required UE4SS setup (GrainRot UE4SS + unreal shimloader) installs

automatically as dependencies. Press M in a dungeon.

Installing through the mod manager is strongly recommended — it handles the

UE4SS setup and updates for you.

Multiplayer

• Friends do not need the mod to play with you — nothing in the game

files is modified, so modded and unmodded players join each other freely.

• The map works whether you host or join: every machine generates the same

dungeon from the shared seed, and Rot Radar reads your local copy.

• Teammate markers work even if the teammates don't have the mod — their

positions and spark colors replicate natively; only you need the mod to

see them.

How it works (for the curious)

Rot Radar does not screenshot or unpack any game asset. It reads the dungeon

generator's replicated room grid (room and corridor tile footprints), rebuilds

the layout as a UMG overlay at runtime, and converts world positions into the

same tile grid — compensating for the per-run rotation the generator applies

to the whole dungeon.

Troubleshooting

• "no dungeon map available here" — you're in the outpost or between

runs; the map only exists during an active dungeon run.

• Marker slightly off-center from the corridors — tap

Home/End/Delete/Insert to nudge it (quarter-tile per tap); the offset shows

in the UE4SS log.

• Static transition hallways (some stair sections) don't appear — those

exist in no dungeon data; the map draws everything the generator knows.

Credits

• Runs on the GrainRot UE4SS

community overlay and RE-UE4SS.

• Minimap concept inspired by R.E.P.O.

Changelog

1.0.0

• Initial release: live self-rendered minimap with per-tile room footprints,

auto-rotation to spawn facing, teammate markers in spark colors, Spark

follow-through on vessel death, resize and calibration hotkeys.

1.0.4

• Contrast pass: darker, thicker outlines and stronger fills - readable even at max gamma, no backing panel needed
• Resize now also works on the main-row - / = keys (tenkeyless keyboards)
• Player marker has a white direction nose showing where you are facing

1.1.0

• Rooms are now drawn from the dungeon's real placed floor geometry, so

hand-built rooms show their true interior shape instead of a rough box

1.1.1

• Fixed the floor geometry from 1.1.0 being silently thrown away on many

dungeons, which made the