REPOPathfinder
A BepInEx plugin for R.E.P.O. that renders an in-world dot trail along the NavMesh path to the current extraction point — or back to the truck once all extractions are complete. It mirrors the same target-selection logic the in-map "backtrack" dots use, projected into world space so you can follow it without opening the map.
Hotkeys (configurable, all default to F-keys):
- F4 — toggle the trail on / off.
- F5 — switch the destination between Auto (game-driven: current extraction, or truck when all are complete) and Truck (forces the truck regardless of extraction state, for going back to charge items mid-run). Choice persists.
- F6 — open the customization panel: RGBA color sliders, hex input, color presets, and live sliders for dot size / flow speed / spacing. Edits write back to the BepInEx config so they persist across sessions.
What the DLL actually does
On plugin Awake(), it:
- Reads its config. A standard BepInEx config file (
BepInEx/config/isaia.repopathfinder.cfg) defines all hotkeys, dot visuals, animation tunables, and the path-recompute threshold. A [Internal] ConfigVersion key migrates stale defaults from prior versions in place — values that exactly match a previous default get overwritten with the current default; user-customized values are left alone.
- Creates a
DontDestroyOnLoad GameObject. Adds two MonoBehaviours to it: PathfinderManager (path / animation / rendering) and PathfinderCustomizeUI (the F6 IMGUI overlay).
- Installs Harmony input-blocking patches.
InputBlocker is gated on a single static BlockInput flag flipped by the customize UI; it is inert when the menu is closed. While the menu is open, the following are short-circuited so cursor movement doesn't drive the camera and clicks don't fire weapons:
- Legacy:
UnityEngine.Input.GetAxis, GetAxisRaw, GetMouseButton, GetMouseButtonDown, GetMouseButtonUp — return 0f / false.
- New:
UnityEngine.InputSystem.InputAction.ReadValue<T>() for Vector2, float, and Vector3 — return default(T). Bound dynamically via reflection, so the plugin still loads if the new InputSystem assembly is absent.
Input.GetKey / GetKeyDown / GetKeyUp are deliberately not patched, so F4 / F5 / F6 keep working.
Path computation
The path is cached in world space, not recomputed every frame:
- Target resolution. Auto mode:
RoundDirector.allExtractionPointsCompleted (read by reflection) → LevelGenerator.LevelPathTruck.transform.position; otherwise RoundDirector.extractionPointCurrent.transform.position. Truck mode: always LevelPathTruck. Identity is the ExtractionPoint reference or the literal string "truck".
- Recompute trigger. A new path is computed only when:
- There is no cached path yet,
- The target identity changed (different extraction, or Auto↔Truck flip),
- The player has drifted further than
OffPathRecomputeThresholdMeters (default 3.0) from the cached polyline (closest-point-on-line-segment over each cached segment), or
- A scene change invalidated the cache.
- Compute & cache.
NavMesh.CalculatePath(playerNavmeshPos, targetPos, AllAreas, path) is called once. The corners and prefix arc-distances are stored; the displayed dots reference these stable world-space points for as long as the cache lives. playerNavmeshPos is PlayerAvatar.LastNavmeshPosition (read by reflection — internal field).
- Each frame. The player is projected onto the cached polyline to produce a
playerArc scalar; that's the trail's "back end". Walking forward changes only playerArc; the cached corners are untouched, so dot world positions stay stable regardless of how the player moves.
Animation & rendering
- A pool of
MaxDots (default 30) sphere primitives, colliders stripped, sharing one material with per-dot color set via MaterialPropertyBlock.
- A single shared
_animOffset ∈ [0, spacing) advances by FlowSpeed m/s. When it crosses spacing the circular pool pointer _frontPool decrements, which makes every sphere's slot index increment by 1 simultaneously. Spacing stays perfectly even regardless of how availableLength = totalLength - playerArc changes.
- The single sphere whose slot wraps from
MaxDots-1 to 0 per cycle has its smoothing flag cleared in the same step, so it snaps to its new position at the player end of the trail instead of being lerped across the room.
- World position per dot:
CachedPointAtDistance(playerArc + slot*spacing + animOffset), plus GroundOffset on Y. The result is exponentially smoothed toward the displayed position with rate PositionSmoothRate (default 25 1/s) for the rare cases where the path is re-cached.
- Alpha fade per dot:
min(SmoothStep(0..fadeZone, d), SmoothStep(0..fadeZone, endpoint-d)) where d = slot*spacing + animOffset, endpoint = min(availableLength, MaxDots*spacing), fadeZone = spacing * FadeZoneFraction. Hides the wrap and the path's own ends behind alpha-0 transitions.
- Material shader is resolved at runtime via
Shader.Find("Sprites/Default") ?? Shader.Find("Unlit/Color") ?? Shader.Find("Standard"). _ZWrite 0 and SrcAlpha/OneMinusSrcAlpha blend are set if the chosen shader exposes those properties; render queue is 3500.
Customization UI
PathfinderCustomizeUI (default F6) is a draggable GUILayout.Window:
- RGBA sliders (0–255 readout),
#RRGGBBAA text field with Apply, preview swatch over a white underlay so transparency is obvious, eight color presets.
- Sliders for
DotScale, FlowSpeedMetersPerSec, SpacingMeters.
- Reset Visuals writes each of the above ConfigEntries back to its
DefaultValue. Close dismisses the panel.
- All edits go straight to the BepInEx ConfigEntries.
PathfinderManager subscribes to DotColorHex.SettingChanged so the cached _baseColor refreshes the moment a slider moves; size / flow / spacing are read from config every frame and update for free.
- On open: cached
Cursor.lockState and Cursor.visible are saved, then forced to None / true so the cursor is interactable. On close: the saved values are restored. InputBlocker.BlockInput is flipped in lockstep with visibility.
Install
Thunderstore Mod Manager: click Install. Manual: drop REPOPathfinder.dll into <profile>/BepInEx/plugins/REPOPathfinder/. Requires BepInEx-BepInExPack.
Compatibility
- Client-side. The plugin is purely local: it reads
PlayerController.instance.playerAvatarScript, RoundDirector.instance, and LevelGenerator.Instance to compute its own path and renders its own GameObjects. No RPCs, no Photon traffic. Each player can install independently; nothing about the plugin requires the host or other clients to have it.
- No Harmony patches on REPO code. Harmony prefixes target only
UnityEngine.Input (legacy) and UnityEngine.InputSystem.InputAction.ReadValue<T>() (new). REPO's own classes are read via reflection (for internal fields) but are never patched.
- No NavMesh modifications. The plugin calls
NavMesh.CalculatePath for itself; it does not bake or alter the game's NavMesh.
Changelog
0.7.2
- Ported the InputBlocker pattern from REPOBlacklist so dragging customize-panel sliders no longer rotates the camera or fires weapons. Harmony prefixes on legacy
Input.* axis / mouse-button reads and on InputAction.ReadValue<Vector2/float/Vector3>() (bound via reflection); GetKey* deliberately untouched so hotkeys still work.
0.7.1
- Fixed long-path "conveyor belt" rubber-banding: when
activeCount == MaxDots, the wrapping dot's slot transitioned MaxDots-1 → 0 while staying inside the visible branch, so the smoothing lerp animated it across the entire trail length. The frontPool decrement now also clears _wasVisible for the pool index that just wrapped, forcing a snap.
0.7.0
- Added the F6 customization UI: RGBA sliders, hex input, eight color presets, dot-size / flow-speed / spacing sliders, Reset Visuals, all live-bound to the BepInEx ConfigEntries.
PathfinderManager subscribes to DotColorHex.SettingChanged and refreshes its cached _baseColor immediately, so dragging color sliders updates world dots on the same frame.
0.6.0
- Added F5 destination toggle: Auto (game-driven extraction → truck) and Truck (force truck regardless of extraction state). Mode is persisted as a
PathfinderTargetMode ConfigEntry. Cache invalidated on toggle so the trail re-orients on the next frame.
0.5.0
- Replaced per-frame recompute with a cached path + per-frame player projection. Path is recomputed only on target identity change or when the player drifts more than
OffPathRecomputeThresholdMeters from the cached polyline. Walking forward / backward along the path no longer translates dot world positions at all — the dots are nailed to absolute world coordinates; only their visibility shifts as the player walks past them.
RecalcIntervalSeconds is now deprecated and ignored.
0.4.0
- Added per-dot exponential-decay smoothing on world positions (
PositionSmoothRate, default 25). _wasVisible flags reset on every path recompute and on hidden→visible transitions so wraps still snap rather than draw a curved interpolation across geometry.
0.3.0
- Replaced per-dot independent
d %= trailExtent wrap with a shared _animOffset plus circular pool pointer _frontPool. Spacing now stays perfectly even regardless of how availableLength changes; previously a moving modulo divisor could shake dots off the spacing grid.
- Added config-version migration: stale
DotColorHex / DotScale defaults from 0.1 / 0.2 are overwritten with the new defaults; user-customized values are preserved.
0.2.0
- Added continuous flow animation:
_animOffset advances every frame and the trail recycles continuously instead of populating-then-disappearing in waves.
- Switched per-dot color updates to a single shared material plus
MaterialPropertyBlock for alpha fade.
- Smaller / more translucent default dot visuals.
0.1.0
- Initial implementation: F4 toggle, NavMesh path computation from
PlayerAvatar.LastNavmeshPosition to RoundDirector.extractionPointCurrent (or LevelGenerator.LevelPathTruck when all extractions are complete), primitive sphere pool with Sprites/Default material at render queue 3500.
