Stealth_Overhaul_Reworked_v5.7

Complete stealth overhaul for STALKER Anomaly (GAMMA-compatible). Based on the classic addon «Stealth 2.0.1» (by xcvb), extended with a full package of new stealth mechanics: noise, detection feedback, silent takedowns and a redesigned detection formula.

Features

Core (from Stealth 2.0.1)

• Reworked NPC vision: luminosity, distance, movement velocity, carried weight, outfit/camouflage, crouching and stance all affect how well NPCs see you.
• Custom detection meter (eye icon) and debug HUD.
• Weight-based stealth: the heavier you are, the easier you are to see.
• Camouflage values (npc_blindness_koeff) per outfit.
• Full MCM integration with per-option tuning.

New mechanics (this package)

• Footstep noise system (stealth_noise.script)
  • Realistic noise radius: crouch 3 m, walk 10 m, run 20 m, sprint 30 m.
  • Noise scales with total weight, outfit noise_k stat, breathing (wounded / low stamina / bleeding), and is reduced by rain.
  • Artifacts alter your noise signature (e.g. af_gravi ×1.2, af_fireball ×1.3, af_compass ×0.75).
  • NPCs investigate noise (threat_danger logic / danger system) — subtle sounds make them curious, loud ones alert them.
  • Dropping items makes noise (10 m).
• Squad alarm propagation (visual_memory_manager.script)
  • When an NPC spots you, nearby squad members (within 200 m, MCM squad_alert_range) get an alarm boost (×1.6 detection, MCM squad_alert_dur).
  • Monsters that see you alarm nearby stalkers (MCM monster_alarm_radius, default 150 m; MCM monster_alarm_dur). Both radii/durations are configurable live — set to 0 to disable.
• NPC muzzle flashes (ported from NPC's can't see through foliage 1.8.2)
  • NPCs that fire a non-silenced weapon become highly visible for 0.2 s (×7 detection) — you can spot shooters in the dark.
• Terrain-dependent camouflage (ported from NPC's can't see through foliage 1.8.2)
  • Ghillie outfits only grant their camo bonus on natural terrain (earth, dirt, grass, bush), tracked via the actor_on_footstep callback.
• Dynamic campfire lighting (ported from NPC's can't see through foliage 1.8.2)
  • NPCs/monsters standing within 7 m of a burning campfire get +0.4 luminosity — targets near fires are easier to spot (no longer a static constant).
• Detection feedback HUD (stealth_ui.script)
  • Eye meter: white (undetected) → amber (suspicion / alarm) → red (spotted).
  • Noise bar to the right of the eye icon shows your current noise radius as a vertical meter (green = quiet → yellow → red = very loud). Can be hidden independently via MCM noise_bar while keeping the noise system active.
  • Eyesight is not persistent: your detection accumulates, then calms down along a smooth exponential curve (fast drop right after losing sight, gentle tail) — roughly halved every 2.5 s.
  • Companions are excluded from the meter: any NPC traveling in your squad (escorts/companions) never turns the eye red or amber, even when their goodwill is not FRIENDS.
• Dual HUD icon (light_gem.script, ported from Stealth 2.31)
  • Two modes selectable in MCM (icon_type): "Light indicator" (classic light gem) or "NPC vision" (progress bar — white normal, yellow combat/danger, red spotted).
  • Icon position is fully configurable in MCM (icon_x / icon_y).
• NPC NVG system (stealth_nvg.script, ported from Stealth 2.31)
  • Higher-rank stalkers may own NVGs (experienced/professional 20%, veteran/expert 50%, master 85%, legend 100%) — at night they show a visible red dot at the eye and turn off their headlamp.
  • NPCs that own NVGs see better at night (nvg_val multiplier); toggle with npc_nvg, disable entirely with nvg_val = 0.
• Night vision & light interactions
  • NPC night adaptation: in dark zones, NPCs coming from bright areas take a moment to adjust (×0.6 detection).
  • Your own flashlight pointed at an NPC's back massively blinds them (×0.55, marks them as suspicious).
  • Guards/snipers on watch are less perceptive (×0.5); searching NPCs are more perceptive (×1.5).
• Scent system — mutated animals track you by blood: the more you bleed, the farther they smell you (up to ~60 m).
• Community perception — factions perceive you differently (Duty 1.2, Military 1.25, Renegades 0.9, Ecologists 0.85…).
• Silent takedowns (stealth_takedown.script)
  • Crouch, knife equipped, sneak behind an NPC who hasn't noticed you → the next knife swing is a silent kill.
  • Kills fire the same callbacks as Stealth Kill Detection Fix (npc_on_death_callback with the weapon as killer so NPCs don't aggro, plus npc_on_silent_kill_callback and the silent_kills statistic) — quests, loot and stats see your silent kills. Safe pcall guards make this a no-op if the fix isn't installed.
  • Hide corpses: crouch and look at a dead body for 1.5 s to remove it from the world (no alarm, no detection).
• Danger system refinement (xr_danger.script)
  • Dangers caused by the player persist longer and are never ignored by distance.
  • Hidden corpses no longer trigger danger events.

Requirements

• STALKER Anomaly 1.5.1+ (works with GAMMA)
• MCM (optional but recommended — without it the defaults in stealth_mcm.script are used)

Installation

1. Copy the gamedata folder into your Anomaly root directory (overwrite when asked).
2. If you use GAMMA/MO2: install the archive as a normal mod or place gamedata manually.
3. Launch the game — the mod is configured by default with all new mechanics enabled.

The included files override parts of the base stealth files. If you use another stealth mod, install only one of them.

Configuration (MCM)

Options → Mod Configuration Menu → Stealth

Option	Default	Description
memory	1.0	How fast NPCs forget you after losing sight
luminocity	1.0	Overall effect of light/darkness on detection
distance	1.0	Effect of distance on detection
velocity	1.0	Effect of movement speed on detection
weight	1.0	Effect of carried weight on detection
crouch	0.4	Detection multiplier while crouched
low_crouch	0.25	Detection multiplier while crouched + slow movement
icon	ON	Show the detection eye / noise bar HUD
icon_type	1	HUD icon mode: 1 = light indicator (gem), 2 = NPC vision (progress bar)
icon_x	970	Icon X position (0–1000)
icon_y	650	Icon Y position (0–1000)
nvg_val	1.0	Night-vision multiplier for NPCs that own NVGs (0 disables the NVG system, 0–3)
michiko_patch	OFF	Alternative (harsher) night-time luminosity curve
debugx	OFF	Debug printing for the target NPC under your crosshair
logging	ON	Write the dedicated log file (logs/stealth_overhaul.log)
noise	ON	Enable the footstep noise system
noise_bar	ON	Show the blue noise-level bar under the HUD icon (hide it without disabling the noise system)
noise_scale	1.0	Global noise radius multiplier (0.5–3)
noise_handoff	ON	Delegate hostile footstep alerts to AlifeTactics when installed (no double alerting)
scent	ON	Mutants smell your blood
glare	ON	Flashlight blindness / backlight glare
adaptation	ON	NPC eyes adapt between light and dark zones
community	ON	Faction-specific perception
npc_nvg	ON	NPCs with active NVGs see better at night
takedown	ON	Enable silent knife takedowns
hide_corpse	ON	Enable corpse hiding (crouch + stare 1.5 s)
monster_alarm_radius	150 m	Radius: monsters that spot you alarm nearby stalkers (0 = disabled, 0–300)
monster_alarm_dur	4 s	Duration of the monster alarm boost (0–10 s)
squad_alert_range	200 m	Radius: squadmates of a spotting NPC get an alert boost (0 = disabled, 0–500)
squad_alert_dur	3 s	Duration of the squad alert boost (0–10 s)
at_disclosure_gate	ON	When AlifeTactics is installed: squadmates only learn your position after an attack if they see you or are already fighting you (no "magic" squad-wide reveal)

Files

gamedata/scripts/
├── stealth_log.script           Dedicated log file (logs/stealth_overhaul.log)
├── stealth_noise.script          Noise system, NPC registry, suspicion, squad/monster alerts
├── stealth_ui.script             Detection eye, monster alert
├── stealth_takedown.script       Silent kills, corpse hiding
├── stealth_nvg.script            NPC NVG system (rank-gated, eye dot particle, headlamp off)
├── light_gem.script              Dual HUD (light gem / NPC vision bar, movable icon)
├── visual_memory_manager.script  Core detection formula (overrides Stealth 2.0.1)
├── camp_lum.script               Dynamic campfire lighting (campfire recalc timer)
├── trans_outfit.script           Empty stub for `timer_trans` (bind_stalker compatibility)
├── xr_danger.script              Danger system, actor-related dangers
├── xr_combat_ignore.script       Safe-zone fix
└── stealth_mcm.script            MCM options

gamedata/configs/
├── ai_tweaks/xr_danger.ltx       Danger inertion/ignore values (actor sections added)
├── creatures/m_stalker.ltx       Footstep/vision tuning for stalkers
├── creatures/m_stalker_zombied.ltx  Zombied vision tuning (vision_free / vision_danger)
├── ui/ui_light_gem.xml           HUD statics (gem, gem_bar, det_eye, noise_bar)
├── ui/ui_light_gem_16.xml        HUD statics (16:9)
├── ui/ui_light_gem_21.xml        HUD statics (21:9)
└── text/eng+rus+spa/ui_st_stealth.xml  Localized strings

gamedata/particles/stealth_nvg/nvg_dot.pe  NVG eye dot particle
gamedata/textures/ui/lightgem/eye.dds           Detection eye texture
gamedata/textures/ui/lightgem/eye2.dds          NPC vision bar texture
gamedata/textures/ui/lightgem/circle.dds        Noise/vision circle texture
gamedata/textures/ui/lightgem/bar_noise.dds     Noise bar track (empty state, blue->green gradient)
gamedata/textures/ui/lightgem/bar_noise_fill.dds White fill for the noise bar (tinted green/yellow/red)

Compatibility

Fully compatible with the GAMMA Alife pack — no shared files, no callback conflicts:

• xlibs 1.8.4 — no interaction (library only).
• AlifePlus 1.8.6 — no interaction (NPC lifecycle management; this mod's ID-based registry tolerates its spawn/despawn churn).
• AlifeBalance 1.1.3 — no interaction (smart/squad balance only).
• AlifeGuard 1.3.1 — no interaction (NPC guarding/sanitizer).
• AlifeTactics 1.1.6 — designed-in coexistence:
  • AT patches the winning xr_danger at runtime (function-level, on_game_start). This mod's xr_danger.script/xr_danger.ltx are the VFS winners and expose everything AT probes (actid, DangerIgnoreActor, the seven patched entry points), so AT's danger scheme runs on this mod's config values.
  • Hidden corpses never trigger danger, even under AT: the suppression now lives in a global npc_on_eval_danger subscriber (stealth_takedown.script) that fires under vanilla, this mod's, or AT's danger evaluator.
  • Footstep noise: when AT's movement-noise is enabled, hostile stalkers' footstep alerts are delegated to AT (no double set_script_danger stamping); this mod keeps its HUD noise bar, item-drop noise, monster alarms and neutral-NPC investigation. Toggle with the MCM noise_handoff option.
  • Hit-disclosure gate (stealth_noise.script): AT's at_disclosure force-injects the shooter into the whole squad's memory on the first faction-enemy hit — even when nobody saw or heard the attack. This mod wraps xcombat.disclose_enemy (AT's only disclosure entry point, resolved live at call time) so that actor-initiated disclosures only go through when the squad member can actually see the actor or is already fighting him. NPC-vs-NPC disclosures and all non-actor callers pass through untouched; the return value is only used for counting in AT, so a suppressed disclosure breaks nothing. Toggle with the MCM at_disclosure_gate option (default ON).
  • AT's own at_noise handles reload/item-use sounds; this mod handles item drops — complementary.

Note: mods that ship their own visual_memory_manager.script (e.g. NPC's can't see through foliage 1.8.2 DLTX, GAMMA's Atmospherics/Stealth Crash Fix) are mutually exclusive with this mod's copy — give this mod higher priority in MO2. The foliage vision itself works via DLTX configs and is unaffected.

Balance tuning tips

• Too hard to sneak? Lower noise_scale, disable npc_nvg / adaptation / community, or raise crouch values in MCM.
• Too easy? Set noise_scale to 1.5–2 and lower crouch to 0.3/0.15.
• Outfit noise stats are read from the noise_k line in the outfit section (add it to any outfit to make it quieter/louder).

Changelog

2026-08-09 — v5.7: companions excluded from the detection meter + independent noise-bar toggle

• Companions never light the detection eye (stealth_ui.script): is_ally_of_actor now also treats any NPC traveling in the actor's squad (escorts/companions) as an ally — they no longer turn the eye red/amber or contribute to the meter, even when their goodwill to the actor is below FRIENDS. Squad detection is checked via get_squad() with pcall guards (no squad → falls back to the goodwill check).
• New MCM option noise_bar (default ON) + localized strings (EN/RU/ES): the blue noise-level bar under the HUD icon can now be hidden independently (light_gem.script) while the footstep noise system keeps working.

2026-08-08 — v5.6: no magic squad knowledge (AlifeTactics hit-disclosure gate)

• New MCM option at_disclosure_gate (default ON) + localized strings (EN/RU/ES). When AlifeTactics is installed, AT's at_disclosure force-injects the shooter into the whole squad's memory on the first faction-enemy hit, even when nobody saw or heard the attack. This mod wraps xcombat.disclose_enemy (AT's only disclosure call site, resolved live at call time — covers hit, redisclose and inherit paths) so actor-initiated disclosures only reach squad members who can actually see the actor or are already fighting him. NPC-vs-NPC disclosures and all non-actor callers pass through unchanged; the return value is only used for counting in AT, so suppression is side-effect free. Verified: no other mod in the GAMMA pack calls disclose_enemy, pcall guards on see()/best_enemy() prevent dead-object crashes.

2026-08-08 — v5.5: configurable alarm radii

• New MCM options (stealth_mcm.script): monster_alarm_radius (0–300 m, default 150), monster_alarm_dur (0–10 s, default 4 s), squad_alert_range (0–500 m, default 200), squad_alert_dur (0–10 s, default 3 s). The monster alarm (stealth_ui.script) and the squad alert (visual_memory_manager.script) now read them live every tick — no restart needed; setting a radius to 0 disables the respective system entirely.

2026-08-08 — v5.4: full compatibility with the GAMMA Alife pack

• Hidden-corpse danger suppression is now universal (stealth_takedown.script): moved into a global npc_on_eval_danger subscriber. It fires no matter which xr_danger wins the VFS — vanilla, this mod's copy, or the AlifeTactics runtime patch — so a hidden corpse never makes NPCs react. The internal check in xr_danger stays as reinforcement.
• Footstep noise cooperates with AlifeTactics (stealth_noise.script): auto-detects AT at runtime (at_mcm + danger_move_noise). When AT's movement-noise is active, hostile stalkers inside this mod's noise radius are skipped (AT stamps them with its own radii) — no double set_script_danger. Item drops, monster alarms, HUD noise bar and neutral-NPC investigation remain this mod's own. New MCM option noise_handoff (default ON) forces this mod's full system when disabled.
• New MCM option noise_handoff + localized strings (EN/RU/ES).
• Verified against xlibs 1.8.4, AlifePlus 1.8.6, AlifeBalance 1.1.3, AlifeGuard 1.3.1, AlifeTactics 1.1.6: no shared files, no callback collisions, AT probes (actid, DangerIgnoreActor, entry points) satisfied by this mod's xr_danger.

2026-08-08 — v5.3: stability fixes (verified on MT-TEST build 10039)

• Fatal dead-NPC crash fixed (visual_memory_manager.script): npc_on_before_hit now guards npc:alive() and only reads the pending-hit record when it exists, before calling npc:see(db.actor) — an NPC that dies and hits the actor on the same tick (e.g. a bloodsucker's death attack) no longer crashes the engine with cannot check visibility of dead object / GetAttitude.
• Dedicated log made resilient (stealth_log.script): the log path is now resolved through three candidates ($logs$ virtual path → appdata/logs → fs_root/appdata/logs) with get_log_path() as a last resort; a nil config value counts as enabled (only false disables); if the path or io.open fails, a one-time !StealthOverhaul: diagnostic is printed into xray_*.log instead of failing silently.
• MCM robustness (stealth_mcm.script): get_config falls back to the built-in defaults when ui_mcm.get returns nil (option not registered / bad path) — no more nil-index errors on startup.
• Verified live: all stealth scripts load with zero errors and logs/stealth_overhaul.log is created and written.

2026-08-07 — v5.2: allies no longer detect the player

• Allied NPCs are excluded from the stealth system (stealth_ui.script, visual_memory_manager.script, stealth_noise.script): a stalker whose goodwill to the actor is >= game_relations.FRIENDS no longer contributes detection to the eye icon, never accumulates vis_acc in the detection formula, and won't investigate the player's noise or get alarmed by monsters spotting him. Only enemies, neutrals and hostile mutants still detect you.
• Detection icon now only reacts to non-allied NPCs; allied squads nearby no longer trigger amber/red states.

2026-08-07 — v5.1: fix — NPCs in alert when standing still

• Fixed (stealth_noise.script): when the player was standing still, compute_radius() fell through to the run branch (20 m), so NPCs within 20 m of the player were put into alert (threat_danger) every 250 ms — most visible right after loading a save near friendly NPCs. The radius is now 0 when the player isn't moving (mcAnyMove), and movement states are mapped in the correct order (sprint 30 m, crouch-walk 3 m, walk 10 m, run 20 m).

2026-08-07 — v5: localization & HUD defaults

• Russian translation rewritten (text/rus/ui_st_stealth.xml): fixed garbled machine-translated strings (mojibake), full retranslation of every option and description.
• Spanish translation cleaned (text/spa/ui_st_stealth.xml): accents removed from all strings to avoid encoding issues in-game.
• Default HUD icon position changed from 700/700 to 970/650 (stealth_mcm.script defaults + MCM sliders), and the light-gem statics in ui_light_gem.xml / ui_light_gem_16.xml / ui_light_gem_21.xml were repositioned and resized (24×32) to match the 21:9/16:9/16:10 layouts.
• Validated in-game: full session (Cordon, quicksave) with zero errors from all stealth scripts.

2026-08-06 — v4: engine-native improvements

• Event-driven NPC registry (stealth_noise.script): online_npcs is now maintained via the engine's game_object_on_net_spawn / game_object_on_net_destroy callbacks (NPCs/monsters added/removed instantly, online/offline switching included) instead of waiting for the periodic 5 s db.storage scan — the periodic refresh remains as a safety fallback.
• Noise-radius debug visualization (stealth_noise.script): with the MCM debugx flag ON, the current noise radius is drawn in-world via the Modded Exes debug_render API (translucent blue sphere around the actor).
• Fixed xr_combat_ignore.script: the stalker-vs-military Cordon distance rule compared comm twice instead of ene_comm (comm == "stalker" and comm == "army" → ene_comm == "army").

2026-08-06 — v3: takedown crash fix

• Fixed a fatal error in stealth_takedown.script (attempt to index local 'obj' (a boolean value)) that crashed the game on actor_on_update: the takedown/hide-corpse loops iterated the NPC registry values as objects, but the registry stores true markers (id → true). Both loops now resolve the NPC via level.object_by_id(id) like stealth_noise/stealth_ui, and alive() returns false for non-object values.
• The ID-based registry rule now holds across all scripts: NPCs are tracked by ID only and resolved on demand — destroyed objects can never crash a callback.

2026-08-06 — v2.31 features ported

• NPC NVG system ported from Stealth 2.31: rank-gated NVG ownership, visible eye-dot particle at night, NVG owners switch off their headlamp (sr_light patch). Works on Anomaly 1.5.2 and 1.5.3.
• Dual HUD ported from Stealth 2.31: icon_type (light indicator / NPC vision bar) + movable icon (icon_x/icon_y) — replaces the fixed light gem (light_gem_mcm.script removed).
• The night-vision detection boost in visual_memory_manager.script is now gated by actual NVG ownership (npc_nvg + stealth_nvg.has_nvg) instead of applying to every NPC.

2026-08-06 — Stability rewrite (v2)

• Rewrote stealth_noise.script, stealth_ui.script and stealth_takedown.script around an ID-based registry: NPCs are tracked by ID only and resolved on demand via level.object_by_id() — destroyed objects can never crash a callback.
• Only real engine callbacks are registered (actor_on_update, actor_on_item_drop); nonexistent ones (npc_on_binder_online/offline, actor_on_bolt_throw) were removed.
• Fixed a fatal level shadowing bug in noise_at() (parameter hid the global level table) that crashed on item drop / disconnect.
• Added alive() guards to the detection-eye loop so dead-but-not-destroyed NPCs are skipped (fixes "cannot check visibility of dead object" spam).
• Bolt-throw noise removed — the actor_on_bolt_throw callback does not exist in Anomaly; item-drop noise (10 m) remains.

Credits

• xcvb — original Stealth 2.0.1 addon
• Alundaio — NPC muzzle flash, terrain camo and campfire lighting ported from NPC's can't see through foliage 1.8.2 DLTX
• Addon page: https://www.moddb.com/mods/stalker-anomaly/addons/stealth1

Note: if you use NPC's can't see through foliage 1.8.2 DLTX alongside this mod, disable its visual_memory_manager.script (or give this mod higher priority in MO2) — both files are mutually exclusive. The foliage vision itself works via DLTX configs and is unaffected.