CoB RealGrass
Grass finally matters to the AI.
In vanilla Arma 3 the AI ignores ground clutter completely — a sniper prone in a waist-high meadow is, to the AI, lying on a billiard table. CoB RealGrass fixes that for players and AI, in singleplayer and real multiplayer (dedicated servers, headless clients, JIP), with a system built for compatibility and near-zero overhead.
Tier 1 — Camouflage gradient (always on). Every managed unit continuously receives an engine-native camouflage coefficient computed from the actual ground clutter at its position — density AND height, read from the terrain’s own configs, so it works on any map: vanilla, CDLC or community. Stance fit (prone hides in 30 cm grass, crouching needs ~85 cm), movement, bushes, moon-corrected darkness, NVG-equipped hostiles, weather, ghillie suits and indoor cover all factor in. Because it multiplies the engine’s own spotting model, distance, optics, skill and target motion still behave exactly like vanilla — close AI can still spot you, distant AI cannot.
Tier 2 — Deep hide. Prone in genuinely covering vegetation, unexposed, with no hostile nearby? An invisible view-geometry blocker makes you completely invisible to AI. Bullets still pass — suppressive fire can still find you.
Exposure. Firing spikes a smoothly-decaying exposure value instead of a binary cooldown. Suppressors help (detected from weapon configs — no class lists), muzzle flash hurts at night, launchers reveal you instantly, and recovery is gradual.
CoB RealGrass is a ground-up successor to Hide Among The Grass (HATG), rebuilt around one key idea: viewblocks are local objects, created only on machines that own AI hostile to the hidden unit. Nothing is synced over the network. The result:
- DUI Squad Radar, ACE Nametags, IR lasers and addAction menus keep working — the entire class of conflicts that plagued globally-synced viewblocks is designed out
- Zero network traffic and zero JIP queue from the concealment system
- AI hides in grass too — enemy snipers get the same treatment, managed on whatever machine owns them (server, HC or client)
- Gradient concealment instead of all-or-nothing invisibility
- Terrain-agnostic grass detection (no hardcoded surface lists — reads CfgSurfaces clutter data)
- One bounded scheduler per machine — no per-unit script loops, no remoteExec in any hot path
- CBA_A3
- Arma 3 v2.10 or later
- Must run on the server and all clients
~35 CBA settings (Options → Addon Options → CoB RealGrass): operating mode (hybrid / gradient only / viewblock only), who gets managed, concealment strength, vegetation strictness, darkness/NVG/weather factors, deep-hide threshold and close-range, exposure decay, equipment lists, full HUD customisation and debug tools.
Keybinds (Options → Controls → Configure Addons): toggle your concealment (default Shift+Ctrl+G), toggle the status HUD.
Full API and settings reference ship in the mod folder (docs).
- ACE — unconscious handling, no damage-chain tampering (medical-safe)
- LAMBS / danger.fsm — fully compatible
- DUI Squad Radar / ACE Nametags — unaffected by design
- HATG / ACSTG — conflict: running two concealment systems double-hides units. RealGrass detects them and warns.
Known limitation: on a player-hosted (listen) server the host machine owns hostile AI, so deep-hidden friendlies get a local viewblock on the host — only the host’s own radar/laser view is affected. Dedicated servers and SP are untouched.
Unscheduled, event-driven, cached config lookups, hard per-tick evaluation budget (default 3 units / 0.25 s — configurable). Cost is bounded no matter how many units are on the map.
- Concept ancestry: Hide Among The Grass[github.com] by Silence & MaxxLite (APL-SA) — the viewblock LOD trick is theirs; this mod is a from-scratch reimplementation with a new architecture.
- CoB RealGrass by Clan of Brothers.
Licensed under APL-SA[www.bohemia.net]. Source and the full asset toolchain (model and texture generators) are included in the mod folder.
