A crowd of pedestrians for your city (npc.pedestrian) #

Civilians who walk the sidewalks, run from fast vehicles and can be hit by them. The NPC documents, behaviours and perception they are built on are described in the NPC guide. Readable offline: gripforge docs npc-pedestrian, or the MCP tool gripforge_docs (topic npc-pedestrian).

What it is for #

npc.pedestrian fills a city with ordinary npc.core NPCs (faction civilian, behaviours wander, flee and idle), placed on the sidewalk nodes of world.roads once world.ready fires, and keeps count of them alive (a replacement is placed 20 seconds after one is removed). It turns vehicle danger into behaviour: a vehicle faster than 20 km/h within fleeRadius makes the civilians around it flee; a vehicle that sweeps through one, or a vehicle.collided with one, hurts it (speed x 5 health), throws the body and panics everyone within fleeRadius. It does not drive vehicles, run police or score anything: other kits read the npc.hit event for that. Its presentation module draws the blood of a hit pedestrian (droplets and ground stains) when bloodEffects is on.

Turn it on #

gripforge_gamekit_install   { project_id: "gkp_…", id: "npc.pedestrian" }
gripforge_gamekit_configure { project_id: "gkp_…", id: "npc.pedestrian",
                              config: { "count": 20, "fleeRadius": 10 } }

It requires npc.behavior (so npc.core), world.roads and game.engine. The model comes from the asset slot pedestrian (a rigged character, several allowed, picked at random); until one is bound a capsule is drawn.

First example #

<!-- test: kits/game_engine/host/tests/parity.rs::rust_host_matches_the_typescript_traces --> The fixture npc.pedestrian.hooks of that test plays five pedestrians on eight sidewalk nodes and these rules, which a game or a mod declares as data:

{ "id": "curfew", "hook": "pedestrian.spawn", "match": { "reason": "replace" },
  "if": [ { "var": "city.curfew", "op": "==", "value": true } ], "cancel": true, "reason": "curfew" }
{ "id": "truce", "hook": "pedestrian.hit",
  "if": [ { "var": "city.truce", "op": "==", "value": true } ], "cancel": true, "reason": "truce" }
{ "id": "soft_bumpers", "hook": "pedestrian.hit",
  "if": [ { "var": "city.soft", "op": "==", "value": true } ], "mul": { "damage": 0.5 } }

While city.curfew is true no replacement pedestrian is placed; while city.truce is true a vehicle hurts nobody and nobody panics; with city.soft the damage of a hit is halved.

Settings and defaults #

All of them are open to mods, except bloodEffects, which stays the game's own choice. A scene can override count and fleeRadius in its layer for this kit; leaving a scene removes its crowd and entering the next one places a new crowd.

Services, events, hooks #

• pedestrian.ai (service): pedestrians() the ids of the living pedestrians, panic(at, radius, from?) makes the civilians around a point flee and answers how many.
• npc.hit (event): { npc, entity, by, speed, position, direction, lethal, blood }, a vehicle by hit a civilian at speed m/s; blood is true when bloodEffects is on and the impact is at least 3 m/s. A wanted-level kit uses it as a heat source.
• vehicle.speed, vehicle.collided, world.ready, npc.despawned (events listened to).
• pedestrian.spawn (hook): { reason, x, y, z } before a pedestrian is placed; reason is crowd, replace or recycle; cancellable.
• pedestrian.hit (hook): { npc, by, speed, damage } before an impact is applied, at most once a second for the same pair; damage is mutable; cancellable (no damage, no knockdown, no panic).

Hooks and modding #

Rules like the ones above can be added by a game or a mod; a mod can also change the settings listed as moddable (for example a smaller count). A value out of range is clamped or refused by the kit validation.

Engines #

The crowd logic is the same Rust code on the web, natively and in the engine wrappers; the model, animation and blood are drawn by each engine from the npc.impact state and the npc.hit event.

When it does not do what you expect #

• No pedestrians: the world has no road network or no sidewalk nodes (the log says world.roads has no sidewalk nodes), npc.behavior is not installed, or count is 0. Without a model bound to the pedestrian slot a capsule is drawn and the project is not reported playable.
• Pedestrians never run: the vehicle is slower than 20 km/h, farther than fleeRadius, or does not publish vehicle.speed.
• A pedestrian is never hit: vehicleImpacts is off, the speed is below the impact threshold, or a pedestrian.hit tap cancels it.
• A killed pedestrian comes back: the kit replaces it after 20 seconds to keep count alive.

Limits #

The crowd lives on the sidewalk nodes of world.roads; it does not cross roads by itself, enter buildings or react to anything other than vehicles. Wanted levels, police and scoring belong to other kits.

Versions #

Kit 1.7.0; service pedestrian.ai 1.0.0. 1.7.0 added the pedestrian.spawn and pedestrian.hit hooks.