Alert Spread¶

Overview¶

Alert Spread lets an agent that has a target in sight call the agents around it, so nearby allies react even though none of them saw anything themselves. In motion, one guard spotting the player turns into a whole room reacting within moments, instead of each agent only ever noticing what is directly in front of it. A call only tells a neighbour that a target exists. What moves it is Searching or Following The Crowd, and both are off in a new profile, so turn at least one of them on with this. Turn it on for any crowd that should feel coordinated, and leave it off when a single sighting should stay exactly that: one agent's problem.

Lives on the Perception Profile, and calling needs Sight on

This is a section of the archetype's Perception Profile asset, the same asset Sight and Awareness live on, not a field on the Behavior Profile. Unlike Following The Crowd and Searching, it does not depend on Approach & Press: a call is a direct write to a neighbour's perception state, not steering. Acting on a call is steering, though, and it comes from one of those two.

It does depend on Sight, though. An agent calls only while it can currently see the target, so an archetype with Sight off never calls, whatever this section is set to.

The Simple and Advanced grouping below is this page's own, not the inspector's. The Perception Profile has no mode switch and draws every field at once.

Parameter Reference¶

Simple Parameters¶

Start here: these three decide whether a call happens and who hears it

Enabled¶

This is the checkbox on the Alert Spread section header.

Visible effect: An agent that spots a target on its own calls the agents standing near it, so nearby allies learn about it even though they never saw anything themselves. They move on it only with Searching or Following The Crowd on. With both off, a called agent knows about the target and stays where it is, and the inspector warns about that with a button that turns Searching on.
Gameplay effect: The difference between a crowd of individuals that only react to what each one personally notices, and a crowd that reacts together the instant any one member spots the player.
Increase when: Not applicable, it is a toggle.
Decrease when: Not applicable, it is a toggle.
Pitfalls: A call only ever comes from an agent that can currently SEE the target. Being alerted by somebody else is never enough to pass the call on, so one sighting can ripple outward once, but it can never chain further than a single call's reach from wherever the target currently is.
Technical effect: Gates whether a detecting agent queues a call each step. Off, the perception pass still tracks Sight and Awareness normally for this agent, but nothing it notices ever reaches its neighbours.

Radius¶

Visible effect: How far a call carries from the calling agent, in units.
Gameplay effect: Decides how big a group wakes up from a single sighting: a tight cluster around the spotter, or most of a room.
Increase when: A single spotted intruder should wake a wide area at once, like an alarm going off.
Decrease when: Sightings should stay local, so only the agents right next to a spotter react.
Pitfalls: The real reach of this feature is bounded by Sight's Range plus this value, measured from the target rather than from the spotter, because a call only ever comes from an agent that can currently see the target. Raising Radius alone cannot let a call cross a gap wider than that bound.
Technical effect: Runs the same grid-radius stimulus query a scripted EmitStimulus uses, centred on the calling agent, and is stopped by walls whenever Occlusion is turned on for this profile, using the same navigation test Sight uses. A Radius of 0 turns Alert Spread off just as Strength 0 does. Only agents carrying a Perception Profile respond, and the caller is never one of the agents it reaches.

Strength¶

Visible effect: How convinced a called neighbour becomes. At full strength it becomes as certain as if it had spotted the target itself; lower values leave it less sure.
Gameplay effect: One call lasts Strength times Forget Time on the agent that hears it, since its awareness fades at the normal Forget Time rate from wherever this sets it. Every repeat call sets it back, so a lower value makes called-in agents give up sooner only once no caller still sees the target.
Increase when: An alerted crowd should react and commit as if every member had personally seen the target.
Decrease when: Called-in agents should react but visibly less committed, and drop the alert sooner than the one that actually spotted the target.
Pitfalls: 0 turns Alert Spread off just as completely as unchecking Enabled, but the checkbox still reads on, which is easy to miss while tuning.
Technical effect: Sets the awareness value written to a called agent, but only raises it, never lowers it below what the agent already has. That value then fades toward 0 at the profile's normal Forget Time rate like any other awareness level.

Advanced Parameters¶

Power-user knob: leave at defaults unless you have a reason

Interval¶

Visible effect: How often one agent can call again while it keeps seeing the target continuously. An agent that has been quiet for a full Interval calls as soon as it reacts to the target, which for a first sighting is after Acquire Time. One that called a moment ago and re-spots it waits out the rest of the cooldown first.
Gameplay effect: Each repeat sets a called agent's awareness back to Strength and moves the spot it remembers to where the target is now. A short Interval keeps called agents close behind a moving target. A long one leaves them walking to where the target was at the last call.
Increase when: A dense crowd all watching the same target shows up in the profiler from repeated calls.
Decrease when: Called agents trail a moving target, or stop and start because a call wears off before the next one arrives. One call lasts Strength times Forget Time on the agent that hears it, and one caller repeats every 0.75 to 1.25 times Interval. At the defaults that is 0.7 x 3 = 2.1 seconds of call against a repeat every 1.1 to 1.9 seconds, so the next call arrives in time. Raise Interval or lower Strength far enough and an agent with a single caller in earshot forgets the target between calls. The inspector warns when the numbers fall that way.
Pitfalls: 0 does not make calls reach further or wake more agents. It only means an agent that is already calling repeats every single step instead of waiting, which wakes nobody new and still pays for a full query each time. In a crowd packed around one target, where every agent is calling, that multiplies the cost of the whole perception step, so it is the most expensive field on this page by a wide margin.
Technical effect: Cooldown seconds before the same agent can queue another call. Each agent's interval is varied a little by a fixed per-agent factor, so a crowd that spots something on the same step does not then call in lockstep forever after. A call costs per agent it reaches rather than per call, so the same Radius costs more in a packed crowd than in a spread one. The number of calls that go out in one step is capped whatever the crowd does, and the rest are dropped silently, which is why a mass reveal cannot spike without bound.

Practical Usage Guidance¶

Turn this on for guard groups, packs, or any crowd that should feel like it communicates: one spotted intruder waking a room is what makes stealth failure feel like a real consequence instead of a private mistake for one agent. It pairs naturally with Sight's Occlusion: set that to Navigation Path and a call respects the same walls Sight does, so an alarm in one room does not wake the next one over.

Walls need a Surface Flow Field at Smooth or Eikonal quality

This applies once Sight's Occlusion is set to Navigation Path, which is what makes walls matter to a call in the first place. The test reads the integration field, and only the Smooth and Eikonal bake qualities keep one. On Cardinal, or with no baked field in the scene, the test cannot resolve and the call is not sent at all, which fails toward silence rather than toward waking a room through a wall. Nothing is logged, so a room that refuses to wake is worth checking against the bake quality before the radius. With Occlusion left at None there is no test and calls go out whatever the quality.

Skip it for solo enemies and bosses, since there is nobody nearby to call. Skip it too for a stealth game where a single sighting should stay that one agent's problem rather than spreading, or for any archetype with Sight turned off, since it will never call regardless of this section.

Gameplay Interpretation¶

Radius decides how contagious a sighting is: small keeps a mistake local, large turns one spotted player into a room-wide response. Strength decides how convinced the crowd looks once alerted: high reads as a coordinated, fully-briefed response, low reads as allies reacting on a rumour that fades fast if nobody confirms it.

Quickstart: tune in this order

Tick the checkbox on the Alert Spread header and confirm Sight is on for this archetype, since a call needs an agent that can actually see something. Turn on Searching or Following The Crowd too, or the agents it calls will not move.
Set Radius to how far a single sighting should spread, keeping in mind it adds on top of Sight's Range.
Set Strength below full if called-in agents should feel less certain than the one that actually spotted the target.
Raise Interval if a dense, fully-alerted crowd shows up in the profiler, and lower it if called agents trail a moving target or the inspector warns that a call wears off before the next one.