Guide

Coming from AI Perception#

APS runs beside Unreal's AI Perception, so you can move across one behaviour at a time. A typical guard takes 20 to 40 minutes.

The 30-second version

Room W1, In the Dark. The same thief walks the same dark path past two guards. APS: he slipped by. Unreal AI Perception: caught in the dark, because it ignores light.

Add an APS Core to the AI's Pawn, give it a profile, and leave AI Perception where it is.
Move sight first: On Target Perception Updated becomes On AI Detect, On AI Lost and On AI Forget.
Report Noise Event becomes Emit Sound with a Sound Type asset. Damage needs nothing: it's wired automatically.

One behaviour at a time#

APS doesn't disable or change AI Perception; both can run and both fire their events.

Add APS beside your setup.
Move one behaviour (usually sight).
Check it, then unbind the AI Perception version.
Repeat for hearing, damage and the rest.
Remove the AI Perception component once nothing is bound to it.

What maps to what#

AI Perception	APS
AI Perception component	APS Core component, on the Pawn
Sight config	Vision Sense in `Sense Classes`, and the profile's Detection settings
Hearing config	Hearing Sense, and a Sound Type Definition per kind of noise
Damage config	Damage Sense: every Unreal damage call, no reporting needed
Touch config	Touch Sense: hits and overlaps are wired automatically
Prediction config	`Enable Prediction` (Spatial)
Team config	Squads: Set Squad ID and Share Target with Squad
Sight Radius	`Vision Max Range`
Lose Sight Radius	`Vision Loss` grace time and how belief fades (below)
Peripheral Vision Half Angle	`Vision Half Angle Deg`, plus a real side cone if you want one
Detection by Affiliation	The APS Relationship component
Max Age	How belief fades: `Default Decay Exponent`, `Memory Expire Threshold`, `Min Time in Lost`
On Perception Updated	On Target State Changed, or the separate state events
On Target Perception Updated	On AI Detect, On AI Lost
Get Currently Perceived Actors	Get Targets Sorted by Score, keeping the states you count as perceived (Detected and Tracked, say): it lists everyone it holds a slot for, including targets not noticed yet, Lost or Remembered
Get Actors Perception	Get Belief Data
Request Stimuli Listener Update	Not needed: APS updates on its own interval
Report Noise Event	Emit Sound, Emit Sound at Location
Report Damage Event	Nothing: damage is automatic
Gameplay Debugger's perception page	`Show Visualizer` on the APS Core (Visualizer)

The port, step by step#

1. A profile from your sight settings. Content Browser › Miscellaneous › Data Asset › Perception Profile (DA_Profile_YourAI). Copy Sight Radius to Vision Max Range and Peripheral Vision Half Angle to Vision Half Angle Deg; replace Detection by Affiliation with an APS Relationship component. Everything else has a working default.

2. Add the component. On the AI's Pawn: APS Core, with the profile. Its events are on the component (select it, Details › Events, +); for reactions several AI share, use an APS Perception Listener Blueprint (Getting started). Leave AI Perception in place for now.

3. Move sight across.

BEFORE
  On Target Perception Updated (Actor, Stimulus)
    └─► Branch: Stimulus › Successfully Sensed
          True  → set the target
          False → clear the target

AFTER
  On AI Detect (Target, Threat Level, Stimulus) → set the target
  On AI Lost (Target, Last Known, …)            → start searching
  On AI Forget (Target)                         → clear the target

That is already an upgrade: one true/false flip becomes three moments: it has you, it lost you (with a reason and a last known position), and it gave up.

4. Move hearing across.

BEFORE  Report Noise Event (Location, Loudness 1, Instigator, Max Range 800)
AFTER   Emit Sound (Source: Self, Sound Type: DA_Sound_Footstep)

Loudness, range and how alarming it is live on the asset, not the call: tune every footstep in the game from one place. Hearing

5. Remove the old component once nothing is bound to it. Nothing in APS depends on it.

What has no direct equivalent#

Room W2, Head Above the Wall. The thief hides with his head showing over a wall. APS saw his head (one of five points). Unreal AI Perception, tracing to the body's centre, never saw him.

Lose Sight Radius. AI Perception sees you inside one radius and loses you outside a larger one. APS isn't true/false, so it has no second radius. Losing you is governed by:

Setting	Default	Role
`Vision Loss` › Grace Time	0.3	Seconds with no sight before it drops you
`Vision Loss` › Confidence Decay Multiplier	3	How fast belief falls after that
`Default Decay Exponent`	0.3	The base fade
`Min Time in Lost`	0	The least time it searches before giving up

If your Lose Sight Radius was much bigger than Sight Radius ("keep tracking after they've gone"), raise the grace time to 1 to 1.5 s and Min Time in Lost to 5 to 10.

Auto Success Range from Last Seen Location. A workaround for AI Perception's single trace. APS doesn't need it: partial cover gives partial confidence, all the time.

Max Age. AI Perception ages stimuli out on a timer; APS fades belief and frees the slot when confidence drops below Memory Expire Threshold. For a hard timer, use Min Time in Lost with a steep Default Decay Exponent.

Dominant Sense. AI Perception lets one sense override another's location. APS combines them: the strongest sense sets the confidence, and the position comes from whichever active sense places the target most precisely. A gunshot beats a vague scent with no configuration.

Room W3, He Hid. The thief ducks behind a crate. The APS guard remembers where and why it lost him and searches that cover: found him. The Unreal guard goes back to its post: he got away.

What feels different#

You'll notice	Because	To change it
Detection isn't instant	Confidence builds	Raise `Confidence Rise Rate`
It keeps looking where you were	The vision grace time	Lower `Vision Loss` grace to 0.1
Partial cover matters	Five points per target	See the parity profile below
It no longer sees through doors	If you set occlusion channels	The fix most people came for
The cone lags the body	Only with `Eye Turn Rate Deg Per Sec` above 0	0 snaps instantly
Sense events fire a lot	On AI See and the other sense events fire each time a sense reports	Use the state events (On AI Detect and the rest) for one-off reactions

A profile that behaves like AI Perception#

For a strict baseline before tuning, start close to AI Perception, check parity, then turn features on one at a time, so any change in behaviour traces to one setting:

Setting	Value
`Sense Classes`	Vision Sense and Hearing Sense only
`Vision Sample Count`	1
`Eye Direction Mode`	Control Rotation
`Eye Turn Rate Deg Per Sec`	0
`Confidence Rise Rate`	10
`Suspect Threshold`, `Detect Threshold`, `Track Threshold`	0.05, 0.10, 0.15
`Telegraph Threshold`	0.08 (keep it between Suspect and Detect)
`Vision Loss` › Grace Time	0
`Use Per Target Light`	Off
`Corroboration Bonus`	0
`Enable Prediction`	Off
`Max Fear`, `Max Aggression`, `Max Curiosity`, `Max Alertness`, `Max Panic`	0

With an APS Target Component on the target, its own Visibility Samples are used and Vision Sample Count is ignored. Trim that list to one entry, or leave the component off, while you check parity.

Checklist#

A profile, with Vision Max Range and Vision Half Angle Deg copied over
APS Core on the Pawn, profile assigned
Sight moved to On AI Detect, On AI Lost, On AI Forget
Report Noise Event replaced with Emit Sound, a Sound Type for each kind of noise
Affiliation replaced with APS Relationship
Show Visualizer used to check the cones and confidence
Occlusion channels set: the reason most people move
AI Perception removed