59 — BP_PatrolPath

Blueprint Spec — UE 5.5–5.7

Parent Class

Actor

Dependencies

BP_EnemyBase — AI pawn using the path
BPC_AIControllerBase — Waypoint consumer
DA_AIProfile — Patrol behavior config

Purpose

Waypoint-based patrol route for AI characters. Defines a sequence of points (spline or actor array) that AI follows during patrol state. Supports looping, ping-pong, random selection, and conditional stops. Visualized in-editor with spline or point indicators for level designers.

Variables

Name	Type	Description
`PatrolPoints`	Array	World-space waypoints
`PatrolMode`	EPatrolMode	Sequence mode
`bIsLooping`	Bool	Restart from first after last
`bIsPingPong`	Bool	Reverse direction at end
`PointRadius`	Float	Acceptance radius for reaching a point
`WaitTimeAtPoint`	Float	Pause at each waypoint (seconds)
`bRandomizeOrder`	Bool	Shuffle points on each loop
`bUseSpline`	Bool	Draw spline between points
`SplineComponent`	USplineComponent	Optional spline path
`bDrawDebug`	Bool	Editor visualization toggle
`DebugPointColor`	FColor	Point color in editor
`ConnectedAI`	Array<BPC_AIControllerBase>	AI using this path

Enums

Enum	Values	Description
`EPatrolMode`	Sequential, Random, PingPong, Reverse	Point selection order

Functions

Name	Inputs	Outputs	Description
`GetNextPatrolPoint`	CurrentIndex: Int	FVector, NewIndex: Int	Next waypoint based on mode
`GetPatrolStartPoint`	—	FVector, StartIndex: Int	First point
`GetPatrolPointCount`	—	Int	Total points
`GetPatrolPointByIndex`	Index: Int	FVector	Specific point
`AddPatrolPoint`	Location: FVector	—	Add waypoint
`RemovePatrolPoint`	Index: Int	—	Remove waypoint
`ClearPatrolPoints`	—	—	Reset path
`SetPatrolMode`	Mode: EPatrolMode	—	Change movement pattern
`IsPatrolComplete`	CurrentIndex: Int	Bool	End of path
`RegisterAIUser`	AIController: BPC_AIControllerBase	—	Track who uses this path
`UnregisterAIUser`	AIController: BPC_AIControllerBase	—	Remove usage

Blueprint Flow

[GetNextPatrolPoint(CurrentIndex)]
  └─► If PatrolMode == Sequential:
         NewIndex = CurrentIndex + 1
         If NewIndex >= PatrolPoints.Num():
             If bIsLooping: NewIndex = 0
             Else: return Last point and IsPatrolComplete = true
  └─► If PatrolMode == Random:
         NewIndex = Random integer in range [0, Points.Num - 1]
         Exclude CurrentIndex to avoid standing still
  └─► If PatrolMode == PingPong:
         If going forward:
             NewIndex = CurrentIndex + 1
             If NewIndex >= PatrolPoints.Num(): reverse direction
         If going backward:
             NewIndex = CurrentIndex - 1
             If NewIndex < 0: reverse direction
  └─► If PatrolMode == Reverse:
         NewIndex = CurrentIndex - 1
         If NewIndex < 0:
             If bIsLooping: NewIndex = Points.Num - 1
             Else: IsPatrolComplete = true
  └─► Return PatrolPoints[NewIndex], NewIndex

Editor Visualization

[OnConstruction]
  └─► If bDrawDebug:
         For each point:
             DrawDebugSphere(Point, PointRadius, 12, DebugPointColor)
             If bUseSpline:
                 SplineComponent.SetSplinePoints(PatrolPoints, ESplineCoordinateSpace::World)
             Else:
                 Draw lines between consecutive points

Communications With

Target	Method	Why
`BPC_AIControllerBase`	Direct call	AI requests next waypoint
`BP_EnemyBase`	Direct (via controller)	Move-to destination
Level Designer	Editor visualization	Place and configure in world

Reuse Notes

World-placed actor, assignable to any AI via DA_AIProfile or direct reference
Multiple AI can share one patrol path (squad patrol)
Spline mode allows smooth curved paths (for flying/gliding enemies)
Works with any AI that reads patrol index from blackboard

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