Patrol

Type: Exec (In → Out / Done)
Category: AI

Moves the owner object sequentially between 2–8 scene waypoints. Supports Loop (cyclic) and non-loop (stops at last waypoint) modes. Includes arrival braking when approaching each waypoint.

Properties

Property	Type	Default	Description
Waypoints	Int (2–8)	2	Number of active waypoints
WP 1 … WP N	Enum	(scene objects)	Waypoints in visit order
Speed	Float (≥0.01)	2.0	Patrol speed (units/s)
Arrive Radius	Float (≥0.1)	1.0	Distance to consider a waypoint reached
Loop	Bool	True	Return to WP1 after the last waypoint
Physics	Enum	Character	Object physics mode

Physics modes

Mode	Movement method
Character	applyMovement() in world space
Dynamic	Assigns localLinearVelocity.x/y (preserves Z)

Sockets

Socket	Direction	Type
In	Input	Exec
Out	Output	Exec (continuous)
Done	Output	Exec (when Loop=False and last WP reached)

Behavior

Arrival braking

Like Seek, Patrol uses an automatic braking zone before each waypoint:

arrive_zone = max(arrive_radius * 3, arrive_radius + 1.5)
arrive = clamp((distance - arrive_radius) / arrive_zone, 0, 1)

Persistent state

The node maintains self._pt_idx (current waypoint index) and self._pt_wps (name list). They are initialized only once.

Loop = True

On reaching the last waypoint, the index wraps back to 0:

self._pt_idx = (self._pt_idx + 1) % len(self._pt_wps)

Loop = False

On reaching the last waypoint, the index no longer advances. The Done socket fires.

Typical usage

Three-point loop patrol

Waypoints: 3
WP 1: Waypoint_A
WP 2: Waypoint_B
WP 3: Waypoint_C
Speed: 2.0
Loop: True

[OnUpdate] → [Patrol] → [Out: idle / other logic]
                 │
                Done: (never fires if Loop=True)

Patrol then Chase

[Distance Check: Player, Threshold=10.0]
    ├── Near ──► [Seek: Player]
    └── Far  ──► [Patrol]

Notes

• Empty waypoint slots are filtered out — if WP 3 is empty and Waypoints=4, only the 3 named ones are used.
• If all waypoints are invalid, the node does pass without error.
• Patrol operates on the XY plane — Z is ignored in direction calculation.
• _pt_idx persists while the object exists. To restart from the beginning, use a BTCustomTask: self._pt_idx = 0.
• Character physics velocity is multiplied by deltaTime() internally; Dynamic physics sets velocity directly.