Trigger

The Trigger class extends Actor and creates a shape-based volume in the world that detects when other actors overlap it. Triggers are useful for gameplay logic like entering zones, starting scripted events, teleporting players, or detecting proximity. Supported shapes include spheres, boxes, and capsules.

tip

Trigger is an Actor, so it inherits all functions from Actor.

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Constructor

Blueprint

Blueprint— Spawn Trigger ActorScroll to zoom · Drag to pan · Drag nodes to move

Lua

-- Spawn a sphere trigger
local trig = Trigger(
    Vector(0, 0, 200),        -- location
    Rotator(),                 -- rotation
    Vector(100),               -- extent (radius for sphere)
    TriggerType.Sphere,        -- trigger shape
    true,                      -- visible (debug shape)
    function(self, other)      -- callback on overlap
        print(other:GetName())
    end,
    Color(1, 0, 0, 0.5)       -- debug color
)

JavaScript

// JavaScript follows the same pattern.
// Refer to the Lua examples for constructor parameters.

Constructor Parameters

Name	Type	Default	Description
Location	Vector	(0,0,0)	World position for the trigger.
Rotation	Rotator	(0,0,0)	World rotation.
Extent	Vector	(100,100,100)	Shape extents (radius, box half-size, or capsule radius/height).
TriggerType	enum	TriggerType.Sphere	Shape of the volume -- Sphere, Box, or Capsule.
bVisible	boolean	false	If true, draws a semi-transparent debug shape.
CallbackFunction	function	Required	Function called on actor overlap. Receives (self, otherActor).
Color	Color	(0,1,0,0.5)	Debug color if visible.
OverlapOnlyClasses	table	{}	Optional array of UClass paths to restrict overlap (e.g., only "/Script/Engine.Pawn").

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Examples

Safe Zone

Blueprint

Blueprint— Safe Zone Trigger with Overlap EventScroll to zoom · Drag to pan · Drag nodes to move

Lua

-- Create a safe zone trigger
local safe_zone = Trigger(
    Vector(0, 0, 0),
    Rotator(),
    Vector(2000, 2000, 500),
    TriggerType.Box,
    true,
    function(self, other)
        print(other:GetName() .. " entered the zone")
    end,
    Color(0, 1, 0, 0.3)
)

JavaScript

// JavaScript follows the same pattern.
// Refer to the Lua examples for constructor parameters.

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note

When bVisible is set to false (the default), triggers are invisible in-game and have no visual representation. Set bVisible to true during development for debugging purposes.