Standstill

Based on game build 714014 | Last updated: 2026-03-03

Overview

StandStill is a behavior node used in the decision-making system of entities (e.g., AI characters) to enforce a stationary state. It inherits from BehaviourNode and halts the entity's movement by calling LocoMotor:Stop(). It optionally accepts two callback functions: startfn (evaluated on entry) and keepfn (evaluated while running) — if either returns false, the node fails; otherwise, it remains in the RUNNING state and periodically sleeps to avoid blocking the scheduler.

This component is typically part of a larger behavior tree and integrates with the locomotor component to control movement termination.

Usage example

local inst = CreateEntity()
inst:AddComponent("locomotor")

local standStillNode = StandStill(inst,
    function() return inst:HasTag("player") end,
    function() return not inst:HasTag("moving") end
)

-- Later, in behavior tree execution:
standStillNode:Visit()

Dependencies & tags

Components used: locomotor Tags: None identified.

Properties

Property	Type	Default Value	Description
inst	Entity	—	The entity instance to which this behavior applies.
startfn	function or nil	nil	Optional predicate function called when the node enters READY state; must return true to proceed.
keepfn	function or nil	nil	Optional predicate function called during RUNNING state; must return true to continue.

Main functions

Visit()

• Description: Executes the behavior logic. If the node is READY, it evaluates startfn; if true, it stops locomotion and transitions to RUNNING. While RUNNING, it evaluates keepfn each tick and sleeps for 0.5 seconds before re-evaluating. Fails if either callback returns false.
• Parameters: None.
• Returns: Nothing.
• Error states: None explicitly handled; behavior fails silently if callbacks return false or throw errors (due to lack of try/catch).

Events & listeners

• Listens to: None.
• Pushes: None — depends on the event system only through locomotor:Stop() (which pushes locomote), but does not push events directly.

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