Chaseandram

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

Overview

Chaseandram is a BehaviourNode subclass responsible for orchestrating a target-chasing and ramming maneuver (e.g., a charging attack) for an entity. It coordinates movement via locomotor, triggers combat actions via combat, and enforces runtime limits based on time, distance, or number of attacks. It is typically used for boss or aggressive AI entities that must close distance before striking.

The node listens for onattackother and onmissother events to track attack attempts and resets pursuit timers accordingly. During execution, it adds the ChaseAndRam tag to the entity and removes it upon success or failure.

Usage example

local inst = CreateEntity()
inst:AddComponent("combat")
inst:AddComponent("locomotor")
inst:AddComponent("health")
inst:AddComponent("embarker") -- optional, affects platform-hopping logic

local chase_node = Chaseandram(inst, max_chase_time=5, give_up_dist=12, max_charge_dist=20, max_attacks=3)
chase_node:Visit() -- Called during AI update loop

Dependencies & tags

Components used: combat, locomotor, health, embarker (optional, used for platform detection)
Tags: Adds ChaseAndRam while running; removes on failure/success.

Properties

Property	Type	Default Value	Description
inst	Entity	—	The entity instance this behavior controls.
max_chase_time	number	—	Maximum time (seconds) allowed for the chase before aborting.
give_up_dist	number	—	Distance (squared threshold via distsq) beyond which the behavior fails if the target is missed while overshooting.
max_charge_dist	number	—	Maximum distance from start point allowed during the charge; exceeded → fail.
max_attacks	number?	nil	Optional limit on number of attacks; exceeded → succeed.
numattacks	number	0	Counter for successful attacks (incremented on onattackother/onmissother).
startruntime	number?	nil	Timestamp when the run began, used to enforce max_chase_time.
startloc	Vector?	nil	Position vector at start of charge.
ram_angle	number?	nil	Target angle for the ram (in radians).
ram_vector	Vector?	nil	Normalized direction vector of the ram.
onattackfn	function	—	Internal callback for onattackother and onmissother events.

Main functions

OnStop()

• Description: Cleans up event listeners and is called when the behavior is aborted or preempted (e.g., by a higher-priority node).
• Parameters: None.
• Returns: Nothing.

OnAttackOther(target)

• Description: Increments numattacks and resets startruntime (to delay time-based timeout). Called automatically on attack events.
• Parameters: target — the target entity involved in the attack (ignored; stored in data.target in event handler).
• Returns: Nothing.

AreDifferentPlatforms(inst, target)

• Description: Determines whether the entity and target are on different platforms (e.g., ground vs. floating). Checks embarker component if present.
• Parameters:
  • inst (Entity) — usually self.inst
  • target (Entity) — the target entity
• Returns: true if platforms differ and embarker exists; otherwise false.
• Error states: Returns false if embarker component is absent.

Visit()

• Description: Core behavior execution logic. Handles state transitions (READY → RUNNING → SUCCESS/FAILED) and movement logic. Must be called periodically by the AI system.
• Parameters: None.
• Returns: Nothing.
• Error states:
  • Immediately sets status = FAILED if target is invalid or missing at READY stage.
  • Sets status = SUCCESS if target dies mid-run.
  • Sets status = FAILED on timeout, distance limit, missed charge, or different-platform failure.
  • Resets ram_vector, stops locomotion, removes ChaseAndRam tag, and clears combat target on failure.

Events & listeners

• Listens to:
  • onattackother — tracked via onattackfn to count attacks and reset chase timer.
  • onmissother — also tracked via onattackfn (both events increment numattacks).
• Pushes: None (relies on combat:ForceAttack() and locomotor side effects to trigger further gameplay events).