Eyeofterrorbrain

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

Overview

EyeOfTerrorBrain is the AI behavior tree implementation for the Eye of Terror boss entity. It orchestrates complex combat behaviors such as ranged chomp and charge attacks, spawning and focusing mini-eyes, and maintaining positional constraints (leashing) using the leash and faceentity behaviors. The brain is initialized once per instance and constructs a hierarchical behavior tree (BT) in OnStart, leveraging the behaviours/faceentity and behaviours/leash modules.

Usage example

local inst = CreateEntity()
inst:AddComponent("brain")
inst.components.brain:SetBrainClass(EyeOfTerrorBrain)
inst:DoTaskInTime(0, function()
    inst.components.brain:OnInitializationComplete()
    inst.components.brain:OnStart()
end)

Dependencies & tags

Components used: combat, commander, knownlocations, timer
Tags: None identified (behavior tree actions fire events, but no tags are directly added/removed by this brain).

Properties

Property	Type	Default Value	Description
_leash_pos	Vector3 or nil	nil	Cached leash position; reset on entering special-move logic.
_special_move	string or nil	nil	Name of the current special move action selected by ShouldUseSpecialMove.

Main functions

ShouldUseSpecialMove()

• Description: Determines and prioritizes the next special action (spawn mini-eyes, focus mini-eyes on target, charge, or chomp) based on current game state and timers. Sets _special_move and returns true if a move is available; otherwise returns false.
• Parameters: None.
• Returns: boolean — true if a special move should be executed; false otherwise.
• Error states: Returns false if none of the attempt functions (TrySpawnMiniEyes, TryFocusMiniEyesOnTarget, etc.) return a valid move string or action token.

GetLeashPosition()

• Description: Calculates or retrieves the current leash target position, ensuring the boss maintains a fixed distance (7 units) from the combat target while avoiding jitter (caches position for 3 seconds via timer).
• Parameters: None.
• Returns: Vector3 — the calculated leash position.
• Error states: If no combat target exists, returns the boss’s current position.

OnStart()

• Description: Builds and assigns the behavior tree root node (self.bt) with logic for special moves, leashing, facing the target, and wandering.
• Parameters: None.
• Returns: Nothing.
• Error states: None; assumes combat, commander, knownlocations, and timer components are present.

OnInitializationComplete()

• Description: Records the entity’s current position (flattened to y=0) as "spawnpoint" in the knownlocations component, ensuring consistent spawn alignment.
• Parameters: None.
• Returns: Nothing.
• Error states: None; uses safe y-flattening and the dont_overwrite=true flag.

TrySpawnMiniEyes(inst)

• Description: Helper function to check if spawning mini-eyes is valid — only when cooldown timer "spawneyes_cd" does not exist and current soldier count is below the desired threshold.
• Parameters: inst (Entity) — the Eye of Terror entity.
• Returns: "spawnminieyes" if valid; nil or false otherwise.

TryChompAttack(inst)

• Description: Checks if a chomp attack is possible — only when transformed and the target is within chomp range (TUNING.EYEOFTERROR_ATTACK_RANGE).
• Parameters: inst (Entity).
• Returns: "chomp" if within range; false otherwise.

TryChargeAttack(inst)

• Description: Checks if a charge attack is possible — cooldown "charge_cd" must be expired, target must exist, and distance must be between minimum and maximum thresholds.
• Parameters: inst (Entity).
• Returns: "charge" if conditions met; false otherwise.

TryFocusMiniEyesOnTarget(inst)

• Description: Determines if mini-eyes should be focused on the current target — requires cooldown "focustarget_cd" to be expired, a target present, and minimum soldier count (TUNING.EYEOFTERROR_MINGUARDS_PERSPAWN) met.
• Parameters: inst (Entity).
• Returns: "focustarget" if conditions met; false otherwise.

Events & listeners

• Pushes: spawnminieyes, focustarget, charge, chomp — fired when ShouldUseSpecialMove() selects and executes a special move via self.inst:PushEvent(self._special_move).
• Listens to: None identified — this brain does not register external event listeners; behavior is driven by the behavior tree state and timer checks.