Houndbrain

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

Overview

HoundBrain is a brain component responsible for orchestrating hound AI behavior through a behavior tree. It handles core tasks such as following or hunting players, eating corpse food (non-mutated hounds), attacking walls when leaderless, returning to home base, and entering/remaining in statue form for clay hounds or abandoned pets. The behavior differs significantly between pet_hound, clay hounds, and mutated (lunar_aligned) hounds, and it integrates with components like combat, follower, homeseeker, eater, and burnable to make context-aware decisions.

Usage example

local inst = CreateEntity()
inst:AddTag("hound")
inst:AddComponent("brain")
inst.components.brain:SetBrain("houndbrain")
-- Behavior will activate automatically upon stategraph entry

Dependencies & tags

Components used: combat, follower, homeseeker, eater, burnable
Tags: Checks pet_hound, clay, lunar_aligned; uses INLIMBO, outofreach, NOCLICK, fire, creaturecorpse, statue

Properties

Property	Type	Default Value	Description
carcass	Entity or nil	nil	Stores the currently selected valid carcass entity for consumption.
reanimatetime	number?, true, or nil	nil	Internal timer used to delay and trigger reanimation for clay hounds or abandoned pets (value true indicates ready to reanimate).

Main functions

SelectCarcass()

• Description: Finds and selects a valid non-mutating creature corpse within SEE_DIST (30 units) for consumption. Used for non-mutated hounds.
• Parameters: None.
• Returns: boolean — true if a valid carcass is found and stored in self.carcass; false otherwise.

CheckCarcass()

• Description: Validates that the currently stored self.carcass is still usable: not burning, still valid, tagged as creaturecorpse, and not mutating.
• Parameters: None.
• Returns: boolean — true if self.carcass passes all checks.

GetCarcassPos()

• Description: Returns the world position of the validated carcass, or nil if the carcass is invalid or unready.
• Parameters: None.
• Returns: Vector3? — World position of the carcass if valid; otherwise nil.

OnStart()

• Description: Initializes and assigns the root behavior tree node based on hound type (clay vs. standard vs. mutated). It constructs complex PriorityNode/WhileNode/ChaseAndAttack/Leash/Wander trees tailored to the hound's state and tags.
• Parameters: None.
• Returns: Nothing. Sets self.bt with the constructed BT instance.

Events & listeners

• Listens to: None directly (behavior tree handles state transitions via nodes).
• Pushes: becomestatue, reanimate, chomp — conditionally triggered during statue transitions, reanimation, and carcass eating, respectively.