Pigbrain

Based on game build 714014 | Last updated: 2026-02-27

Overview

Pigbrain is a Brain component that defines the behavior tree for pig entities (including NPC contestant pigs). It orchestrates decision-making across multiple contexts: day/night cycles, leadership loyalty, trader interactions, minigame spectating, threat responses, and environmental navigation. The component uses behavior tree nodes (PriorityNode, WhileNode, DoAction, Follow, ChaseAndAttack, RunAway, Wander, Panic, FindLight, AvoidElectricFence) and integrates with several key components: Combat, Eater, Follower, HomeSeeker, Inventory, Trader, Health, Hauntable, Pinnable, and MinigameSpectator.

Usage example

local inst = TheWorld:SpawnPrefab("pig")
inst:AddBrain("pigbrain")
-- The brain is automatically started when the entity is added to the world
-- It manages actions based on state such as time of day, nearby threats, and loyalty

Dependencies & tags

Components used:

• burnable (IsBurning)
• combat (HasTarget, InCooldown, TargetIs)
• eater (CanEat, GetEdibleTags, TimeSinceLastEating)
• edible (foodtype)
• follower (GetLeader, GetLoyaltyPercent)
• hauntable (panic)
• health (takingfiredamage)
• homeseeker (home, GetHomePos)
• inventory (FindItem, GetItemByName, Has)
• minigame (gametype, watchdist_min, watchdist_target, watchdist_max)
• minigame_spectator (GetMinigame)
• pinnable (IsStuck)
• shelf
• timer (TimerExists)
• trader (IsTryingToTradeWithMe)

Tags: None explicitly added or removed by this brain. Pig entities use tags from other systems (e.g., "player", "spider", "pig", "NPC_contestant", "CHOP_workable", "lightsource", etc.).

Properties

Property	Type	Default Value	Description
inst.brain_noveggie	boolean or nil	nil	Temporary flag set during food search to restrict diet to meat only under certain satiety conditions; cleared after search.

Main functions

FindFoodAction(inst)

• Description: Determines the next food-related action for the pig: eat from inventory, take food from a shelf, or seek external food (meat only when hungry or饱食度 low). Skips if pig is busy ("busy" state tag), spectating a minigame, or recently ate.
• Parameters: inst — The pig entity instance.
• Returns: BufferedAction if a valid action exists; nil otherwise.
• Error states: Returns nil if inventory or eater component missing, no food found within range, or pig recently ate (time_since_eat <= TUNING.PIG_MIN_POOP_PERIOD * 2).

FindTreeToChopAction(inst)

• Description: Searches for a tree to chop if the pig is willing to help (e.g., leader is chopping or a deciduous tree monster is nearby). Prioritizes deciduous tree monsters (prefab == "deciduoustree") if nearby.
• Parameters: inst — The pig entity instance.
• Returns: BufferedAction targeting a tree with "CHOP_workable" tag; nil otherwise.
• Error states: Returns nil if no valid tree within SEE_TREE_DIST.

GoHomeAction(inst)

• Description: Initiates action to return to home if the pig has no leader, has a valid home, and is not currently in combat.
• Parameters: inst — The pig entity instance.
• Returns: BufferedAction with ACTIONS.GOHOME if criteria met; nil otherwise.
• Error states: Returns nil if no leader present, home invalid/destroyed/burning, or in combat.

FindDeciduousTreeMonster(inst)

• Description: Searches for a deciduous tree monster (prefab == "deciduoustree") within SEE_TREE_DIST / 3.
• Parameters: inst — The pig entity instance.
• Returns: Entity instance if found; nil otherwise.
• Error states: Returns nil if no such entity exists in range.

GetLeader(inst)

• Description: Returns the pig’s current leader from the follower component.
• Parameters: inst — The pig entity instance.
• Returns: Entity instance or nil.
• Error states: Returns nil if follower component missing or no leader assigned.

GetNoLeaderHomePos(inst)

• Description: Returns the home position only if the pig has no leader.
• Parameters: inst — The pig entity instance.
• Returns: Vector3 position or nil.
• Error states: Returns nil if leader exists or home invalid.

GetNearestLightPos(inst)

• Description: Finds the nearest light source within SEE_LIGHT_DIST and returns its world position.
• Parameters: inst — The pig entity instance.
• Returns: Vector3 position or nil.
• Error states: Returns nil if no light source found in range.

GetNearestLightRadius(inst)

• Description: Returns the calculated radius of the nearest light source within SEE_LIGHT_DIST.
• Parameters: inst — The pig entity instance.
• Returns: number (radius) or 1 if no light source found.
• Error states: Returns 1 if no light source found.

RescueLeaderAction(inst)

• Description: Attempts to unpig stuck leader using ACTIONS.UNPIN.
• Parameters: inst — The pig entity instance.
• Returns: BufferedAction or nil.
• Error states: Returns nil if leader missing, not stuck, or leader’s pinnable component absent.

WantsToGivePlayerPigTokenAction(inst)

• Description: Checks if pig wants to give its loyalty token to its leader (loyalty >= TUNING.PIG_FULL_LOYALTY_PERCENT and token in inventory).
• Parameters: inst — The pig entity instance.
• Returns: true or false.
• Error states: Returns false if leader missing, token not present, or loyalty below threshold.

GivePlayerPigTokenAction(inst)

• Description: Attempts to drop the loyalty token to the leader using ACTIONS.DROP.
• Parameters: inst — The pig entity instance.
• Returns: BufferedAction or nil.
• Error states: Returns nil if leader missing or token not found.

CurrentContestTarget(inst)

• Description: Returns the current target for NPC contestant pigs during a minigame contest.
• Parameters: inst — The pig entity instance.
• Returns: Entity or inst.npc_stage.
• Error states: Uses inst.npc_stage.current_contest_target if available.

GetTraderFn(inst)

• Description: Scans nearby players (within TRADE_DIST) and returns the first one attempting to trade.
• Parameters: inst — The pig entity instance.
• Returns: Player entity or nil.
• Error states: Returns nil if no trading player in range.

GetRunAwayTarget(inst)

• Description: Returns the pig’s current combat target as the target to run away from (e.g., during dodge behavior).
• Parameters: inst — The pig entity instance.
• Returns: Entity or nil.
• Error states: Returns nil if no combat target.

IsHomeOnFire(inst)

• Description: Checks if the pig’s home is burning and within a safe distance.
• Parameters: inst — The pig entity instance.
• Returns: true or false.
• Error states: Returns false if home missing, non-burning, too far, or burnt.

WatchingMinigame(inst)

• Description: Returns the minigame instance if the pig is spectating.
• Parameters: inst — The pig entity instance.
• Returns: Minigame entity or nil.
• Error states: Returns nil if minigame_spectator component missing or no minigame assigned.

Events & listeners

Pigbrain does not directly register or fire events. It interacts with the inst entity’s sg (stategraph) via inst.sg:HasStateTag("busy"), but this is part of the DoAction behavior wrapper, not event registration. The behavior tree is executed within the OnStart method and runs continuously via the BT behavior tree runner.