Rockybrain

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

Overview

rockybrain is the brain component for the Beefalo entity Rocky. It orchestrates high-level decision-making using a Behavior Tree (BT) to coordinate responses to combat, leadership, hunger, and environmental stimuli. Key responsibilities include:

• Executing shield-based defense in response to incoming damage and projectile attacks.
• Losing loyalty with a probability when scared, potentially abandoning the leader.
• Tracking and following a leader while maintaining optimal distance.
• Wandering toward the known "herd" location.
• Prioritizing combat engagement, eating, and entity facing behavior.

The brain relies heavily on external behavior modules (e.g., chaseandattack, useshield, wander) and integrates with components like combat, follower, eater, inventory, and knownlocations.

Usage example

local inst = CreateEntity()
inst:AddComponent("rockybrain")
-- Rockybrain is a brain component and is automatically initialized on start/stop by the brain system.
-- Typical brain activation occurs via inst:PushEvent("becomeplayer") or similar state changes.

Dependencies & tags

Components used:

• combat: calls SetTarget, checks for ally status.
• eater: calls CanEat to assess edible items.
• follower: calls GetLeader, GetLoyaltyPercent, SetLeader.
• inventory: calls FindItem to locate edible items in inventory.
• inventoryitem: checks canbepickedup for potential food items.
• knownlocations: calls GetLocation("herd") to determine wander destination.

Tags: None directly added or removed by this brain itself.

Properties

Property	Type	Default Value	Description
scareendtime	number	0 (initial)	Timestamp indicating when the current scare period ends; updated on "epicscare" events.
scaredelay	number or nil	nil	Delay timer used to space loyalty loss checks after a scare event.
onepicscarefn	function or nil	nil	Event callback registered to "epicscare" that extends scareendtime.
bt	BehaviorTree	nil	Behavior tree instance created in OnStart and used to drive decision making.

Main functions

RockyBrain:OnStart()

• Description: Initializes the brain's Behavior Tree when the entity becomes active. Registers a listener for "epicscare" events and builds a priority-based behavior tree composed of multiple behavior nodes.
• Parameters: None.
• Returns: Nothing.
• Error states: None. Uses defensive checks to avoid duplicate registration of the "epicscare" callback.

RockyBrain:OnStop()

• Description: Cleans up the "epicscare" event listener and associated state (scareendtime, onepicscarefn) when the brain is deactivated.
• Parameters: None.
• Returns: Nothing.
• Error states: None.

GetFaceTargetFn(inst)

• Description: Returns the closest player within START_FACE_DIST (4 units) who is not tagged "notarget". Used by FaceEntity behavior to determine which entity to face.
• Parameters:
  • inst: The entity instance whose brain is requesting the face target.
• Returns: TheTarget (entity) or nil.
• Error states: Returns nil if no valid target is found or if the closest target is tagged "notarget".

KeepFaceTargetFn(inst, target)

• Description: Determines whether the entity should continue facing a given target based on proximity (KEEP_FACE_DIST, 6 units) and absence of the "notarget" tag.
• Parameters:
  • inst: The entity instance.
  • target: The target entity to evaluate.
• Returns: true if still facing should be maintained; otherwise false.
• Error states: Returns false if target has "notarget" or exceeds KEEP_FACE_DIST.

CanPickup(item)

• Description: Utility function that checks whether an item can be picked up. Ensures the item is pickable, sufficiently aged (at least 8 seconds old), and on valid ground.
• Parameters:
  • item: The entity to evaluate for pickup eligibility.
• Returns: true if the item is eligible for pickup; otherwise false.
• Error states: None.

EatFoodAction(inst)

• Description: Constructs a buffered action for Rocky to either eat food from its inventory or pick up an edible item from the world if inventory is empty. Prioritizes existing inventory consumption before searching externally.
• Parameters:
  • inst: The entity instance.
• Returns: BufferedAction or nil.
• Error states: Returns nil if:
  • The stategraph has the "busy" tag.
  • No food is in inventory (if inventory/eater components exist).
  • No eligible edible item is found within range (15 units) matching EATFOOD_MUST_TAGS and not in EATFOOD_CANT_TAGS.

ScaredLoseLoyalty(self)

• Description: Checks whether Rocky should lose loyalty (i.e., lose its leader) after being scared. Only evaluates the loyalty loss chance after a delay (3 seconds) from the last scare event. Uses TryLuckRoll with LuckFormulas.LoseFollowerOnPanic to determine outcome.
• Parameters:
  • self: The brain object (passed implicitly in Behavior Tree context).
• Returns: Nothing.
• Error states: Does not error, but may fail silently if:
  • follower component is missing.
  • Leader is nil.
  • Loyalty is already 0.
  • Luck roll fails.

Events & listeners

• Listens to: "epicscare" — Triggers self.onepicscarefn, which updates scareendtime to extend the scare duration window.
• Pushes: None. Events like "leaderchanged" are pushed internally by the follower component (not this brain), and this brain responds to them via component callbacks.

---