Moosebrain

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

Overview

This component implements the behavior tree for the moose entity in Don't Starve Together. It orchestrates high-level behaviors such as fleeing (shouldGoAway), leash tracking, chasing and attacking targets, laying eggs, facing nearby players, and wandering near a designated home location (landpoint). It inherits from Brain and constructs a BT (Behavior Tree) in OnStart() using priority-ordered behavior nodes defined in external behavior modules.

The moosebrain relies on several external components: Combat for target tracking, KnownLocations for home/landmark positions, and EntityTracker for locating related entities like eggs. It integrates with the behaviours module to delegate specific behavioral tasks (e.g., ChaseAndAttack, FaceEntity, Leash, Wander).

Dependencies & Tags

• Components used:
  • Combat (via self.inst.components.combat)
  • KnownLocations (via self.inst.components.knownlocations)
  • EntityTracker (via self.inst.components.entitytracker)
• Tags:
  • Checks: "notarget", "busy" (via inst:HasTag("notarget"), self.inst.sg:HasStateTag("busy"))
  • Sets: "busy" is only read (no tag modification logic present in this script)

Properties

Property	Type	Default Value	Description
inst.shouldGoAway	boolean	nil (checked dynamically)	Indicates whether the moose should flee/halt aggressive behavior and return home.
inst.WantsToLayEgg	boolean	nil (checked dynamically)	Controls whether the moose attempts to lay an egg.
inst.sg	StateGraph	—	The state graph instance; used to check busy state tag.
self.bt	BT	nil (assigned in OnStart)	The behavior tree constructed in OnStart().

Main Functions

GoHome(inst)

• Description: Returns a buffered ACTIONS.GOHOME action if the moose is in "go away" mode and has no active combat target; otherwise returns nil.
• Parameters: inst — the moose entity instance.
• Returns: BufferedAction (if conditions are met) or nil.

GetFaceTargetFn(inst)

• Description: Finds the closest player within START_FACE_DIST (15 units) that does not have the "notarget" tag, provided the moose is not currently in a "busy" state. Used by the FaceEntity behavior to select a new target to face.
• Parameters: inst — the moose entity instance.
• Returns: Entity (if found) or nil.

KeepFaceTargetFn(inst, target)

• Description: Determines whether to continue facing a given target. Returns true only if the moose is not in a "busy" state, does not have "notarget", and is within KEEP_FACE_DIST (20 units) of the target.
• Parameters:
  • inst — the moose entity instance.
  • target — the entity currently being faced.
• Returns: boolean.

LayEgg(inst)

• Description: Returns a buffered ACTIONS.LAYEGG action if the moose wishes to lay an egg and no egg entity has been registered yet via EntityTracker.
• Parameters: inst — the moose entity instance.
• Returns: BufferedAction (if conditions are met) or nil.

MooseBrain:OnStart()

• Description: Initializes the behavior tree with a priority-based root node that evaluates (in order):
  1. Flee if shouldGoAway is true (calls GoHome).
  2. Enforce leash distance (25 units) from the "landpoint" location.
  3. Chase and attack the current combat target.
  4. Attempt egg laying.
  5. Face a target (via GetFaceTargetFn and KeepFaceTargetFn).
  6. Wander within 15 units of "landpoint".
     The lowest-priority node is Wander. This function must be called by the game when the moose enters the world.
• Parameters: None.
• Returns: None.

MooseBrain:OnInitializationComplete()

• Description: Records the moose's initial position as "spawnpoint" in KnownLocations using RememberLocation. Ensures the spawn location is stored before gameplay proceeds.
• Parameters: None.
• Returns: None.

Events & Listeners

None.