BTPlayer

Inherits:

Player of BehaviorTree resources.

Description

BTPlayer node is used to instantiate and play BehaviorTree resources at runtime. During initialization, the behavior tree instance is given references to the agent, the blackboard, and the current scene root. The agent can be specified by the agent_node property (defaults to the BTPlayer’s parent node).

For an introduction to behavior trees, see BehaviorTree.

Properties

bool	active	`true`
NodePath	agent_node	`NodePath("..")`
BehaviorTree	behavior_tree
Blackboard	blackboard
BlackboardPlan	blackboard_plan
bool	monitor_performance	`false`
UpdateMode	update_mode	`1`

Methods

int	get_last_status ( ) const
BTTask	get_tree_instance ( )
void	restart ( )
void	update ( float delta )

Signals

behavior_tree_finished ( int status )

Emitted when the behavior tree has finished executing and returned SUCCESS or FAILURE.

Argument status holds the status returned by the behavior tree. See Status.

updated ( int status )

Emitted when BTPlayer has finished the behavior tree update.

Argument status holds the status returned by the behavior tree. See Status.

Enumerations

enum UpdateMode:

UpdateMode IDLE = 0

Execute behavior tree during the idle process.

UpdateMode PHYSICS = 1

Execute behavior tree during the physics process.

UpdateMode MANUAL = 2

Behavior tree is executed manually by calling update.

Property Descriptions

bool active = true

void set_active ( bool value )
bool get_active ( )

If true, the behavior tree will be executed during update.

NodePath agent_node = NodePath("..")

void set_agent_node ( NodePath value )
NodePath get_agent_node ( )

Path to the node that will be used as the agent. Setting it after instantiation will have no effect.

BehaviorTree behavior_tree

void set_behavior_tree ( BehaviorTree value )
BehaviorTree get_behavior_tree ( )

BehaviorTree resource to instantiate and execute at runtime.

Blackboard blackboard

void set_blackboard ( Blackboard value )
Blackboard get_blackboard ( )

Holds data shared by the behavior tree tasks. See Blackboard.

BlackboardPlan blackboard_plan

void set_blackboard_plan ( BlackboardPlan value )
BlackboardPlan get_blackboard_plan ( )

Stores and manages variables that will be used in constructing new Blackboard instances.

bool monitor_performance = false

If true, adds a performance monitor to “Debugger->Monitors” for each instance of this BTPlayer node.

UpdateMode update_mode = 1

void set_update_mode ( UpdateMode value )
UpdateMode get_update_mode ( )

Determines when the behavior tree is executed. See UpdateMode.

Method Descriptions

int get_last_status ( ) const

Returns the behavior tree’s last execution status. See Status.

BTTask get_tree_instance ( )

Returns the root task of the instantiated behavior tree.

void restart ( )

Resets the behavior tree’s execution. Each running task will be aborted and the next tree execution will start anew. This method does not reset Blackboard.

void update ( float delta )

Executes the root task of the behavior tree instance if active is true. Call this method when update_mode is set to MANUAL. When update_mode is not MANUAL, the update will be called automatically. See UpdateMode.