limboai/doc/source/behavior-trees/accessing-nodes.rst

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.. _accessing_nodes:
Accessing nodes in the scene tree
=================================
There are several ways to access nodes in the agent's scene tree from a :ref:`BTTask<class_BTTask>`.
**🛈 Note:** The root node of the agent's scene tree can be accessed with the
:ref:`scene_root<class_BTTask_property_scene_root>` property.
With ``BBNode`` property
------------------------
.. code:: gdscript
@export var cast_param: BBNode
func _tick(delta) -> Status:
var node: ShapeCast3D = cast_param.get_value(scene_root, blackboard)
With ``NodePath`` property
--------------------------
.. code:: gdscript
@export var cast_path: NodePath
func _tick(delta) -> Status:
var node: ShapeCast3D = scene_root.get_node(cast_path)
Using blackboard plan
---------------------
You can :ref:`create a blackboard variable<editing_plan>` in the editor with the type ``NodePath``
and point it to the proper node in the :ref:`BTPlayer<class_BTPlayer>` blackboard plan. By default,
any ``NodePath`` variable will be replaced with the node instance when the blackboard is instantiated
at runtime (see :ref:`BlackboardPlan.prefetch_nodepath_vars<class_BlackboardPlan_property_prefetch_nodepath_vars>`).
.. code:: gdscript
extends BTCondition
@export var shape_var: StringName = &"shape_cast"
func _tick(delta) -> Status:
var shape_cast: ShapeCast3D = blackboard.get_var(shape_var)
The property :ref:`BTPlayer.prefetch_nodepath_vars<class_BTPlayer_property_prefetch_nodepath_vars>` should be set to ``true``.