UBTService_ReadAttributeValue

Overview

UBTService_ReadAttributeValue is a Behavior Tree service designed to read an attribute's value from a ULimenAttributeBase object and store it in the blackboard under a specified key. It supports different methods for reading the attribute value, such as literal, fraction, or percentage.

Properties

Type	Name	Access	Description
FBlackboardKeySelector	AttributeInstanceKey	EditAnywhere	The key to select the attribute instance from the blackboard.
FBlackboardKeySelector	KeyToStoreValue	EditAnywhere	The key under which the attribute value will be stored in the blackboard.
EReadAttributeMethod	ReadValueMethod	EditAnywhere	The method used to read the attribute value (Literal, Fraction, Percentage).

Functions

Return Type	Signature	Description
void	InitializeFromAsset(UBehaviorTree& Asset)	Initializes the service from a behavior tree asset. Resolves the selected keys for `AttributeInstanceKey` and `KeyToStoreValue`.
void	OnBecomeRelevant(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory)	Called when the node becomes relevant. Currently does nothing.
void	TickNode(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory, float DeltaSeconds)	Ticks the node and reads the attribute value based on `ReadValueMethod`, then stores it in the blackboard under `KeyToStoreValue`.

Usage & Implementation Notes

Threading Constraints: This service is designed to run within the Behavior Tree system and does not have specific threading constraints.
Replication Requirements: No replication is required for this service as it operates on local data.
Memory Lifetime Management: The service does not manage any dynamic memory that requires special handling.
Initialization Dependencies: The AttributeInstanceKey and KeyToStoreValue must be set in the Behavior Tree editor before using this service.

22 May 2026