UBlackboardComponent::SetValueAsFloat
#include "BehaviorTree/BlackboardComponent.h"
Access: public
Specifiers: UFUNCTIONBlueprintCallable
Description
Writes a float value to a blackboard key, which can then be read by behavior tree tasks and decorators. Commonly used to store alert levels, distances, counters, and other scalar AI state.
Signature
void SetValueAsFloat(const FName& KeyName, float FloatValue)Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| KeyName | const FName& | The name of the float blackboard key to write. | — |
| FloatValue | float | The value to store. | — |
Return Type
void Caveats & Gotchas
- • Silently does nothing if the key doesn't exist in the BlackboardData asset.
- • Writing a float to a key declared with a different type in the BlackboardData asset is silently ignored. Type mismatches are not logged in non-debug builds.
- • Changes are visible to behavior tree nodes immediately — if a decorator is observing this key, the tree may be interrupted and re-evaluated on the next tick after the write.
Example
Update an alert level C++
// In an AI perception handler
BlackboardComp->SetValueAsFloat(TEXT("AlertLevel"), NewAlertLevel);Tags
Version History
Introduced in: 4.0
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
Feedback
Was this helpful?