UBehaviorTreeComponent::IsInstanceStackEmpty

function AIModule Since 4.0

#include "BehaviorTree/BehaviorTreeComponent.h"

Access: public Specifiers: const

Description

Returns true if the instance stack has no running behavior tree instances — no tree has been started, or the tree has fully stopped and been cleaned up.

Caveats & Gotchas

• A paused tree (PauseLogic) still has instances on the stack, so this returns false while paused — use IsRunning/IsPaused if you need to distinguish paused from stopped.
• It's a plain inline check on InstanceStack.Num(), so it's cheap to call every frame if needed.

Signature

bool IsInstanceStackEmpty() const

Return Type

bool

Example

Guarding against acting on a stopped tree C++

if (!BTComponent->IsInstanceStackEmpty())
{
    BTComponent->RequestBranchEvaluation(EBTNodeResult::Succeeded);
}

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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