UAnimInstance::RequestTransitionEvent

function Engine Blueprint Since 5.3

#include "Animation/AnimInstance.h"

Access: public Specifiers: ENGINE_APIUFUNCTIONBlueprintCallable

Description

Queues a named transition event on the animation state machine. Returns true if the request was successfully queued. Complements the `QueryTransitionEvent` AnimGetter used inside transition rules.

Caveats & Gotchas

• The event must be consumed via `QueryTransitionEvent` (an AnimGetter node) inside a transition rule condition within the state machine — if no transition rule checks for it, the request silently expires after `RequestTimeout` seconds.
• Marked BlueprintThreadSafe so it can be called from the worker thread during the parallel update, but the underlying queue uses a mutex; avoid calling it at very high frequency every frame to minimise contention.

Signature

UFUNCTION(BlueprintCallable, Category="Animation", meta = (BlueprintThreadSafe, Keywords = "Event,Request,Transition"))
ENGINE_API bool RequestTransitionEvent(const FName EventName, const double RequestTimeout, const ETransitionRequestQueueMode QueueMode, const ETransitionRequestOverwriteMode OverwriteMode)

Parameters

Name	Type	Description	Default
EventName	const FName	The name of the transition event to request, matching the event name used in the state machine transition rules.	—
RequestTimeout	const double	How long in seconds the request remains valid before it expires.	—
QueueMode	const ETransitionRequestQueueMode	Whether requests accumulate in a queue or replace each other.	—
OverwriteMode	const ETransitionRequestOverwriteMode	How an existing request with the same name is handled when a new one arrives.	—

Return Type

bool

Example

Request a jump transition from game code C++

AnimInstance->RequestTransitionEvent(
    FName("Jump"),
    0.2,  // expire after 200ms if not consumed
    ETransitionRequestQueueMode::Overwrite,
    ETransitionRequestOverwriteMode::UseMostRecent
);

Version History

Introduced in: 5.3

Version	Status	Notes
5.6	stable	—
5.3	stable	Added in 5.3.

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