UE5 AnimNotify & Montage Tool Patterns

Role: Animation Tool Engineer Scope: Creating/modifying FAnimNotifyEvent in editor tools Engine: UE 5.5+

Critical Pattern: FAnimNotifyEvent Creation

When programmatically creating FAnimNotifyEvent entries for montages, you MUST follow the engine's expected initialization pattern. Missing any step causes editor bugs (selection issues, visual glitches, notify state backgrounds not rendering).

Required Steps

#include "Animation/AnimTypes.h"  // For GetTriggerTimeOffsetForType()

FAnimNotifyEvent NewEvent;

// 1. CRITICAL: Unique GUID for selection handling
NewEvent.Guid = FGuid::NewGuid();

// 2. Set the notify object (choose ONE)
// For instant notifies:
NewEvent.Notify = NewObject<UAnimNotify>(Montage, NotifyClass, NAME_None, RF_Transactional);
// OR for notify states:
NewEvent.NotifyStateClass = NewObject<UAnimNotifyState>(Montage, NotifyStateClass, NAME_None, RF_Transactional);
NewEvent.SetDuration(Duration);

// 3. Link to montage timeline
NewEvent.Link(Montage, StartTime);
NewEvent.TriggerTimeOffset = GetTriggerTimeOffsetForType(Montage->CalculateOffsetForNotify(StartTime));
NewEvent.TrackIndex = TrackIndex;

// 4. FOR NOTIFY STATES ONLY: Link the end time
if (NewEvent.NotifyStateClass)
{
    float EndTime = StartTime + Duration;
    NewEvent.EndLink.Link(Montage, EndTime);
    NewEvent.EndTriggerTimeOffset = GetTriggerTimeOffsetForType(Montage->CalculateOffsetForNotify(EndTime));
}

// 5. Add to montage
Montage->Notifies.Add(NewEvent);

// 6. Refresh after all notifies added
Montage->RefreshCacheData();

What Breaks Without Each Step

NotifyState Visual Rendering

Base UAnimNotifyState has no visual representation. For editor-visible notify states, create a concrete subclass:

UCLASS()
class UAnimNotifyState_MyCustom : public UAnimNotifyState
{
    GENERATED_BODY()
public:
    UAnimNotifyState_MyCustom()
    {
#if WITH_EDITORONLY_DATA
        NotifyColor = FColor(255, 216, 0, 255); // Yellow
#endif
    }

    virtual FLinearColor GetEditorColor() override
    {
        return FLinearColor(1.0f, 0.85f, 0.0f, 1.0f);
    }
};

Engine Reference

See Engine/Source/Editor/Persona/Private/SAnimNotifyPanel.cpp lines 2510-2579 for the canonical implementation.

Common Mistakes

1. Not setting unique GUIDs - Causes multi-selection bugs
2. Using base UAnimNotifyState - No background color in timeline
3. Forgetting EndLink for states - Duration handles don't work
4. Missing RefreshCacheData() - Notifies don't appear until save/reload
5. Wrong object outer - Use Montage as outer for notify objects

Legacy Metadata

skill: ue-anim-notify-patterns
invoke: /editor-tools:ue-anim-notify-patterns