ACharacter::ApplyDamageMomentum

function Engine Since 4.0

#include "GameFramework/Character.h"

Access: public Specifiers: virtual

Description

Applies an impulse to the character's movement component based on the incoming damage event. Typically called from TakeDamage() to produce a physics-style knockback effect.

Caveats & Gotchas

• This does nothing by default — the base implementation is empty. You must override it and call LaunchCharacter() or AddImpulse() yourself to get actual knockback behaviour.
• The magnitude of the impulse is not tied to DamageTaken automatically; you decide the relationship in your override. Common mistake is assuming it self-scales.

Signature

virtual void ApplyDamageMomentum(float DamageTaken, FDamageEvent const& DamageEvent, APawn* PawnInstigator, AActor* DamageCauser)

Parameters

Name	Type	Description	Default
DamageTaken	float	Amount of damage that was applied.	—
DamageEvent	FDamageEvent const&	The damage event describing the hit, including hit result and damage type.	—
PawnInstigator	APawn*	The pawn that caused the damage.	—
DamageCauser	AActor*	The actor that directly caused the damage (e.g. a projectile).	—

Return Type

void

Example

Apply knockback from point damage C++

void AMyCharacter::ApplyDamageMomentum(float DamageTaken, FDamageEvent const& DamageEvent,
    APawn* PawnInstigator, AActor* DamageCauser)
{
    const UDamageType* DmgType = DamageEvent.DamageTypeClass
        ? DamageEvent.DamageTypeClass->GetDefaultObject<UDamageType>()
        : GetDefault<UDamageType>();

    if (GetCharacterMovement() && DmgType->DamageImpulse > 0.f)
    {
        FHitResult HitInfo;
        FVector ImpulseDir;
        DamageEvent.GetBestHitInfo(this, DamageCauser, HitInfo, ImpulseDir);
        FVector Impulse = ImpulseDir * DmgType->DamageImpulse;
        LaunchCharacter(Impulse, false, false);
    }
}

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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