UGameplayStatics::Blueprint_PredictProjectilePath_ByObjectType

function Engine Blueprint Since 4.15

#include "Kismet/GameplayStatics.h"

Access: public Specifiers: staticBlueprintCallable

Description

Simulates a projectile arc under gravity and returns the full path as an array of positions, optionally tracing against specified object types to detect collisions. Returns true if the simulated projectile hit something.

Caveats & Gotchas

• SimFrequency and MaxSimTime directly trade accuracy for performance — high SimFrequency with long MaxSimTime can be expensive when called every frame; cache results and re-run only when inputs change.
• OutPathPositions is cleared and repopulated on every call; pre-allocating the array externally has no effect on allocation behaviour.
• When bTracePath is false the function still returns path positions but always returns false, even if the arc passes through geometry.

Signature

static ENGINE_API bool Blueprint_PredictProjectilePath_ByObjectType(const UObject* WorldContextObject, FHitResult& OutHit, TArray<FVector>& OutPathPositions, FVector& OutLastTraceDestination, FVector StartPos, FVector LaunchVelocity, bool bTracePath, float ProjectileRadius, const TArray<TEnumAsByte<EObjectTypeQuery> >& ObjectTypes, bool bTraceComplex, const TArray<AActor*>& ActorsToIgnore, EDrawDebugTrace::Type DrawDebugType, float DrawDebugTime, float SimFrequency = 15.f, float MaxSimTime = 2.f, float OverrideGravityZ = 0);

Parameters

Name	Type	Description	Default
WorldContextObject	const UObject*	Any UObject within the world to provide world context.	—
OutHit	FHitResult&	Output: hit result if the simulated projectile hits something.	—
OutPathPositions	TArray<FVector>&	Output: ordered positions of the simulated arc from StartPos to end.	—
OutLastTraceDestination	FVector&	Output: goal position of the final trace step (not in path if a hit occurred).	—
StartPos	FVector	Starting position of the projectile.	—
LaunchVelocity	FVector	Initial velocity of the simulated projectile.	—
bTracePath	bool	If true, traces along the arc to detect blocking hits against the specified object types.	—
ProjectileRadius	float	Radius of the simulated spherical projectile.	—
ObjectTypes	const TArray<TEnumAsByte<EObjectTypeQuery>>&	Object types to trace against.	—
bTraceComplex	bool	Whether to trace against complex collision geometry.	—
ActorsToIgnore	const TArray<AActor*>&	Actors to exclude from collision checks.	—
DrawDebugType	EDrawDebugTrace::Type	Controls debug visualization (none, one-frame, duration, persistent).	—
DrawDebugTime	float	Duration in seconds for debug lines when using the Duration draw type.	—
SimFrequency	float	Number of simulation steps per second; higher values give more accurate paths at greater cost.	15.f
MaxSimTime	float	Maximum simulation time in seconds.	2.f
OverrideGravityZ	float	Optional gravity override; 0 uses world gravity.	0

Return Type

bool

Example

Predict grenade arc against world static objects C++

FHitResult HitResult;
TArray<FVector> PathPositions;
FVector LastDest;
TArray<TEnumAsByte<EObjectTypeQuery>> ObjectTypes = { UEngineTypes::ConvertToObjectType(ECC_WorldStatic) };
TArray<AActor*> Ignored = { this };

bool bHit = UGameplayStatics::Blueprint_PredictProjectilePath_ByObjectType(
    this, HitResult, PathPositions, LastDest,
    GetActorLocation(), LaunchVelocity,
    true, 10.f, ObjectTypes, false, Ignored,
    EDrawDebugTrace::ForDuration, 1.f
);

Version History

Introduced in: 4.15

Version	Status	Notes
5.6	stable	—

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