AAIController::SuggestTossVelocity

function AIModule Since 4.0

#include "AIController.h"

Access: public

Description

Computes a launch velocity that will arc a projectile from Start to End under gravity at the given speed. Returns false if no valid trajectory exists (target out of range or obstructed).

Caveats & Gotchas

• Potentially expensive — it runs physics traces along the arc. CollisionRadius > 0 combined with bOnlyTraceUp = false is the worst-case path; throttle call frequency or cache results for high-frequency AI shooters.
• Assumes the projectile is affected only by gravity after launch — no drag, no homing, no custom forces. If your projectile uses a custom movement component, the computed velocity will be wrong.
• Returns false when the horizontal distance exceeds what TossSpeed can reach under the current world gravity. OutTossVelocity is left unchanged on failure; the caller must check the return value before applying the velocity.

Signature

bool SuggestTossVelocity(FVector& OutTossVelocity, FVector Start, FVector End, float TossSpeed, bool bPreferHighArc, float CollisionRadius = 0, bool bOnlyTraceUp = false)

Parameters

Name	Type	Description	Default
OutTossVelocity	FVector&	Output: the computed initial velocity to apply to the projectile.	—
Start	FVector	World-space launch origin of the arc.	—
End	FVector	World-space target point of the arc.	—
TossSpeed	float	Initial launch speed of the projectile in cm/s.	—
bPreferHighArc	bool	When two solutions exist, prefer the higher arc trajectory.	—
CollisionRadius	float	Bounding radius of the projectile for clearance checks; 0 for point traces.	0
bOnlyTraceUp	bool	When true, collision checks are only performed on the ascending portion of the arc.	false

Return Type

bool

Example

Compute and apply a grenade toss velocity C++

FVector LaunchVelocity;
APawn* MyPawn = GetPawn();
if (!MyPawn) return;
FVector MuzzleLocation = MyPawn->GetActorLocation() + FVector(0, 0, 50.f);
if (SuggestTossVelocity(LaunchVelocity, MuzzleLocation, TargetLocation, 1200.f, /*bPreferHighArc=*/false))
{
	AGrenade* Grenade = GetWorld()->SpawnActor<AGrenade>(GrenadeClass, MuzzleLocation, FRotator::ZeroRotator);
	if (Grenade)
	{
		Grenade->GetProjectileMovement()->Velocity = LaunchVelocity;
	}
}

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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