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  3. UProjectileMovementComponent

UProjectileMovementComponent

ProjectileMovementComponent updates the position of another component during its tick.

API > API/Runtime > API/Runtime/Engine

ProjectileMovementComponent updates the position of another component during its tick.

Behavior such as bouncing after impacts and homing toward a target are supported.

Normally the root component of the owning actor is moved, however another component may be selected (see SetUpdatedComponent()). If the updated component is simulating physics, only the initial launch parameters (when initial velocity is non-zero) will affect the projectile, and the physics sim will take over from there.

   
Name UProjectileMovementComponent
Type class
Header File /Engine/Source/Runtime/Engine/Classes/GameFramework/ProjectileMovementComponent.h
Include Path #include "GameFramework/ProjectileMovementComponent.h"

Syntax

UCLASS (ClassGroup=Movement, Meta=(BlueprintSpawnableComponent), ShowCategories=(Velocity),  
       MinimalAPI)  
class UProjectileMovementComponent : public UMovementComponent

Inheritance Hierarchy

Implements Interfaces

Constructors

Name Remarks Include Path Unreal Specifiers

UProjectileMovementComponent ( const FObjectInitializer& ObjectInitializer
)

   GameFramework/ProjectileMovementComponent.h  

Classes

Name Remarks
FOnProjectileBounceDelegate  
FOnProjectileStopDelegate  

Enums

Protected

Name Remarks
EHandleBlockingHitResult Enum indicating how simulation should proceed after HandleBlockingHit() is called.

Constants

Name Type Remarks Include Path
MIN_TICK_TIME const float Minimum delta time considered when ticking. GameFramework/ProjectileMovementComponent.h

Variables

Public

Name Type Remarks Include Path Unreal Specifiers
bBounceAngleAffectsFriction uint8 Controls the effects of friction on velocity parallel to the impact surface when bouncing. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileBounces
bForceSubStepping uint8 If true, forces sub-stepping to break up movement into discrete smaller steps to improve accuracy of the trajectory. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileSimulation
bInitialVelocityInLocalSpace uint8 If true, the initial Velocity is interpreted as being in local space upon startup. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Projectile
bInterpMovement uint8 If true and there is an interpolated component set, location (and optionally rotation) interpolation is enabled which allows the interpolated object to smooth uneven updates of the UpdatedComponent's location (usually to smooth network updates). GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
bInterpolationUseScopedMovement uint8 If true, uses FScopedMovementUpdate to avoid moving the attached interpolated object's children more than once during a tick when it would both interpolate and move during projectile simulation. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • AdvancedDisplay
  • Category=ProjectileInterpolation
bInterpRotation uint8 If true and there is an interpolated component set, rotation interpolation is enabled which allows the interpolated object to smooth uneven updates of the UpdatedComponent's rotation (usually to smooth network updates). GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
bIsHomingProjectile uint8 If true, we will accelerate toward our homing target. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Homing
bIsSliding uint8 If true, projectile is sliding / rolling along a surface. GameFramework/ProjectileMovementComponent.h
  • VisibleInstanceOnly
  • BlueprintReadOnly
  • Category=ProjectileBounces
BounceAdditionalIterations int32 On the first few bounces (up to this amount), allow extra iterations over MaxSimulationIterations if necessary. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Meta=(ClampMin="0", ClampMax="4", UIMin="0", UIMax="4")
  • Category=ProjectileSimulation
BounceVelocityStopSimulatingThreshold float If velocity is below this threshold after a bounce, stops simulating and triggers the OnProjectileStop event. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileBounces
Bounciness float Percentage of velocity maintained after the bounce in the direction of the normal of impact (coefficient of restitution). GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileBounces
  • Meta=(ClampMin="0", UIMin="0")
bRotationFollowsVelocity uint8 If true, this projectile will have its rotation updated each frame to match the direction of its velocity. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Projectile
bRotationRemainsVertical uint8 If true, this projectile will have its rotation updated each frame to maintain the rotations Yaw only. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Projectile
  • Meta=(EditCondition="bRotationFollowsVelocity")
bShouldBounce uint8 If true, simple bounces will be simulated. Set this to false to stop simulating on contact. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileBounces
bSimulationEnabled uint8 If true, does normal simulation ticking and update. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileSimulation
bSimulationUseScopedMovement uint8 If true, uses FScopedMovementUpdate to avoid moving the UpdatedComponent more than once during a tick during simulation. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • AdvancedDisplay
  • Category=ProjectileInterpolation
bSweepCollision uint8 If true, movement uses swept collision checks. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileSimulation
bThrottleInterpolation uint8 If true, throttle interpolation when not relevant. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
Buoyancy float Buoyancy of UpdatedComponent in fluid. 0.0=sinks as fast as in air, 1.0=neutral buoyancy GameFramework/ProjectileMovementComponent.h  
Friction float Coefficient of friction, affecting the resistance to sliding along a surface. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileBounces
  • Meta=(ClampMin="0", UIMin="0")
HomingAccelerationMagnitude float The magnitude of our acceleration towards the homing target. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Homing
HomingTargetComponent TWeakObjectPtr< USceneComponent > The current target we are homing towards. GameFramework/ProjectileMovementComponent.h
  • VisibleInstanceOnly
  • BlueprintReadWrite
  • Category=Homing
InitialSpeed float Initial speed of projectile. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Projectile
InterpLocationMaxLagDistance float Max distance behind UpdatedComponent which the interpolated component is allowed to lag. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
  • Meta=(ClampMin="0")
InterpLocationSnapToTargetDistance float Max distance behind UpdatedComponent beyond which the interpolated component is snapped to the target location instead. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
  • Meta=(ClampMin="0")
InterpLocationTime float "Time" over which most of the location interpolation occurs, when the UpdatedComponent (target) moves ahead of the interpolated component. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
  • Meta=(ClampMin="0")
InterpRotationTime float "Time" over which most of the rotation interpolation occurs, when the UpdatedComponent (target) moves ahead of the interpolated component. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
  • Meta=(ClampMin="0")
MaxSimulationIterations int32 Max number of iterations used for each discrete simulation step. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Meta=(ClampMin="1", ClampMax="25", UIMin="1", UIMax="25")
  • Category=ProjectileSimulation
MaxSimulationTimeStep float Max time delta for each discrete simulation step. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Meta=(ClampMin="0.0166", ClampMax="0.50", UIMin="0.0166", UIMax="0.50")
  • Category=ProjectileSimulation
MaxSpeed float Limit on speed of projectile (0 means no limit). GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Projectile
MinFrictionFraction float When bounce angle affects friction, apply at least this fraction of normal friction. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileBounces
  • AdvancedDisplay
  • Meta=(ClampMin="0", UIMin="0", ClampMax="1", UIMax="1")
OnProjectileBounce FOnProjectileBounceDelegate Called when projectile impacts something and bounces are enabled. GameFramework/ProjectileMovementComponent.h
  • BlueprintAssignable
OnProjectileStop FOnProjectileStopDelegate Called when projectile has come to a stop (velocity is below simulation threshold, bounces are disabled, or it is forcibly stopped). GameFramework/ProjectileMovementComponent.h
  • BlueprintAssignable
PreviousHitNormal FVector Saved HitResult Normal from previous simulation step that resulted in an impact. GameFramework/ProjectileMovementComponent.h
  • VisibleInstanceOnly
  • BlueprintReadOnly
  • Category=ProjectileBounces
PreviousHitTime float Saved HitResult Time (0 to 1) from previous simulation step. Equal to 1.0 when there was no impact. GameFramework/ProjectileMovementComponent.h
  • VisibleInstanceOnly
  • BlueprintReadOnly
  • Category=ProjectileBounces
ProjectileGravityScale float Custom gravity scale for this projectile. Set to 0 for no gravity. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Projectile
ThrottleInterpolationSkipFramesNotRecent int32 When not recently relevant, skip this many frames of interpolation if throttling is enabled. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
  • AdvancedDisplay
  • Meta=(ClampMin="0", UIMin="0")
ThrottleInterpolationSkipFramesRecent int32 When recently relevant, skip this many frames of interpolation if throttling is enabled. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
  • AdvancedDisplay
  • Meta=(ClampMin="0", UIMin="0")
ThrottleInterpolationThresholdNotRenderedLongTime float Time after not rendered for a long time when we consider throttling interpolation. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
  • AdvancedDisplay
ThrottleInterpolationThresholdNotRenderedShortTime float Time after not rendered recently when we consider throttling interpolation. GameFramework/ProjectileMovementComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=ProjectileInterpolation
  • AdvancedDisplay

Protected

Name Type Remarks Include Path Unreal Specifiers
PendingForce FVector Pending force for next tick. GameFramework/ProjectileMovementComponent.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

void AddForce ( FVector Force
)

 Adds a force which is accumulated until next tick, used by ComputeAcceleration() to affect Velocity. GameFramework/ProjectileMovementComponent.h  

virtual bool CheckStillInWorld ()

 This will check to see if the projectile is still in the world. GameFramework/ProjectileMovementComponent.h  

void ClearPendingForce ( bool bClearImmediateForce
)

 Clears any pending forces from AddForce(). GameFramework/ProjectileMovementComponent.h  

virtual FVector ComputeAcceleration ( const FVector& InVelocity,
float DeltaTime
) const

 Compute the acceleration that will be applied GameFramework/ProjectileMovementComponent.h  

virtual FVector ComputeHomingAcceleration ( const FVector& InVelocity,
float DeltaTime
) const

 Allow the projectile to track towards its homing target. GameFramework/ProjectileMovementComponent.h  

virtual FVector ComputeMoveDelta ( const FVector& InVelocity,
float DeltaTime
) const

 Compute the distance we should move in the given time, at a given a velocity. GameFramework/ProjectileMovementComponent.h  

virtual FVector ComputeVelocity ( FVector InitialVelocity,
float DeltaTime
) const

 Given an initial velocity and a time step, compute a new velocity. GameFramework/ProjectileMovementComponent.h  

float GetBuoyancy()

   GameFramework/ProjectileMovementComponent.h  

USceneComponent * GetInterpolatedComponent()

 Returns the component used for network interpolation. GameFramework/ProjectileMovementComponent.h  

FVector GetPendingForce()

 Returns the sum of pending forces from AddForce(). GameFramework/ProjectileMovementComponent.h  

float GetSimulationTimeStep ( float RemainingTime,
int32 Iterations
) const

 Compute remaining time step given remaining time and current iterations. GameFramework/ProjectileMovementComponent.h  

bool HasStoppedSimulation()

   GameFramework/ProjectileMovementComponent.h  
Returns whether interpolation is complete because the target has been reached. GameFramework/ProjectileMovementComponent.h
  • BlueprintCallable
  • Category="Game|Components|ProjectileMovement|Interpolation"

bool IsVelocityUnderSimulationThreshold()

 Returns true if velocity magnitude is less than BounceVelocityStopSimulatingThreshold. GameFramework/ProjectileMovementComponent.h
  • BlueprintCallable
  • Category="Game|Components|ProjectileMovement"

FVector LimitVelocity ( FVector NewVelocity
) const

 Don't allow velocity magnitude to exceed MaxSpeed, if MaxSpeed is non-zero. GameFramework/ProjectileMovementComponent.h
  • BlueprintCallable
  • Category="Game|Components|ProjectileMovement"

virtual void MoveInterpolationTarget ( const FVector& NewLocation,
const FRotator& NewRotation
)

 Moves the UpdatedComponent, which is also the interpolation target for the interpolated component. GameFramework/ProjectileMovementComponent.h
  • BlueprintCallable
  • Category="Game|Components|ProjectileMovement|Interpolation"

virtual void ResetInterpolation()

 Resets interpolation so that interpolated component snaps back to the initial location/rotation without any additional offsets. GameFramework/ProjectileMovementComponent.h
  • BlueprintCallable
  • Category="Game|Components|ProjectileMovement|Interpolation"

virtual void SetInterpolatedComponent ( USceneComponent* Component
)

 Assigns the component that will be used for network interpolation/smoothing. GameFramework/ProjectileMovementComponent.h
  • BlueprintCallable
  • Category="Game|Components|ProjectileMovement|Interpolation"

virtual void SetVelocityInLocalSpace ( FVector NewVelocity
)

 Sets the velocity to the new value, rotated into Actor space. GameFramework/ProjectileMovementComponent.h
  • BlueprintCallable
  • Category="Game|Components|ProjectileMovement"

bool ShouldApplyGravity()

   GameFramework/ProjectileMovementComponent.h  

virtual bool ShouldUseSubStepping ()

 Determine whether or not to use substepping in the projectile motion update. GameFramework/ProjectileMovementComponent.h  

virtual void StopSimulating ( const FHitResult& HitResult
)

 Clears the reference to UpdatedComponent, fires stop event (OnProjectileStop), and stops ticking (if bAutoUpdateTickRegistration is true). GameFramework/ProjectileMovementComponent.h
  • BlueprintCallable
  • Category="Game|Components|ProjectileMovement"

Overridden from UMovementComponent

Name Remarks Include Path Unreal Specifiers

virtual float GetGravityZ()

 Compute gravity effect given current physics volume, projectile gravity scale, etc. GameFramework/ProjectileMovementComponent.h  

virtual float GetMaxSpeed()

 Returns maximum speed of component in current movement mode. GameFramework/ProjectileMovementComponent.h  

virtual void UpdateTickRegistration ()

 Update tick registration state, determined by bAutoUpdateTickRegistration. GameFramework/ProjectileMovementComponent.h  

Overridden from UActorComponent

Name Remarks Include Path Unreal Specifiers

virtual void InitializeComponent()

 Overridden to auto-register the updated component if it starts NULL, and we can find a root component on our owner. GameFramework/ProjectileMovementComponent.h  

virtual void TickComponent ( float DeltaTime,
enum ELevelTick TickType,
FActorComponentTickFunction* ThisTickFunction
)

 Function called every frame on this ActorComponent. GameFramework/ProjectileMovementComponent.h  

Overridden from UObject

Name Remarks Include Path Unreal Specifiers

virtual void PostLoad()

   GameFramework/ProjectileMovementComponent.h  

Protected

Name Remarks Include Path Unreal Specifiers

virtual FVector ComputeBounceResult ( const FHitResult& Hit,
float TimeSlice,
const FVector& MoveDelta
)

 Computes result of a bounce and returns the new velocity. GameFramework/ProjectileMovementComponent.h  

virtual int32 ComputeThrottleInterpolationMaxFrames ( float DeltaTime,
USceneComponent* InterpComponent
)

 Determine the number of frames to allow to skip when interpolating. GameFramework/ProjectileMovementComponent.h  

virtual EHandleBlockingHitResult HandleBlockingHit ( const FHitResult& Hit,
float TimeTick,
const FVector& MoveDelta,
float& SubTickTimeRemaining
)

 Handle blocking hit during simulation update. GameFramework/ProjectileMovementComponent.h  

virtual bool HandleDeflection ( FHitResult& Hit,
const FVector& OldVelocity,
const uint32 NumBounces,
float& SubTickTimeRemaining
)

 Handle a blocking hit after HandleBlockingHit() returns a result indicating that deflection occured. GameFramework/ProjectileMovementComponent.h  

virtual bool HandleSliding ( FHitResult& Hit,
float& SubTickTimeRemaining
)

 Handle case where projectile is sliding along a surface. GameFramework/ProjectileMovementComponent.h  

virtual void ResetThrottleInterpolation ( float DeltaTime
)

 Custom hook to reset throttle interpolation tracking when it was throttling previously. GameFramework/ProjectileMovementComponent.h  

virtual void TickInterpolation ( float DeltaTime
)

   GameFramework/ProjectileMovementComponent.h  

bool UpdateThrottleInterpolation ( float DeltaTime,
USceneComponent* InterpComponent
)

 Update interpolation throttling for this frame. GameFramework/ProjectileMovementComponent.h  

Overridden from UMovementComponent

Name Remarks Include Path Unreal Specifiers

virtual void HandleImpact ( const FHitResult& Hit,
float TimeSlice,
const FVector& MoveDelta
)

 Applies bounce logic if enabled to affect velocity upon impact (using ComputeBounceResult()), or stops the projectile if bounces are not enabled or velocity is below BounceVelocityStopSimulatingThreshold. GameFramework/ProjectileMovementComponent.h  

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