1. Epic GamesDeveloper
  3. UPathFollowingComponent

UPathFollowingComponent

API > API/Runtime > API/Runtime/AIModule > API/Runtime/AIModule/Navigation

Inheritance Hierarchy

References

   
Module AIModule
Header /Engine/Source/Runtime/AIModule/Classes/Navigation/PathFollowingComponent.h
Include #include "Navigation/PathFollowingComponent.h"

Syntax

class UPathFollowingComponent :  
    public UActorComponent,  
    public IAIResourceInterface,  
    public IPathFollowingAgentInterface

Variables

  Type Name Description
Protected variable float AcceptanceRadius Min distance to destination to consider request successful.
Protected variable uint8: 1 bCollidedWithGoal Set when agent collides with goal actor
Protected variable uint8: 1 bIsDecelerating True if pathfollowing is doing deceleration at the end of the path.
Protected variable uint8: 1 bIsUsingMetaPath If set, path following is using FMetaNavMeshPath
Protected variable uint8: 1 bLastMoveReachedGoal Set when last move request was finished at goal
Protected variable float BlockDetectionDistance Detect blocked movement when distance between center of location samples and furthest one (centroid radius) is below threshold
Protected variable float BlockDetectionInterval Interval for collecting location samples
Protected variable int32 BlockDetectionSampleCount Number of samples required for block detection
Protected variable uint8: 1 bMoveToGoalOnLastSegment If set, target location will be constantly updated to match goal actor while following last segment of full path
Protected variable uint8: 1 bReachTestIncludesAgentRadius Increase acceptance radius with agent's radius
Protected variable uint8: 1 bReachTestIncludesGoalRadius Increase acceptance radius with goal's radius
Protected variable uint8: 1 bStopMovementOnFinish If set, movement will be stopped on finishing path
Protected variable uint8: 1 bUseBlockDetection If set, movement block detection will be used
Protected variable uint8: 1 bWalkingNavLinkStart Gets set when agent starts following a navigation link.
Protected variable float CachedBrakingDistance Braking distance for acceleration driven path following
Protected variable float CachedBrakingMaxSpeed Max speed used for CachedBrakingDistance
Protected variable float CurrentAcceptanceRadius Min distance to end of current path segment to consider segment finished
Protected variable FWeakObjectPtr CurrentCustomLinkOb Currently traversed custom nav link
Protected variable FBasedPosition CurrentDestination Destination for current path segment
Protected variable FVector CurrentMoveInput Last MoveInput calculated and passed over to MovementComponent.
Public variable uint8: 1 DEBUG_bMovingDirectlyToGoal  
Protected variable int32 DecelerationSegmentIndex Index of path point for starting deceleration
Protected variable TWeakObjectPtr< AActor > DestinationActor Destination actor. Use SetDestinationActor to set this
Protected variable const INavAgentInterface * DestinationAgent Cached DestinationActor cast to INavAgentInterface.
Protected variable FCustomMoveSharedPtr GameData Game specific data
Protected variable double LastSampleTime Timestamp of last location sample
Protected variable TArray< FBasedPosition > LocationSamples Location samples for stuck detection
Protected variable FVector LocationWhenPaused Agent location when movement was paused
Protected variable float MinAgentHalfHeightPct Part of agent height used as min acceptable height difference
Protected variable float MinAgentRadiusPct Part of agent radius used as min acceptance radius
Protected variable TObjectPtr< UNavMovementComponent > MovementComp Associated movement component
Protected variable FVector MoveOffset Relative offset from goal actor's location to end of path
Protected variable FVector MoveSegmentDirection Direction of current move segment
Protected variable int32 MoveSegmentEndIndex Index of path point being current move target
Protected variable NavNodeRef MoveSegmentEndRef Reference of node at segment end
Protected variable int32 MoveSegmentStartIndex Index of path point being current move beginning
Protected variable NavNodeRef MoveSegmentStartRef Reference of node at segment start
Protected variable float MyDefaultAcceptanceRadius Value based on navigation agent's properties that's used for AcceptanceRadius when DefaultAcceptanceRadius is requested
Protected variable TObjectPtr< ANavigationData > MyNavData Navigation data for agent described in movement component
Protected variable int32 NextSampleIdx Index of next location sample in array
Public variable FMoveComplete OnRequestFinished Delegate for move completion notify
Protected variable FVector OriginalMoveRequestGoalLocation This is needed for partial paths when trying to figure out if following a path should finish before reaching path end, due to reaching requested acceptance radius away from original move goal Is being set for non-partial paths as well
Protected variable FNavPathSharedPtr Path Requested path
Protected variable double PathTimeWhenPaused Timestamp of path update when movement was paused
Public variable FPostProcessMoveSignature PostProcessMove Delegate for modifying path following velocity
Protected variable int32 PreciseAcceptanceRadiusCheckStartNodeIndex Indicates a path node index at which precise "is at goal" tests are going to be performed every frame, in regards to acceptance radius
Protected variable FAIResourceLock ResourceLock Used to keep track of which subsystem requested this AI resource be locked
Protected variable TEnumAsByte< EPathFollowingStatus::Type > Status Current status
Protected variable FTimerHandle WaitingForPathTimer Timer handle for OnWaitingPathTimeout function
Protected variable float WaitingTimeout Timeout for Waiting state, negative value = infinite

Constructors

  Type Name Description
Public function  

UPathFollowingComponent ( const FObjectInitializer& ObjectInitializer
)

  

Functions

  Type Name Description
Public function Virtual void

AbortMove ( const UObject& Instigator,
FPathFollowingResultFlags::Type AbortFlags,
FAIRequestID RequestID,
EPathFollowingVelocityMode VelocityMode
)

 Aborts following path
Public function Virtual void

Cleanup ()

 Cleanup component before destroying
Protected function Const void

DebugReachTest ( float& CurrentDot,
float& CurrentDistance,
float& CurrentHeight,
uint8& bDotFailed,
uint8& bDistanceFailed,
uint8& bHeightFailed
)

 Debug point reach test values
Public function Virtual Const void  
Protected function Virtual int32

DetermineCurrentTargetPathPoint ( int32 StartIndex
)

  
Protected function Virtual Const int32

DetermineStartingPathPoint ( const FNavigationPath* ConsideredPath
)

 Checks if this PathFollowingComponent is already on path, and if so determines index of next path point
Public function Const bool  
Public function Virtual Const void

DisplayDebug ( UCanvas* Canvas,
const FDebugDisplayInfo& DebugDisplay,
float& YL,
float& YPos
)

  
Protected function Const int32

FindPreciseAcceptanceRadiusTestsStartNodeIndex ( const FNavigationPath& PathInstance,
const FVector& GoalLocation
)

 For given path finds a path node at which PathfollowingComponent should start doing precise is-goal-in-acceptance-radius tests
Public function Virtual void Call when moving agent finishes using custom nav link, returns control back to path following
Protected function Virtual void

FollowPathSegment ( float DeltaTime
)

 Follow current path segment
Protected function void Force creating new location sample for block detection
Public function Const float  
Public function Const UObject *  
Public function Const FVector  
Public function Const FVector Note that CurrentMoveInput is only valid if MovementComp->UseAccelerationForPathFollowing() == true
Public function Const FNavLocation Returns current location on navigation data
Public function Virtual Const int32 Returns index of the currently followed element of path.
Public function Const uint32  
Public function Const FAIRequestID  
Public function Const FVector  
Public function Const FBasedPosition  
Public function Virtual Const FString  
Public function Virtual Const void  
Public function Const float  
Protected function Const float

GetFinalAcceptanceRadius ( const FNavigationPath& PathInstance,
const FVector OriginalGoalLocation,
const FVector* PathEndOverride
)

 Based on Path's properties, original move goal location and requested AcceptanceRadius this function calculates actual acceptance radius to apply when testing if the agent has successfully reached requested goal's vicinity
Public function Virtual Const FVector

GetMoveFocus ( bool bAllowStrafe
)

 Get current focal point of movement
Public function Const AActor *  
Public function Const FVector  
Public function Const uint32  
Protected function Static uint32  
Public function Const const FNavPathSharedPtr

GetPath ()

  
Public function Const EPathFollowingAction::Type  
Public function Const FVector  
Public function Const FVector::FReal  
Public function Const FString Readable name of result enum
Public function Const EPathFollowingStatus::Type  
Public function Const FString Readable name of current status
Protected function Virtual bool Called after receiving update event from current path
Public function Const bool  
Public function Const bool Check if path following has authority over movement (e.g. not falling) and can update own state
Public function Const bool  
Public function Const bool

HasReached ( const AActor& TestGoal,
EPathFollowingReachMode ReachMode,
float AcceptanceRadius,
bool bUseNavAgentGoalLocation
)

 Simple test for stationary agent (used as early finish condition), check if reached given goal
Public function Const bool

HasReached ( const FVector& TestPoint,
EPathFollowingReachMode ReachMode,
float AcceptanceRadius
)

 Simple test for stationary agent (used as early finish condition), check if reached given point
Public function Const bool

HasReached ( const FAIMoveRequest& MoveRequest
)

 Simple test for stationary agent (used as early finish condition), check if reached target specified in move request
Protected function Virtual Const bool

HasReachedCurrentTarget ( const FVector& CurrentLocation
)

 Check if segment is completed
Protected function Virtual Const bool

HasReachedDestination ( const FVector& CurrentLocation
)

 Check if move is completed
Protected function Const bool

HasReachedInternal ( const FVector& GoalLocation,
float GoalRadius,
float GoalHalfHeight,
const FVector& AgentLocation,
float RadiusThreshold,
float AgentRadiusMultiplier
)

 Check if moving agent has reached goal defined by cylinder
Public function Const bool  
Public function Const bool  
Public function Virtual void Initialize component to use
Public function Const bool  
Protected function Const bool Check if movement is blocked
Public function Const bool  
Public function Const bool Returns true if pathfollowing is doing deceleration at the end of the path.
Protected function Virtual Const bool Check if agent is on path
Public function Virtual Const bool Check if path following can be activated
Public function Const bool  
Public function Static void

LogPathHelper ( const AActor* LogOwner,
FNavigationPath* InLogPath,
const AActor* LogGoalActor
)

 Helper function for sending a path for visual log
Public function Static void

LogPathHelper ( const AActor* LogOwner,
FNavPathSharedPtr InLogPath,
const AActor* LogGoalActor
)

 Helper function for sending a path for visual log
Public function Virtual void

OnActorBump ( AActor* SelfActor,
AActor* OtherActor,
FVector NormalImpulse,
const FHitResult& Hit
)

 Called when moving agent collides with another actor
Protected function void Called when NavigationSystem registers new navigation data type while this component instance has empty MyNavData.
Protected function Virtual void Called when NavigationSystem finishes initial navigation data registration.
Protected function Virtual void

OnNewPawn ( APawn* NewPawn
)

 Called if owning Controller possesses new pawn or ends up pawn-less.
Public function void Path observer
Public function Virtual void Called when owner is preparing new pathfinding request
Public function Virtual void Notify about finished movement
Public function void

OnPathFinished ( EPathFollowingResult::Type ResultCode,
uint16 ExtraResultFlags
)

  
Public function Virtual void Notify about changing current path: new pointer or update from path event
Public function Virtual void Notify about finishing move along current path segment
Protected function Virtual void Called from timer if component spends too much time in Waiting state
Public function Virtual void

PauseMove ( FAIRequestID RequestID,
EPathFollowingVelocityMode VelocityMode
)

 Pause path following
Public function Virtual FAIRequestID

RequestMove ( const FAIMoveRequest& RequestData,
FNavPathSharedPtr InPath
)

 Start movement along path
Public function FAIRequestID

RequestMoveWithImmediateFinish ( EPathFollowingResult::Type Result,
EPathFollowingVelocityMode VelocityMode
)

 Create new request and finish it immediately (e.g. already at goal)
Protected function Virtual void

Reset ()

 Reset path following data
Protected function void Clears Block Detection stored data effectively resetting the mechanism
Public function Virtual void

ResumeMove ( FAIRequestID RequestID
)

 Resume path following
Public function void

SetAcceptanceRadius ( const float InAcceptanceRadius
)

  
Public function void

SetBlockDetection ( float DistanceThreshold,
float Interval,
int32 NumSamples
)

 Set block detection params
Public function void

SetBlockDetectionState ( bool bEnable
)

 Update state of block detection
Public function void

SetDestinationActor ( const AActor* InDestinationActor
)

  
Public function void

SetLastMoveAtGoal ( bool bFinishedAtGoal
)

 Set status of last requested move, works only in Idle state
Public function Virtual void Set associated movement component
Protected function Virtual void

SetMoveSegment ( int32 SegmentStartIndex
)

 Sets variables related to current move segment
Protected function void Switch to next segment on path
Public function void

SetPreciseReachThreshold ( float AgentRadiusMultiplier,
float AgentHalfHeightMultiplier
)

 Set threshold for precise reach tests in intermediate goals (minimal test radius)
Public function void

SetStopMovementOnFinish ( bool bEnable
)

 Set whether movement is stopped on finish of move.
Protected function Virtual Const bool Should verify if agent if still on path ater movement has been resumed?
Protected function Virtual Const bool Defines if the agent should reset his velocity when the path is finished
Protected function Virtual void

StartUsingCustomLink ( INavLinkCustomInterface* CustomNavLink,
const FVector& DestPoint
)

 Next path segment if custom nav link, try passing control to it
Protected function void Assign new request Id
Protected function Virtual bool Update blocked movement detection,
Public function Virtual void Updates cached pointers to relevant owner's components
Protected function Virtual void Updates braking distance and deceleration segment
Protected function Virtual void Set move focus in AI owner
Protected function Virtual bool

UpdateMovementComponent ( bool bForce
)

 Check if movement component is valid or tries to grab one from owner
Protected function Virtual void Check state of path following, update move segment if needed

Overridden from UActorComponent

  Type Name Description
Public function Virtual void Called when a component is registered, after Scene is set, but before CreateRenderState_Concurrent or OnCreatePhysicsState are called.
Public function Virtual void

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

 Function called every frame on this ActorComponent.

Overridden from IAIResourceInterface

  Type Name Description
Public function Virtual void Clear resource lock of the given origin
Public function Virtual void Force-clears all locks on resource
Public function Virtual Const bool Check whether resource is currently locked
Public function Virtual void If resource is lockable lock it with indicated priority

Overridden from IPathFollowingAgentInterface

  Type Name Description
Public function Virtual void Called when falling movement ends.
Public function Virtual void Virtual void OnMoveBlockedBy(const FHitResult& BlockingImpact) {}
Public function Virtual void

OnUnableToMove ( const UObject& Instigator
)

 Called when pathfollowing agent is not able to move anymore

Typedefs

Name Description
FMoveComplete  
FMoveCompletedSignature  
FPostProcessMoveSignature  
FRequestCompletedSignature  

Constants

Name Description
DefaultAcceptanceRadius Special float constant to symbolize "use default value".
NextRequestId Used for debugging purposes to be able to identify which logged information results from which request, if there was multiple ones during one frame

Deprecated Variables

  Type Name Description
Public variable FMoveCompletedSignature OnMoveFinished_DEPRECATED This delegate is now deprecated, please use OnRequestFinished instead.

Ask questions and help your peers Developer Forums

Write your own tutorials or read those from others Learning Library

On this page