MotionJumpComponent

The Jump Component manages multi-jump, coyote time, and jump buffering. It supports client prediction with server-authoritative validation.

Requirements

Character with standard UCharacterMovementComponent
A resolvable UAbilitySystemComponent, commonly exposed by a PlayerState that implements IAbilitySystemInterface
Gameplay Ability System (GAS) initialized
Enhanced Input System configured
Gameplay Effects:
- GE_Motion_WantsToJump - Grants wants to jump tag
- GE_Motion_Jumping - Grants jumping state tag
Gameplay Tags:
- Motion.State.WantsToJump - Player input to jump
- Motion.State.Jumping - Active jumping/falling state
- Motion.Ability.CanJump - Required ability tag (auto-granted by component)

For setup and input binding steps, see How to add Motion to a character.

Functionality

Jump State Machine

Jump Validation Flow

Update Cycle

Expandability

The MotionJumpComponent provides extensive virtual functions for customization:

Core Jump Functions

Function	Parameters	Returns	Use Case Examples
`SetWantsToJump()`	bool bWantsToJump	void	• Add stamina cost • Check prerequisites
`GetWantsToJump()`	None	bool	• Query jump intent • UI state display
`IsCurrentlyJumping()`	None	bool	• Check air state • Animation triggers
`CanJump()`	None	bool	• Add conditions • Equipment checks
`TriggerJump()`	bool bIsAdditionalJump	bool	• Manual jump • Ability trigger

Jump State Functions

Function	Parameters	Returns	Use Case Examples
`CanPerformJump()`	None	bool	• Validate conditions • Check resources
`PerformJump()`	bool bIsAdditionalJump	bool	• Execute jump • Apply modifiers
`GetRemainingJumps()`	None	int32	• UI display • Ability checks
`HandleLanding()`	None	void	• Landing logic • Fall damage

Timer System Functions

Function	Parameters	Returns	Use Case Examples
`UpdateCoyoteTime()`	float DeltaTime	void	• Grace period • Platform forgiveness
`UpdateJumpBuffer()`	float DeltaTime	void	• Input queue • Responsive controls
`IsInCoyoteTime()`	None	bool	• Check grace • Allow late jump
`IsJumpBuffered()`	None	bool	• Check buffer • Process queue

State Management Functions

Function	Parameters	Returns	Use Case Examples
`UpdateJumpingState()`	float DeltaTime	void	• Core update • State machine
`InitializeJumpComponent()`	None	void	• Setup refs • Cache values
`OnAbilitySystemComponentReady()`	None	void	• GAS setup • Grant abilities
`GrantJumpAbilityTag()`	None	void	• Add tags • Enable jump

Velocity Modification Functions

Function	Parameters	Returns	Use Case Examples
`ApplyDirectJumpVelocity()`	bool bIsAdditionalJump	void	• Direct control • Custom physics

Camera Effect Functions

Function	Parameters	Returns	Use Case Examples
`StartJumpCameraEffects()`	None	void	• Jump shake • FOV change
`StopJumpCameraEffects()`	None	void	• End shake • Reset view
`StartLandingCameraEffects()`	None	void	• Impact shake • Landing feel
`StopLandingCameraEffects()`	None	void	• End effects • Smooth reset
`StartCameraShake()`	const FMotionCurve&, int32&	void	• Generic shake • Reusable effect
`StopCameraShake()`	const FMotionCurve&, int32&	void	• Stop by curve • Clean up

Input System Functions

Function	Parameters	Returns	Use Case Examples
`OnInputStarted()`	FInputActionValue&	void	• Jump press • Buffer input
`OnInputCompleted()`	FInputActionValue&	void	• Release • Variable height
`HandleJumpInputStateChange()`	bool bPressed	void	• Process input • State change
`BindJumpInput()`	UInputAction*	bool	• Bind action • Setup input
`BindJumpInputWithComponent()`	UInputAction, UEnhancedInputComponent	bool	• Explicit bind • Custom comp

Utility Functions

Function	Parameters	Returns	Use Case Examples
`PrintDebugInformation()`	None	void	• Debug display • State logging

Blueprint Events

Event	Parameters	Use Case Examples
`OnJumpStateChanged`	bool bIsJumping	• Animation triggers • State UI
`OnJumpPerformed`	bool bIsAdditionalJump, int32 JumpNumber	• Jump VFX • Sound variation
`OnLanded`	None	• Landing animation • Fall damage
`OnCoyoteTimeExpired`	None	• Grace ended • UI indicator
`OnJumpBufferExpired`	None	• Buffer cleared • Input feedback

Network Functions

Function	Parameters	Returns	Use Case Examples
`ServerRequestJump()`	bool bWantsToJump	void (RPC)	• Server validation • Authority check
`MulticastJumpFeedback()`	bool bJumped, int32 JumpNumber	void (RPC)	• Visual sync • Other clients
`MulticastLandingFeedback()`	None	void (RPC)	• Landing sync • Effects broadcast

Configuration

Jump Settings

Property	Type	Default	Description	Range
JumpVelocityMultiplier	float	1.0	Jump velocity multiplier (1.0 = default UE behavior)	0.1 - 5.0
JumpVelocityModifier	float	0.0	Absolute jump velocity to add	-
bEnableMultiJump	bool	false	Whether to enable multi-jump functionality	-
MaxAdditionalJumps	int32	1	Maximum number of additional jumps after initial	0 - 10
AdditionalJumpVelocityMultiplier	float	0.8	Velocity multiplier for additional jumps	0.1 - 2.0

Advanced Features

Property	Type	Default	Description	Range
CoyoteTime	float	0.15	Grace period to jump after leaving ground (seconds)	0.0 - 1.0
JumpBufferTime	float	0.2	Allow jump input buffering when not grounded (seconds)	0.0 - 1.0

Camera Effects

Property	Type	Default	Description
JumpCameraShake	FMotionCurve	-	Camera shake curve during jumping
LandingCameraShake	FMotionCurve	-	Camera shake curve when landing
bApplyCameraShake	bool	true	Whether to apply camera shake

Sound

Property	Type	Default	Description	Range
bAutoTriggerLandingSound	bool	true	Auto-trigger landing sounds vs Animation Notifies	-

GAS Integration

Property	Type	Description
WantsToJumpTagEffect	`TSubclassOf<UGameplayEffect>`	Grants wants to jump tag
JumpingTagEffect	`TSubclassOf<UGameplayEffect>`	Grants jumping state tag

State Tracking (Read-Only)

Property	Type	Description
JumpCameraShakeIdentifier	FName	Unique identifier for jump camera shake
LandingCameraShakeIdentifier	FName	Unique identifier for landing camera shake
CachedMovementSoundComponent	UMotionMovementSoundComponent*	Reference to sound component
MotionJumpCount	int32	Reliable jump counter (Replicated)

Internal State Tracking (Read-Only)

Property	Type	Description
LastGroundedTime	float	Time when character last left ground (for coyote time)
LastJumpInputTime	float	Time when jump input was last pressed (for buffering)
OriginalJumpZVelocity	float	Original jump Z velocity cached at BeginPlay
bWasGroundedLastFrame	bool	Previous frame's grounded state
bWasJumpingLastFrame	bool	Previous frame's jumping state
bActuallyJumped	bool	Track if we performed a jump (not just falling)
bUsedCoyoteJump	bool	Track if coyote jump was used
bJumpButtonReleasedSinceLastAirJump	bool	Prevents held-button multi-jump exploit
bJumpInputTriggeredThisFrame	bool	Frame-level input state tracking
LastJumpRPCTime	float	Server-side RPC rate limiting timestamp
bCoyoteExpiredLastFrame	bool	Track coyote time expiration event
bBufferExpiredLastFrame	bool	Track buffer expiration event

Debug

Property	Type	Default	Description
bShowDebugInformation	bool	false	Debug information display

Input binding API

The component exposes these input binding entry points:

cpp

// Blueprint binding
BindJumpInput(JumpInputAction);

// C++ with explicit component
BindJumpInputWithComponent(JumpAction, EnhancedInputComponent);

// Manual jump trigger (bypasses input)
TriggerJump(bIsAdditionalJump);

Jump State Access

Query jump state for gameplay logic:

GetWantsToJump() - Check if player wants to jump (input pressed)
IsCurrentlyJumping() - Check if character is jumping or falling
GetRemainingJumps() - Get remaining jumps available
IsInCoyoteTime() - Check if within coyote time window
IsJumpBuffered() - Check if jump input is buffered
CanJump() - Check if character can perform another jump

Coyote Time & Jump Buffering

Coyote Time Visualization

Coyote Time: Grace period after leaving a platform where jumping is still allowed

Prevents frustration from barely missing platform edges
Only applies to first jump (not multi-jumps)
Tracked via LastGroundedTime and bUsedCoyoteJump

Jump Buffering: Input queuing system for responsive controls

Stores jump input when pressed before landing
Automatically executes when landing occurs
Makes precise platforming more forgiving

Multi-Jump System

Motion implements a custom counter, because the built-in one tends to count incorrectly due to a bug of Unreal Engine.

Multi-Jump Flow

When enabled, allows additional jumps while airborne:

Jump Count tracked via MotionJumpCount (reliable counter)
Server Validation via server-side CanPerformJump() validation
Velocity Reduction per additional jump for balance
Dynamic Upgrades by modifying MaxAdditionalJumps at runtime

Networking

The component handles multiplayer through:

Server RPCs - ServerRequestJump() for validation
Multicast Events - Visual feedback to all clients
Server Validation - Jump conditions checked on authority
Client Prediction - Immediate local response
State Reconciliation - Authority-based validation

MotionJumpComponent ​

Requirements ​

Functionality ​

Jump State Machine ​

Jump Validation Flow ​

Update Cycle ​

Expandability ​

Core Jump Functions ​

Jump State Functions ​

Timer System Functions ​

State Management Functions ​

Velocity Modification Functions ​

Camera Effect Functions ​

Input System Functions ​

Utility Functions ​

Blueprint Events ​

Network Functions ​

Configuration ​

Jump Settings ​

Advanced Features ​

Camera Effects ​

Sound ​

GAS Integration ​

State Tracking (Read-Only) ​

Internal State Tracking (Read-Only) ​

Debug ​

Input binding API ​

Jump State Access ​

Coyote Time & Jump Buffering ​

Coyote Time Visualization ​

Multi-Jump System ​

Multi-Jump Flow ​

Networking ​