MotionJumpComponent

MotionJumpComponent manages jump intent, multi-jump, coyote time, jump buffering, landing feedback, and server-authoritative validation.

Requirements

• Character with standard UCharacterMovementComponent
• A resolvable UAbilitySystemComponent, commonly exposed by a PlayerState that implements IAbilitySystemInterface
• Gameplay Ability System initialized
• Enhanced Input configured
• Wants-to-jump and jumping GameplayEffects
• GameplayTags for jump intent, active jumping, and jump availability

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

Behavior

The component stores jump input, checks whether a jump can execute, applies direct jump velocity, manages coyote time and input buffering, resets jump count on landing, and broadcasts camera, sound, and Blueprint feedback.

Coyote time allows a jump shortly after leaving the ground. Jump buffering stores input shortly before landing and executes it when the character becomes valid for jumping.

API

Jump state

• SetWantsToJump(bool bWantsToJump) -> void: sets jump intent.
• GetWantsToJump() -> bool: returns jump intent.
• IsCurrentlyJumping() -> bool: returns air/jump state.
• CanJump() -> bool: checks whether another jump can execute.
• TriggerJump(bool bIsAdditionalJump) -> bool: manually triggers a jump.
• CanPerformJump() -> bool: validates all jump conditions.
• PerformJump(bool bIsAdditionalJump) -> bool: executes the jump.
• GetRemainingJumps() -> int32: returns available additional jumps.
• HandleLanding() -> void: handles landing reset and feedback.

Timers and state management

• UpdateCoyoteTime(float DeltaTime) -> void: updates coyote time.
• UpdateJumpBuffer(float DeltaTime) -> void: updates buffered input.
• IsInCoyoteTime() -> bool: checks whether coyote time is active.
• IsJumpBuffered() -> bool: checks whether input is buffered.
• UpdateJumpingState(float DeltaTime) -> void: updates jump state.
• InitializeJumpComponent() -> void: initializes cached references.
• OnAbilitySystemComponentReady() -> void: performs GAS setup.
• GrantJumpAbilityTag() -> void: grants the jump ability tag.

Velocity, camera, and input

• ApplyDirectJumpVelocity(bool bIsAdditionalJump) -> void: applies direct jump velocity.
• StartJumpCameraEffects() -> void: starts jump camera feedback.
• StopJumpCameraEffects() -> void: stops jump camera feedback.
• StartLandingCameraEffects() -> void: starts landing camera feedback.
• StopLandingCameraEffects() -> void: stops landing camera feedback.
• StartCameraShake(const FMotionCurve&, int32&) -> void: starts a reusable camera effect.
• StopCameraShake(const FMotionCurve&, int32&) -> void: stops a reusable camera effect.
• OnInputStarted(FInputActionValue&) -> void: handles jump input press.
• OnInputCompleted(FInputActionValue&) -> void: handles jump input release.
• HandleJumpInputStateChange(bool bPressed) -> void: processes jump input state.
• BindJumpInput(UInputAction*) -> bool: binds jump input through auto-discovery.
• BindJumpInputWithComponent(UInputAction*, UEnhancedInputComponent*) -> bool: binds jump input through an explicit input component.

Networking

• ServerRequestJump(bool bWantsToJump) -> void: server RPC for jump validation.
• MulticastJumpFeedback(bool bJumped, int32 JumpNumber) -> void: multicasts jump feedback.
• MulticastLandingFeedback() -> void: multicasts landing feedback.

Configuration

Configuration lives on the assigned MotionJumpProfile. The current Motion default is /MotionCore/Motion/Profiles/v2_0_0/DA_MotionJumpProfile_Default_v2_0_0.

Jump settings

• JumpVelocityMultiplier: jump velocity multiplier. Default: 1.0.
• JumpVelocityModifier: absolute jump velocity added. Default: 0.0.
• bEnableMultiJump: whether multi-jump is enabled. Default: false.
• MaxAdditionalJumps: number of additional airborne jumps. Default: 1.
• AdditionalJumpVelocityMultiplier: velocity multiplier for additional jumps. Default: 0.8.

Responsiveness settings

• CoyoteTime: grace period after leaving ground. Default: 0.15.
• JumpBufferTime: time to keep jump input buffered. Default: 0.2.

Effects and feedback

• JumpCameraShake: camera curve during jump.
• LandingCameraShake: camera curve when landing.
• bApplyCameraShake: whether camera shake is applied.
• bAutoTriggerLandingSound: whether landing sounds are triggered automatically.
• WantsToJumpTagEffect: grants wants-to-jump tag.
• JumpingTagEffect: grants jumping state tag.

The component's editable setup surface is the Profile reference. Input buffers, coyote timers, jump counts, camera curve playback identifiers, and replicated state remain component-owned.

Read-Only State

• JumpCameraShakeIdentifier: identifier for jump camera shake.
• LandingCameraShakeIdentifier: identifier for landing camera shake.
• CachedMovementSoundComponent: cached sound component reference.
• MotionJumpCount: replicated jump counter.
• LastGroundedTime: time the character last left ground.
• LastJumpInputTime: time jump input was last pressed.
• OriginalJumpZVelocity: jump Z velocity cached at BeginPlay.
• bWasGroundedLastFrame: previous grounded state.
• bWasJumpingLastFrame: previous jumping state.
• bActuallyJumped: tracks whether the component performed a jump.
• bUsedCoyoteJump: tracks whether coyote jump was used.
• bJumpButtonReleasedSinceLastAirJump: prevents held-button multi-jump.
• bJumpInputTriggeredThisFrame: frame-level input flag.
• LastJumpRPCTime: server-side RPC rate limit timestamp.
• bCoyoteExpiredLastFrame: coyote expiration event guard.
• bBufferExpiredLastFrame: buffer expiration event guard.

Blueprint Events

• OnJumpStateChanged(bool bIsJumping): fires when jump state changes.
• OnJumpPerformed(bool bIsAdditionalJump, int32 JumpNumber): fires when a jump executes.
• OnLanded(): fires when the character lands.
• OnCoyoteTimeExpired(): fires when coyote time expires.
• OnJumpBufferExpired(): fires when buffered input expires.

Networking

Jumping uses server RPC validation, multicast feedback, local prediction, and authority-based reconciliation.