Timeline — animate values over time with a curve

Timeline is a special node — NOT a function call. Create by right-click → Add Timeline. Add float/vector/color tracks in the editor. Exec inputs: 'Play', 'PlayFromStart', 'Stop', 'Reverse', 'ReverseFromEnd', 'Set New Time'. Exec outputs: 'Update' (fires every frame while playing) and 'Finished'. Data output per track is named after the track. 'Direction' is ETimelineDirection enum.

Elevator or moving platform with timeline and trigger

Pattern: Variables StartLocation(Vector), EndLocation(Vector). BeginPlay: SET StartLocation=GetActorLocation. Timeline MoveTimeline(Alpha 0→1 over Duration). Trigger overlap/button press → Play Timeline. Timeline Update: VLerp(StartLocation, EndLocation, Alpha) → SetActorLocation(Self, Result, bSweep=true). Finished: Delay → Reverse Timeline.

Door open and close with timeline and trigger volume

Pattern: Door actor with BoxTrigger, DoorMesh, Timeline(Alpha 0→1 over 1s). BeginOverlap → PlayFromStart(Timeline). EndOverlap → Reverse(Timeline). Timeline Update: Lerp(ClosedRotation, OpenRotation, Alpha) → SetRelativeRotation(DoorMesh). For sliding: Lerp locations instead of rotations.

Timeline-driven door opening animation

Variables: StartRotation (Rotator), EndRotation (Rotator), bIsOpen (bool). Add Timeline node with a float track 'Alpha' (curve from 0.0 to 1.0, duration 1.0s). Overlap trigger → Branch(bIsOpen) → False: Timeline.Play → Update: RLerp(A=StartRotation,B=EndRotation,Alpha=Alpha) → SetActorRotation → Finished: SetVariable(bIsOpen=true). True: Timeline.Reverse → Update: same RLerp → Finished: SetVariable(bIsOpen=false). Key Timeline pins: Play exec input opens forward. Reverse plays backward. Update fires every frame. Finished fires when complete. Alpha track outputs 'Alpha' float.

Dash or dodge movement with cooldown using timeline

Pattern: Variables bCanDash(bool)=true, DashDistance(float)=1000, DashDuration(float)=0.2. Input → Branch(bCanDash) → SET bCanDash=false → GetActorForwardVector → Multiply(Forward, DashDistance) → Timeline(0→1 over DashDuration) → Update: VLerp(StartLoc, StartLoc+DashOffset, Alpha) → SetActorLocation. Finished → Delay(CooldownTime) → SET bCanDash=true.

Create a Blueprint Actor with a timeline that smoothly interpolates between two locations over 2 seconds

Lerp

Linear interpolation — returns A when Alpha=0, B when Alpha=1, and a smooth blend in between. Pair with Timeline for animation.

Health regeneration over time with timer

Pattern: Variables RegenRate(float)=5.0, RegenDelay(float)=3.0, RegenTimerHandle. On damage received: ClearTimer(RegenTimerHandle) → SET timer(RegenDelay, RegenTick, looping=true). RegenTick function: Branch(Health < MaxHealth) → True: SET Health = FClamp(Health + RegenRate*DeltaSeconds, 0, MaxHealth). False: ClearTimer.

string

string

GetTimeSeconds — get time since level started