Smooth zoom with mouse wheel on spring arm camera

Pattern: Variables TargetArmLength(float), MinZoom(float)=200, MaxZoom(float)=2000, ZoomStep(float)=50, ZoomSpeed(float)=5. InputAxis MouseWheel: TargetArmLength = FClamp(TargetArmLength - AxisValue*ZoomStep, MinZoom, MaxZoom). Tick: SpringArm.TargetArmLength = FInterpTo(Current, TargetArmLength, DeltaSeconds, ZoomSpeed). FInterpTo provides smooth easing.