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# smooth(duration:extraBounce:)

A smooth spring with a predefined duration and no bounce that can be
tuned.

```
@export(implementation) static func smooth(duration: TimeInterval = 0.5, extraBounce: Double = 0.0) -> Spring
```

## Parameters

`duration`

The perceptual duration, which defines the pace of the
spring. This is approximately equal to the settling duration, but
for very bouncy springs, will be the duration of the period of
oscillation for the spring.

`extraBounce`

How much additional bounce should be added to the base
bounce of 0.

---

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