---
title: SCNActionTimingFunction
framework: scenekit
role: symbol
role_heading: Type Alias
path: scenekit/scnactiontimingfunction
---

# SCNActionTimingFunction

The signature for a block that manages animation timing, used by the timingFunction property.

## Declaration

```swift
typealias SCNActionTimingFunction = (Float) -> Float
```

## Discussion

Discussion The block takes a single parameter: Your block must return a floating-point value between 0.0 and 1.0, where 0.0 represents the starting state of the action’s animation and 1.0 represents the end state.

## See Also

### Constants

- [SCNActionTimingMode](scenekit/scnactiontimingmode.md)