---
title: "init(from:to:timing:isAdditive:)"
framework: realitykit
role: symbol
role_heading: Initializer
path: "realitykit/fromtobyaction/init(from:to:timing:isadditive:)"
---

# init(from:to:timing:isAdditive:)

Creates a new action that interpolates towards a specified final value.

## Declaration

```swift
init(from: Value? = nil, to: Value, timing: AnimationTimingFunction = .linear, isAdditive: Bool = false)
```

## Parameters

- `from`: Value set at the start of the animation, or nil to use the default source.
- `to`: Value set at the end of the animation.
- `timing`: Controls the progress of the animation.
- `isAdditive`: A Boolean value that indicates whether the animation system additively blends the action’s output with the base value.

## Discussion

Discussion from → to or defaultSource → to