---
title: trimStart
framework: realitykit
role: symbol
role_heading: Instance Property
path: realitykit/sampledanimation/trimstart
---

# trimStart

The optional time, in seconds, at which the animation plays.

## Declaration

```swift
var trimStart: TimeInterval? { get set }
```

## Discussion

Discussion This property is nil by default, which plays the animation from the starting frame defined by start. If you set a value for this property, the animation visually begins from an additional seconds offset from the starting frame and decreases the duration by that amount. If you set a negative value for this property, the duration increases and the additional animation data fills in based on the fillMode you choose.

## See Also

### Timing the animation

- [frameInterval](realitykit/sampledanimation/frameinterval.md)
- [start](realitykit/sampledanimation/start.md)
- [end](realitykit/sampledanimation/end.md)
- [speed](realitykit/sampledanimation/speed.md)
- [delay](realitykit/sampledanimation/delay.md)
- [duration](realitykit/sampledanimation/duration.md)
- [offset](realitykit/sampledanimation/offset.md)
- [trimDuration](realitykit/sampledanimation/trimduration.md)
- [trimEnd](realitykit/sampledanimation/trimend.md)