---
title: once
framework: realitykit
role: symbol
role_heading: Type Property
path: realitykit/anchoringcomponent/trackingmode-swift.struct/once
---

# once

Anchors the entity to the target on the first frame the target is found.

## Declaration

```swift
static let once: AnchoringComponent.TrackingMode
```

## Discussion

Discussion once means the Entity transform is evaluated only once when the target anchor presents and the Entity is anchored. If the target anchor moves or disappears later, the Entity stays in place.