---
title: "add(to:layerOffset:position:)"
framework: usdkit
role: symbol
role_heading: Instance Method
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, macOS 27.0+, tvOS 27.0+, visionOS 27.0+]
path: "usdkit/usdprim/referencecollection/add(to:layeroffset:position:)"
---

# add(to:layerOffset:position:)

Adds an internal reference arc that targets a prim in the same layer stack.

## Declaration

```swift
func add(to primPath: USDLayer.Path, layerOffset: USDLayer.TimeOffset = .init(), position: USDPrim.ListPosition = .backOfPrependList) throws
```

## Parameters

- `primPath`: The path of the target prim within the same layer stack.
- `layerOffset`: Time offset and scale to apply during composition.
- `position`: Where to insert the reference in the prim’s reference list.

## Discussion

Discussion note: An error if the reference cannot be added.