---
title: "init(semantic:format:layoutIndex:offset:)"
framework: realitykit
role: symbol
role_heading: Initializer
path: "realitykit/lowlevelmeshresource/attribute/init(semantic:format:layoutindex:offset:)"
---

# init(semantic:format:layoutIndex:offset:)

Creates an attribute with the given semantic, format, layout index, and byte offset.

## Declaration

```swift
init(semantic: LowLevelMeshResource.VertexSemantic, format: MTLVertexFormat, layoutIndex: Int = 0, offset: Int)
```

## Parameters

- `semantic`: The semantic describing how the renderer interprets this attribute.
- `format`: The Metal vertex format of the attribute.
- `layoutIndex`: The index of the layout that contains this attribute. Defaults to 0.
- `offset`: The byte offset of this attribute from the start of the vertex data.