---
title: "init(indexOffset:indexCount:topology:materialIndex:bounds:)"
framework: realitykit
role: symbol
role_heading: Initializer
path: "realitykit/lowlevelmesh/part/init(indexoffset:indexcount:topology:materialindex:bounds:)"
---

# init(indexOffset:indexCount:topology:materialIndex:bounds:)

Creates a low-level mesh part.

## Declaration

```swift
init(indexOffset: Int = 0, indexCount: Int = 0, topology: MTLPrimitiveType = .triangle, materialIndex: Int = 0, bounds: BoundingBox)
```

## Parameters

- `indexOffset`: The offset, in bytes, of the first index.
- `indexCount`: The number of indices to use for this part.
- `topology`: The geometric primitive to use when rendering this part.
- `materialIndex`: The material index this part associates with.
- `bounds`: The model-space bounding box of the part.