---
title: "setIndexRange(indexOffset:indexCount:)"
framework: realitykit
role: symbol
role_heading: Instance Method
path: "realitykit/lowlevelmeshpart/setindexrange(indexoffset:indexcount:)"
---

# setIndexRange(indexOffset:indexCount:)

Updates the first index and index count for this mesh part.

## Declaration

```swift
final func setIndexRange(indexOffset: Int, indexCount: Int) throws(LowLevelRenderContextError)
```

## Parameters

- `indexOffset`: The byte offset of the first index within the index buffer.
- `indexCount`: The number of indices to use for this part.

## Discussion

Discussion Throws LowLevelRenderContextError if the resulting range falls outside the mesh resource’s index buffer. note: LowLevelRenderContextError if the resulting range falls outside the mesh resource’s index buffer.

## See Also

### Configuring the geometry

- [primitive](realitykit/lowlevelmeshpart/primitive.md)
- [windingOrder](realitykit/lowlevelmeshpart/windingorder.md)