---
title: bounds
framework: realitykit
role: symbol
role_heading: Instance Property
path: realitykit/lowlevelmesh/part/bounds
---

# bounds

The model-space bounding box of this part.

## Declaration

```swift
var bounds: BoundingBox
```

## Discussion

Discussion RealityKit uses this bounding box for culling the mesh against the active camera. Take care to maintain the bounds of each mesh part so that it completely contains the part’s geometry. Otherwise, RealityKit may not render your meshes correctly.

## See Also

### Describing a low-level mesh part

- [indexOffset](realitykit/lowlevelmesh/part/indexoffset.md)
- [indexCount](realitykit/lowlevelmesh/part/indexcount.md)
- [topology](realitykit/lowlevelmesh/part/topology.md)
- [materialIndex](realitykit/lowlevelmesh/part/materialindex.md)