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# LowLevelMeshPart

An object that describes a range of primitives to draw from a mesh resource.

```
final class LowLevelMeshPart
```

## Overview

A mesh part selects a contiguous range of indices from the mesh’s index buffer and associates
it with a primitive type, winding order, and bounding volume.

Create a `LowLevelMeshPart` using
[`makeMeshPart(resource:indexOffset:indexCount:primitive:windingOrder:bounds:)`](/documentation/RealityKit/LowLevelRenderContext/makeMeshPart(resource:indexOffset:indexCount:primitive:windingOrder:bounds:)).

## Topics

### Configuring the geometry

[`var primitive: MTLPrimitiveType`](/documentation/RealityKit/LowLevelMeshPart/primitive)

The geometric primitive to use when rendering this part.

[`var windingOrder: MTLWinding`](/documentation/RealityKit/LowLevelMeshPart/windingOrder)

The winding order of front-facing polygons.

[`func setIndexRange(indexOffset: Int, indexCount: Int) throws(LowLevelRenderContextError)`](/documentation/RealityKit/LowLevelMeshPart/setIndexRange(indexOffset:indexCount:))

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

### Instance Properties

[`var bounds: BoundingSphereBox`](/documentation/RealityKit/LowLevelMeshPart/bounds)

The bounding volume of this mesh part, in model space.

[`var indexCount: Int`](/documentation/RealityKit/LowLevelMeshPart/indexCount)

The number of indices to use for this part.

[`var indexOffset: Int`](/documentation/RealityKit/LowLevelMeshPart/indexOffset)

The byte offset of the first index.

[`var resource: LowLevelMeshResource`](/documentation/RealityKit/LowLevelMeshPart/resource)

The mesh resource whose index and vertex buffers this part draws from.

---

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