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# indexBuffer

An object that provides index data for the submesh.

```
var indexBuffer: any MDLMeshBuffer { get }
```

## Discussion

An index buffer contains indices, each of which identifies a vertex in the vertex buffers of the [`MDLMesh`](/documentation/ModelIO/MDLMesh) object containing the mesh. Together with the submesh’s [`geometryType`](/documentation/ModelIO/MDLSubmesh/geometryType) property, the sequence of indices determines how to interpret the mesh’s vertex data to construct the geometric form for a portion of the mesh.

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