---
title: voxelIndexExtent
framework: modelio
role: symbol
role_heading: Instance Property
path: modelio/mdlvoxelarray/voxelindexextent
---

# voxelIndexExtent

The indexes that define the corners of the three-dimensional voxel grid.

## Declaration

```swift
var voxelIndexExtent: MDLVoxelIndexExtent { get }
```

## Discussion

Discussion This property determines which MDLVoxelIndex values are valid for referring to the contents of the voxel array using methods such as setVoxelAtIndex(_:) or voxelBoundingBox(atIndex:). For example, if the minimum extent is {0, 0, 0, 0} and the maximum extent is {10, 10, 10, 0}, the voxel index {5, 5, 5, 0} lies within the array but the voxel index {0, 20, 10, 0} does not.

## See Also

### Examining Voxels

- [count](modelio/mdlvoxelarray/count.md)
- [voxelExists(atIndex:allowAnyX:allowAnyY:allowAnyZ:allowAnyShell:)](modelio/mdlvoxelarray/voxelexists(atindex:allowanyx:allowanyy:allowanyz:allowanyshell:).md)
- [voxels(within:)](modelio/mdlvoxelarray/voxels(within:).md)
- [voxelIndices()](modelio/mdlvoxelarray/voxelindices().md)