---
title: MTL4AccelerationStructureMotionBoundingBoxGeometryDescriptor
framework: metal
role: symbol
role_heading: Class
path: metal/mtl4accelerationstructuremotionboundingboxgeometrydescriptor
---

# MTL4AccelerationStructureMotionBoundingBoxGeometryDescriptor

Describes motion bounding box geometry, suitable for motion ray tracing.

## Declaration

```swift
class MTL4AccelerationStructureMotionBoundingBoxGeometryDescriptor
```

## Overview

Overview You use bounding boxes to implement procedural geometry for ray tracing, such as spheres or any other shape you define by using intersection functions. Use a MTLResidencySet to mark residency of all buffers this descriptor references when you build this acceleration structure.

## Topics

### Instance Properties

- [boundingBoxBuffers](metal/mtl4accelerationstructuremotionboundingboxgeometrydescriptor/boundingboxbuffers.md)
- [boundingBoxCount](metal/mtl4accelerationstructuremotionboundingboxgeometrydescriptor/boundingboxcount.md)
- [boundingBoxStride](metal/mtl4accelerationstructuremotionboundingboxgeometrydescriptor/boundingboxstride.md)

## Relationships

### Inherits From

- [MTL4AccelerationStructureGeometryDescriptor](metal/mtl4accelerationstructuregeometrydescriptor.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCopying](foundation/nscopying.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Motion geometry descriptors

- [MTL4AccelerationStructureMotionTriangleGeometryDescriptor](metal/mtl4accelerationstructuremotiontrianglegeometrydescriptor.md)
- [MTLAccelerationStructureMotionTriangleGeometryDescriptor](metal/mtlaccelerationstructuremotiontrianglegeometrydescriptor.md)
- [MTL4AccelerationStructureMotionCurveGeometryDescriptor](metal/mtl4accelerationstructuremotioncurvegeometrydescriptor.md)
- [MTLAccelerationStructureMotionCurveGeometryDescriptor](metal/mtlaccelerationstructuremotioncurvegeometrydescriptor.md)
- [MTLAccelerationStructureMotionBoundingBoxGeometryDescriptor](metal/mtlaccelerationstructuremotionboundingboxgeometrydescriptor.md)
- [MTLMotionKeyframeData](metal/mtlmotionkeyframedata.md)