---
title: MTLIndirectAccelerationStructureInstanceDescriptor
framework: metal
role: symbol
role_heading: Structure
path: metal/mtlindirectaccelerationstructureinstancedescriptor
---

# MTLIndirectAccelerationStructureInstanceDescriptor

A description of an instance in an instanced geometry acceleration structure that the GPU can populate.

## Declaration

```swift
struct MTLIndirectAccelerationStructureInstanceDescriptor
```

## Overview

Overview This memory layout corresponds to the MTLAccelerationStructureInstanceDescriptorType.indirect instance type.

## Topics

### Initializers

- [init()](metal/mtlindirectaccelerationstructureinstancedescriptor/init().md)
- [init(transformationMatrix:options:mask:intersectionFunctionTableOffset:userID:accelerationStructureID:)](metal/mtlindirectaccelerationstructureinstancedescriptor/init(transformationmatrix:options:mask:intersectionfunctiontableoffset:userid:accelerationstructureid:).md)

### Instance Properties

- [accelerationStructureID](metal/mtlindirectaccelerationstructureinstancedescriptor/accelerationstructureid.md)
- [intersectionFunctionTableOffset](metal/mtlindirectaccelerationstructureinstancedescriptor/intersectionfunctiontableoffset.md)
- [mask](metal/mtlindirectaccelerationstructureinstancedescriptor/mask.md)
- [options](metal/mtlindirectaccelerationstructureinstancedescriptor/options.md)
- [transformationMatrix](metal/mtlindirectaccelerationstructureinstancedescriptor/transformationmatrix.md)
- [userID](metal/mtlindirectaccelerationstructureinstancedescriptor/userid.md)

## Relationships

### Conforms To

- [Sendable](swift/sendable.md)

## See Also

### Instance descriptors

- [MTLAccelerationStructureInstanceDescriptor](metal/mtlaccelerationstructureinstancedescriptor.md)
- [MTLAccelerationStructureUserIDInstanceDescriptor](metal/mtlaccelerationstructureuseridinstancedescriptor.md)
- [MTLAccelerationStructureMotionInstanceDescriptor](metal/mtlaccelerationstructuremotioninstancedescriptor.md)
- [MTLAccelerationStructureInstanceOptions](metal/mtlaccelerationstructureinstanceoptions.md)
- [MTL4IndirectInstanceAccelerationStructureDescriptor](metal/mtl4indirectinstanceaccelerationstructuredescriptor.md)
- [MTLIndirectInstanceAccelerationStructureDescriptor](metal/mtlindirectinstanceaccelerationstructuredescriptor.md)
- [MTLIndirectAccelerationStructureMotionInstanceDescriptor](metal/mtlindirectaccelerationstructuremotioninstancedescriptor.md)