---
title: instanceDescriptorType
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtl4indirectinstanceaccelerationstructuredescriptor/instancedescriptortype
---

# instanceDescriptorType

Controls the type of instance descriptor that the instance descriptor buffer references.

## Declaration

```swift
var instanceDescriptorType: MTLAccelerationStructureInstanceDescriptorType { get set }
```

## Discussion

Discussion This value determines the layout Metal expects for the structs the instance descriptor buffer contains. Defaults to MTLAccelerationStructureInstanceDescriptorTypeIndirect. Valid values for this property are MTLAccelerationStructureInstanceDescriptorTypeIndirect or MTLAccelerationStructureInstanceDescriptorTypeIndirectMotion.