<!--
{
  "availability" : [
    "iOS: 15.0.0 -",
    "iPadOS: 15.0.0 -",
    "macCatalyst: 15.0.0 -",
    "macOS: 12.0.0 -",
    "tvOS: 16.0.0 -",
    "visionOS: 1.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "Metal",
  "identifier" : "/documentation/Metal/MTLAccelerationStructureInstanceDescriptorType",
  "metadataVersion" : "0.1.0",
  "role" : "Enumeration",
  "symbol" : {
    "kind" : "Enumeration",
    "modules" : [
      "Metal"
    ],
    "preciseIdentifier" : "c:@E@MTLAccelerationStructureInstanceDescriptorType"
  },
  "title" : "MTLAccelerationStructureInstanceDescriptorType"
}
-->

# MTLAccelerationStructureInstanceDescriptorType

Options for specifying different kinds of instance types.

```
enum MTLAccelerationStructureInstanceDescriptorType
```

## Topics

### Specifying the instance descriptor type

[`MTLAccelerationStructureInstanceDescriptorType.default`](/documentation/Metal/MTLAccelerationStructureInstanceDescriptorType/default)

An option specifying that the instance uses the default characteristics.

[`MTLAccelerationStructureInstanceDescriptorType.userID`](/documentation/Metal/MTLAccelerationStructureInstanceDescriptorType/userID)

An option specifying that the instance contains a user identifier.

[`MTLAccelerationStructureInstanceDescriptorType.motion`](/documentation/Metal/MTLAccelerationStructureInstanceDescriptorType/motion)

An option specifying that the instance contains motion data.

[`MTLAccelerationStructureInstanceDescriptorType.indirect`](/documentation/Metal/MTLAccelerationStructureInstanceDescriptorType/indirect)

An option that enables an instance descriptor memory layout the GPU can populate.

[`MTLAccelerationStructureInstanceDescriptorType.indirectMotion`](/documentation/Metal/MTLAccelerationStructureInstanceDescriptorType/indirectMotion)

An option specifying that the instance contains motion data, and enables using an instance descriptor memory layout that the GPU can populate.


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)