<!--
{
  "availability" : [
    "iOS: 27.0.0 -",
    "iPadOS: 27.0.0 -",
    "tvOS: 27.0.0 -",
    "visionOS: 27.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "RealityKit",
  "identifier" : "/documentation/RealityKit/LowLevelMeshResource/Descriptor-swift.struct/instanceCapacity",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "RealityKit"
    ],
    "preciseIdentifier" : "s:19RealityCoreRenderer20LowLevelMeshResourceC10DescriptorV16instanceCapacitySivp"
  },
  "title" : "instanceCapacity"
}
-->

# instanceCapacity

The maximum number of instances the mesh supports when using per-instance vertex data.

```
var instanceCapacity: Int { get set }
```

## Discussion

Set this to the maximum number of instances you intend to draw when any
`Layout` in `vertexLayouts` uses a `stepFunction` of `.perInstance`. Defaults to `0`.

Corresponds to `MTLVertexDescriptor`’s per-instance buffer layout capacity.

---

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)