---
title: indexBuffer
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtl4accelerationstructuremotiontrianglegeometrydescriptor/indexbuffer
---

# indexBuffer

Assigns an optional index buffer containing references to vertices in the vertex buffers you reference through the vertex buffers property.

## Declaration

```swift
var indexBuffer: MTL4BufferRange { get set }
```

## Discussion

Discussion You can set this property to 0, the default, to avoid specifying an index buffer. All keyframes share the same index buffer.