---
title: "setBuffer(_:bufferOffset:elementCount:at:)"
framework: realitykit
role: symbol
role_heading: Instance Method
platforms: [iOS 27.0+, iPadOS 27.0+, macOS 27.0+, tvOS 27.0+, visionOS 27.0+]
path: "realitykit/computegraphcomponent/setbuffer(_:bufferoffset:elementcount:at:)"
---

# setBuffer(_:bufferOffset:elementCount:at:)

Binds a Metal buffer to a parameter.

## Declaration

```swift
mutating func setBuffer(_ buffer: (any MTLBuffer)?, bufferOffset: Int = 0, elementCount: Int? = nil, at index: Int)
```

## Parameters

- `buffer`: The MTLBuffer to bind.
- `bufferOffset`: Byte offset into buffer. Defaults to 0.
- `elementCount`: Number of elements in the buffer, for buffers with variable capacity.
- `at`: Index into the device buffers table.