---
title: "init(completionHandler:)"
framework: vision
role: symbol
role_heading: Initializer
path: "vision/vntrackopticalflowrequest/init(completionhandler:)"
---

# init(completionHandler:)

Creates a new request that tracks the optical from one image to another, with a system callback on completion.

## Declaration

```swift
init(completionHandler: VNRequestCompletionHandler? = nil)
```

## Parameters

- `completionHandler`: The callback the system invokes when it completes the request.

## See Also

### Creating an Optical Flow

- [init()](vision/vntrackopticalflowrequest/init().md)