---
title: VNDetectTrajectoriesRequest
framework: vision
role: symbol
role_heading: Class
path: vision/vndetecttrajectoriesrequest
---

# VNDetectTrajectoriesRequest

A request that detects the trajectories of shapes moving along a parabolic path.

## Declaration

```swift
class VNDetectTrajectoriesRequest
```

## Mentioned in

Identifying Trajectories in Video

## Overview

Overview After the request detects a trajectory, it produces an observation that contains the shape’s detected points and an equation describing the parabola.

## Topics

### Creating a Request

- [init(frameAnalysisSpacing:trajectoryLength:completionHandler:)](vision/vndetecttrajectoriesrequest/init(frameanalysisspacing:trajectorylength:completionhandler:).md)

### Configuring the Request

- [targetFrameTime](vision/vndetecttrajectoriesrequest/targetframetime.md)
- [trajectoryLength](vision/vndetecttrajectoriesrequest/trajectorylength.md)
- [objectMinimumNormalizedRadius](vision/vndetecttrajectoriesrequest/objectminimumnormalizedradius.md)
- [objectMaximumNormalizedRadius](vision/vndetecttrajectoriesrequest/objectmaximumnormalizedradius.md)
- [minimumObjectSize](vision/vndetecttrajectoriesrequest/minimumobjectsize.md)
- [maximumObjectSize](vision/vndetecttrajectoriesrequest/maximumobjectsize.md)

### Inspecting the Results

- [results](vision/vndetecttrajectoriesrequest/results.md)
- [VNTrajectoryObservation](vision/vntrajectoryobservation.md)

### Identifying Request Revisions

- [VNDetectTrajectoriesRequestRevision1](vision/vndetecttrajectoriesrequestrevision1.md)

## Relationships

### Inherits From

- [VNStatefulRequest](vision/vnstatefulrequest.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCopying](foundation/nscopying.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Trajectory detection

- [Identifying Trajectories in Video](vision/identifying-trajectories-in-video.md)
- [Detecting moving objects in a video](vision/detecting-moving-objects-in-a-video.md)