---
title: DetectTrajectoriesRequest
framework: vision
role: symbol
role_heading: Class
path: vision/detecttrajectoriesrequest
---

# DetectTrajectoriesRequest

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

## Declaration

```swift
final class DetectTrajectoriesRequest
```

## Overview

Overview After the request detects a trajectory, it produces a collection of TrajectoryObservation objects that contain the shape’s detected points and an equation describing the parabola.

## Topics

### Creating a request

- [init(trajectoryLength:_:frameAnalysisSpacing:)](vision/detecttrajectoriesrequest/init(trajectorylength:_:frameanalysisspacing:).md)

### Performing a request

- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-80bya.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-3f3f1.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-qxxx.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-xspx.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-3hddl.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-85ex1.md)

### Understanding the result

- [TrajectoryObservation](vision/trajectoryobservation.md)

### Configuring a request

- [objectMaximumNormalizedRadius](vision/detecttrajectoriesrequest/objectmaximumnormalizedradius.md)
- [objectMinimumNormalizedRadius](vision/detecttrajectoriesrequest/objectminimumnormalizedradius.md)
- [targetFrameTime](vision/detecttrajectoriesrequest/targetframetime.md)
- [trajectoryLength](vision/detecttrajectoriesrequest/trajectorylength.md)

### Getting the revision

- [revision](vision/detecttrajectoriesrequest/revision-swift.property.md)
- [supportedRevisions](vision/detecttrajectoriesrequest/supportedrevisions.md)
- [DetectTrajectoriesRequest.Revision](vision/detecttrajectoriesrequest/revision-swift.enum.md)

## Relationships

### Conforms To

- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [ImageProcessingRequest](vision/imageprocessingrequest.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)
- [StatefulRequest](vision/statefulrequest.md)
- [VisionRequest](vision/visionrequest.md)

## See Also

### Motion and object tracking

- [TrackObjectRequest](vision/trackobjectrequest.md)
- [TrackOpticalFlowRequest](vision/trackopticalflowrequest.md)
- [TrackRectangleRequest](vision/trackrectanglerequest.md)