---
title: roll
framework: vision
role: symbol
role_heading: Instance Property
path: vision/faceobservation/roll
---

# roll

The roll angle of a face.

## Declaration

```swift
let roll: Measurement<UnitAngle>
```

## Discussion

Discussion This value indicates the rotational angle of the face around the z-axis.

## See Also

### Inspecting an observation

- [RequestDescriptor](vision/requestdescriptor.md)
- [FaceObservation.Landmarks2D](vision/faceobservation/landmarks2d.md)
- [landmarks](vision/faceobservation/landmarks.md)
- [pitch](vision/faceobservation/pitch.md)
- [yaw](vision/faceobservation/yaw.md)