---
title: "extrinsicMatrix(from:to:)"
framework: avfoundation
role: symbol
role_heading: Type Method
path: "avfoundation/avcapturedevice/extrinsicmatrix(from:to:)"
---

# extrinsicMatrix(from:to:)

Returns the relative extrinsic matrix from one capture device to another.

## Declaration

```swift
class func extrinsicMatrix(from fromDevice: AVCaptureDevice, to toDevice: AVCaptureDevice) -> Data?
```

## Parameters

- `fromDevice`: The capture device that represents the source camera.
- `toDevice`: The capture device that represents the destination camera.

## Return Value

Return Value A Data containing a matrix_float4x3 matrix, which is a column major with 3 rows and 4 columns.

## Discussion

Discussion The extrinsic matrix consists of a unitless 3x3 rotation matrix (R) on the left and a translation (t) 3x1 column vector on the right, whose units are millimeters. The matrix expresses the destination camera’s extrinsics relative to the source camera. If X_from is a 3D point in the source camera’s coordinate system, you project it into the destination camera’s coordinate system with X_to = [R | t] * X_from. Only physical cameras for which factory calibrations exist provide an extrinsic matrix. Virtual device cameras return nil. important: If you enable video stabilization by setting a preferredVideoStabilizationMode value, the pixels in stabilized video frames no longer match the relative extrinsic matrix from one device to another due to warping. Disable video stabilization if you’re using the extrinsic matrix and camera intrinsics.