planeExtent
The estimated width, length, and y-axis rotation of the detected plane.
Declaration
var planeExtent: ARPlaneExtent { get }Discussion
When ARKit first detects a plane, the resulting ARPlaneAnchor object has a center value of (0,0,0), indicating that the translation portion of the anchor’s transform value locates the plane’s center point.
As the session runs, ARKit may determine that a previously detected plane anchor is part of a larger real-world surface, increasing the planeExtent width and height values. The plane’s new boundaries may not be symmetric around its initial position, so the center point changes relative to the anchor’s unchanged transform matrix.
Similarly, as the session runs, the framework may update the plane’s y-rotation to better fit its rectangular area in the environment. In iOS 15 and earlier, the framework rotates the plane anchor according to that angle. In iOS 16, the framework doesn’t rotate the anchor automatically and its transform matrix remains unchanged. Instead, the framework exposes the angle in rotationOnYAxis that you apply to any plane extent geometry in your app.