Plane detection

Plane detection on the Meta OpenXR platform works similarly to other AR platforms, but there are some platform-specific nuances to consider when developing your app. The following sections explain each of these platform-specific cases.

Room setup

Plane detection on Meta Quest devices requires that you run Room Setup on your Meta Quest device before any planes can be detected.

Unlike other AR platforms, Meta OpenXR does not dynamically discover planes at runtime. Instead, the Unity OpenXR: Meta queries the device's Room Setup data and returns all plane components that are stored in its Scene Model. Some entities in the Scene Model, such as Tables or Couches, include planes, while others do not.

Important

If Room Setup is not complete, AR Foundation cannot detect any planes. If your app requires planes, you can use scene capture to prompt the user to complete Room Setup.

Trackable ID

Unlike other AR platforms, the trackableId property of any ARPlane from the Meta OpenXR platform persists across multiple sessions in the same room setup. This allows you to, for instance, save the trackableId of a user's table to persist a virtual centerpiece on the table each time the user runs your app.

Plane alignment

Also unique to the Meta OpenXR platform is the planeAlignmentThreshold property, which determines the threshold for PlaneAlignment categorization. Plane alignment is calculated by taking each component of the plane's normal vector and finding their difference from 0. If the difference is less than the planeAlignmentThreshold, then the MetaOpenXRPlaneSubsystem will categorize the plane depending on which of the normal vector's components are within the threshold. The x and z components are both checked for horizontal planes while the y component is checked for vertical planes.

Plane classification

This package maps Meta's native semantic label component to AR Foundation's PlaneClassification. Natively, Meta supports multiple classifications per plane, but ARPlane.classification will only contain the first label, or None if the label cannot be determined.

Refer to the table below to understand the mapping between Meta's semantic labels and AR Foundation's classifications:

Meta Label	AR Foundation Label
DESK	Table
COUCH	Seat
FLOOR	Floor
CEILING	Ceiling
WALL_FACE	Wall
DOOR_FRAME	Door
WINDOW_FRAME	Window
SCREEN	Other
LAMP	Other
PLANT	Other
STORAGE	Other
BED	Other
OTHER	Other