I’m working on a project that needs me to be able to accurately identify of a given ARPlane is on the floor. I’ve looked at using XROrigins “Tracking Origin Mode”, however it is not clear from the documentation whether this affects the position of ARPlanes in game space, or only their Poses. If only the latter, is there any way to check the estimated height of a plane from the ARPlane component? I can’t seem to access the BoundedPlane or Pose of an ARPlane directly as the fields are protected.
The height of an ARPlane in Unity world space is the y-value of its Transform.position. This is the easiest way to accomplish reading the height. There are computations you can perform to get the session-space height, but all ARPlanes would be transformed by the same XROrigin, so the relative distances between each plane would be the same as if you just did this calculation in Unity world space.
On platforms that support plane classification (ARKit and Meta OpenXR), you can read the classification value, which is the recommended way to check whether a plane is the floor on platforms that support this. https://docs.unity3d.com/Packages/com.unity.xr.arfoundation@5.1/api/UnityEngine.XR.ARFoundation.ARPlane.classification.html#UnityEngine_XR_ARFoundation_ARPlane_classification