The lastest documentation for Plane Detection can be found in the documentation 


When using plane detection there are two modes available default and Scene Understanding (spatial meshing-based plane detection).



DefaultScene Understanding
Detection speed and first detectionNormalFast
False PositivesFew false positivesProne to false positives 
Plane accuracyHighHigh
Number of planesFewMany
Plane updates and movementStable with unlikely updatesDynamic with more plane updates
Plane orientation filterFilter options for horizontal and verticalNo filter options
Hit TestingAs expected against planeHit test against mesh


Unity

  • The option is available under Project Settings > XR Plug-in Management > OpenXR > Plane Detection.


Known issues with Scene Understanding

  • When using ARRaycast to test for a hit against an ARPlane generated by Scene Understanding the ray will be cast against the spatial mesh instead. The id of the ARRaycastHit result is the id of the mesh, not of the ARTrackable plane. 
  • Setting the detection mode in the AR Plane Manager is not possible at this moment. Every plane orientation will be tracked regardless of the chosen option. 


Unreal

  • Disabling Plane Detection in Unreal while Spatial Meshing is enabled will enable Scene Understanding in your map.
  • The option is available at Project Settings > Plugins > Snapdragon Spaces > Extensions
Scene Understanding activeDefault Plane Detection active



Known issues with Scene Understanding

  • Filtering for horizontal or vertical planes only is not possible when using Scene Understanding.