ARCore: Get get 2d co-ordinate from an anchor or pose

Question

So this is the code I'm using to get all the feature planes.

                            while (planeIterator.hasNext()){
                                    Plane plane =  planeIterator.next();
        
                                    if(plane.getTrackingState() == TrackingState.TRACKING && 
    (plane.getType() == Plane.Type.VERTICAL||plane.getType() == Plane.Type.HORIZONTAL_UPWARD_FACING)){
        
                                    Iterator<Anchor> anchors =  frame.getUpdatedAnchors().iterator();
                                   Anchor  newAnchor = plane.createAnchor(plane.getCenterPose());
                                 }
                             }

It's not clear from the documentation how to get the 3d world coordinates from the anchor. If I could get that 3d world coordinate, I could convert to 2D using

ArFragment.getArSceneView().getScene().getCamera().worldToScreenPoint()

But how do you get the 3D world to co-ordinate from the newAnchor ?

Answer 1

I think you are asking for the pose of the anchor - this is available from the getPose() method:

public Pose getPose ()

Returns the pose of the anchor in the world coordinate space.

Pose is defined as the mapping of an object for its local co-ordinates, ie if you just look at the object itself, into the world co-ordinates. It is usually described as a rotation followed by a translation. The rotation gets the object pointing the right way, or orientated correctly, and then the translation moves it to the correct place in the world co-ordinates.

If you look at the Pose class you can query whatever information you need for your use case from it.

One quick note - I am guessing you are aware but Sceneform is no deprecated, or more accurately open sourced and then archived - see here: https://developers.google.com/sceneform/develop .