Tap on Point?

[rongguodong]

We have BaseArFragment.OnTapArPlaneListener now, but missing BaseArFragment.OnTapArPointListener. So it is not easy to use Sceneform to reproduce the same app as hello_ar_java example.

Can you add a BaseArFragment.OnTapArPointListener, or more general BaseArFragment.OnTapArTrackableListener?

[claywilkinson]

Thanks for the feedback! I'll pass it along as an enhancement request (it sounds like a great idea).

In the mean time, you can override the processing via setOnPeekTouchListener()

Declare your own gesture detector in the activity:

    private GestureDetector trackableGestureDetector;

In onCreate(), install your own onPeekTouchListener. This is called for each touch to possibly handle interactions with the TransformableNodes.

    arFragment.getArSceneView().getScene().setOnPeekTouchListener(this::handleOnTouch);
    this.trackableGestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener() {
            public boolean onSingleTapUp(MotionEvent e) {
               onSingleTap(e);
                return true;
            }

        public boolean onDown(MotionEvent e) {
                return true;
            }
        });

Then implement handleOnTouch:

    private void handleOnTouch(HitTestResult hitTestResult, MotionEvent motionEvent) {
        // First call ArFragment's listener to handle TransformableNodes.
        arFragment.onPeekTouch(hitTestResult, motionEvent);

        // Check for touching a Sceneform node
        if (hitTestResult.getNode() != null) {
           return;
        }

        // Otherwise call gesture detector.
        trackableGestureDetector.onTouchEvent(motionEvent);
    }

Finally implement the onSingleTap() method called by the gesture dectector. In this method, call ARCore's frame.hittest() to get the hits on trackables.

    private void onSingleTap(MotionEvent motionEvent) {
        Frame frame = arFragment.getArSceneView().getArFrame();
        if (frame != null && motionEvent != null && frame.getCamera().getTrackingState() == TrackingState.TRACKING) {
            for (HitResult hit : frame.hitTest(motionEvent)) {
                Trackable trackable = hit.getTrackable();
                if (trackable instanceof Plane && ((Plane)trackable).isPoseInPolygon(hit.getHitPose())) {
                    Plane plane = (Plane)trackable;

                    // Handle plane hits.
                    break;
                } else if (trackable instanceof Point ) {
                    // Handle point hits
                    Point point = (Point) trackable;

                } else if (trackable instanceof AugmentedImage) {
                    // Handle image hits.
                    AugmentedImage image = (AugmentedImage) trackable;
                }
            }
        }
    }