trackMidPoint.js

const TG = require("TouchGestures");
const Scene = require("Scene");
const R = require("Reactive");
const DMw = require("DeviceMotion").worldTransform;
const CameraInfo = require("CameraInfo");
const Time = require("Time");

/*
Your scene should have a planeTracker and a nullObject as it's child
Everything under the nullObject (called nullPositioner in this case) will be affected and be modified with the plane tracker values
*/

(async function initPlaneTracker() {
    let nullPositioner = await Scene.root.findFirst("nullPositioner"); // CHANGE to the name of your parent null object in the scene
    let trackerPlane = await Scene.root.findFirst("planeTracker0");  // CHANGE to the name of your plane tracker in the scene

    new Promise(resolve => {Time.setTimeout(()=>{resolve()}, 3000)}).then(()=>{
        R.monitorMany({'X': DMw.x, 'Y': DMw.y, 'Z': DMw.z, 'rtx': DMw.rotationX, 'rty': DMw.rotationY, 'rtz': DMw.rotationZ})
        .subscribe(()=>{
            trackerPlane.trackPoint(R.div(CameraInfo.previewSize.x, 2).pinLastValue(), R.div(CameraInfo.previewSize.y, 2).pinLastValue());

            nullPositioner.transform.scaleX = R.div(1, trackerPlane.worldTransform.scaleX);
            nullPositioner.transform.scaleY = R.div(1, trackerPlane.worldTransform.scaleY);
            nullPositioner.transform.scaleZ = R.div(1, trackerPlane.worldTransform.scaleZ);
        });
    });
})();