MainActivity.kt

/**
     * Used to load model and set it on ArScene where a user Taps
     */
    private fun setModelOnUi(hitResult: HitResult) {
        loadModel(R.raw.model) { modelRenderable ->
            //Used to get anchor point on scene where user tapped
            val anchor = hitResult.createAnchor()
            //Created an anchor node to attach the anchor with its parent
            val anchorNode = AnchorNode(anchor)
            //Added arSceneView as parent to the anchorNode. So our anchors will bind to arSceneView.
            anchorNode.setParent(arFragment.arSceneView.scene)

            //TransformableNode for out model. So that it can be rotated, scaled etc using gestures
            val transformableNode = TransformableNode(arFragment.transformationSystem)
            //Assigned anchorNode as parent so that our model stays at the position where user taps
            transformableNode.setParent(anchorNode)
            //Assigned the resulted model received from loadModel method to transformableNode
            transformableNode.renderable = modelRenderable
            //Sets this node as selected node by default
            transformableNode.select()
        }
    }