placeAnchor.kt

    private fun placeAnchor(hitResult: HitResult,
                            renderable: Renderable){
        val anchor = hitResult.createAnchor()
        placedAnchors.add(anchor)

        val anchorNode = AnchorNode(anchor).apply {
            isSmoothed = true
            setParent(arFragment!!.arSceneView.scene)
        }
        placedAnchorNodes.add(anchorNode)

        val node = TransformableNode(arFragment!!.transformationSystem)
            .apply{
                this.rotationController.isEnabled = false
                this.scaleController.isEnabled = false
                this.translationController.isEnabled = true
                this.renderable = renderable
                setParent(anchorNode)
            }

        arFragment!!.arSceneView.scene.addOnUpdateListener(this)
        arFragment!!.arSceneView.scene.addChild(anchorNode)
        node.select()
    }