interact with 3D model inside SceneView without ArCore

Question

I'd like to load a 3D object on a Sceneview without Camera and ArCore. So I created a simple xml layout like so:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.google.ar.sceneform.SceneView
        android:id="@+id/scene"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

and loaded 3D object like so:

   private fun renderObject() {
    ModelRenderable.builder()
        .setSource(this, R.raw.andy)
        .build()
        .thenAccept {
            it?.let {
                node = Node().apply {
                    setParent(scene)
                    localPosition = Vector3(0f, 0f, -1f)
                    localScale = Vector3(3f, 3f, 3f)
                    name = "Andy"
                    renderable = it
                }

                scene.addChild(node)
            }
        }
        .exceptionally {
            val builder = AlertDialog.Builder(this)
            builder.setMessage(it.message)
                .setTitle("error!")
            val dialog = builder.create()
            dialog.show()
            return@exceptionally null
        }
}

and I get my 3D object as expected:

Now the problem is how to interact with this 3D object, rotate, zoom, and pick an element? I see that using ArCore there is TransformableNodes but how can I use it without ArCore?

Answer 1

There is a working example here in this repo: https://github.com/chnouman/SceneView

It uses a custom node (DragTransformableNode). The relevant snippet is in SceneViewActivity.kt.

    private fun addNodeToScene(model: ModelRenderable) {
        if (sceneView != null) {
            val transformationSystem = makeTransformationSystem()
            var dragTransformableNode = DragTransformableNode(1f, transformationSystem)
            dragTransformableNode?.renderable = model
            sceneView.getScene().addChild(dragTransformableNode)
            dragTransformableNode?.select()
            sceneView.getScene()
                .addOnPeekTouchListener { hitTestResult: HitTestResult?, motionEvent: MotionEvent? ->
                    transformationSystem.onTouch(
                        hitTestResult,
                        motionEvent
                    )
                }
        }
    }

I have forked this repo and am working on keyboard input support if anyone's interested in that.