cameraNode children not rendered in 2.3.0 (regression from 0.9.4); HUD-style model no longer visible

[abdelhameedo]

Summary

I have a screen with a fixed arrow in the middle that rotates based on a compass heading (points to a GPS target). This worked for years on io.github.sceneview:arsceneview:0.9.4 by parenting the arrow under cameraNode.

Due to Google’s 16 KB page-size requirement I upgraded to io.github.sceneview:arsceneview:2.3.0. After upgrading, parenting to cameraNode no longer renders the arrow (invisible). If I add the same node to the scene root, it renders—but in world space (not HUD-fixed to the screen).

What changed

sceneView.addChildNode(arrow) → arrow is visible, but at a fixed world position.

sceneView.cameraNode.addChildNode(arrow) → arrow is not visible (it used to be visible and fixed to the screen center on 0.9.4).

I’m trying to confirm whether this is an intentional change in 2.x or a regression, and if there’s a supported way to attach a node to the camera for HUD-style rendering like before.

Repro steps

-Create a simple AR scene with ARSceneView.

-Load a small GLB (e.g., direction_arrow.glb) from assets/.

-Create a node for the model and try both:

-sceneView.addChildNode(node) (works, but world-anchored)

-sceneView.cameraNode.addChildNode(node) (does not render)

Minimal code

Old code (0.9.4) — worked (HUD fixed to camera)

`private fun addNodeToScene() {
lifecycleScope.launchWhenCreated {
arModelNode = ArModelNode(
placementMode = PlacementMode.INSTANT,
hitPosition = Position(0.0f, -0.1f, -0.3f),
followHitPosition = false,
instantAnchor = false
)

    arModelNode?.loadModelGlb(
        context = requireContext(),
        lifecycle = lifecycle,
        glbFileLocation = localModel,
        scaleToUnits = 0.5f,
        autoAnimate = true,
        onError = {}
    )
    arModelNode?.apply {
        parent = binding.sceneView.cameraNode
        localPosition = Position(0f, -0.1f, -0.3f)
        localScale = Position(0.3f, 0.3f, 0.3f)
        isScaleEditable = false
        isPositionEditable = false
        isRotationEditable = true
    }
}

}`

New code (2.3.0) — does not render when parented to cameraNode

`private fun addNodeToScene() {
viewLifecycleOwner.lifecycleScope.launchWhenCreated {
val engine = binding.sceneView.engine
val modelLoader = ModelLoader(engine, requireContext())

    val modelInstance = modelLoader.createModelInstance(localModel) ?: return@launchWhenCreated

    arModelNode = ModelNode(
        modelInstance = modelInstance,
        scaleToUnits = 0.5f,
        autoAnimate = true
    ).apply {
        // Expect HUD-like: attach to camera
        parent = binding.sceneView.cameraNode
        position = io.github.sceneview.math.Position(0f, -0.1f, -0.3f)
        scale = io.github.sceneview.math.Scale(0.3f)
        isScaleEditable = false
        isPositionEditable = false
        isRotationEditable = true
    }
}

}`

Expected behavior

When a node is a child of cameraNode, it should render fixed relative to the camera (HUD-style), as it did in 0.9.4.

Actual behavior

In 2.3.0, a child of cameraNode does not render (invisible). The same node added to the scene root renders correctly.