GraphicsOverlay.sceneProperties ignores LayerSceneProperties when added to multiple GraphicsOverlays

Question

Hello,

There seems to be a quirk when using the same LayerSceneProperties definition (variable) for multiple GraphicsOverlay.

If you define a single variable

let sceneProps = LayerSceneProperties(surfacePlacement: SurfacePlacement.relative)

and then configure all the GraphicsOverlay to use it

let o1 = GraphicsOverlay()
o1.sceneProperties = sceneProps
o1.addGraphics(g1)

let o2 = GraphicsOverlay()
o2.sceneProperties = sceneProps
o2.addGraphics(g2)

let o3 = GraphicsOverlay()
o3.sceneProperties = sceneProps
o3.addGraphics(g3)

it does not seem to apply it to the other layers, and you get the following result:

However, if you don't use a variable, and set it directly for each layer, it seems to work:

let o1 = GraphicsOverlay()
o1.sceneProperties = LayerSceneProperties(surfacePlacement: SurfacePlacement.relative)
o1.addGraphics(g1)

let o2 = GraphicsOverlay()
o2.sceneProperties = LayerSceneProperties(surfacePlacement: SurfacePlacement.relative)
o2.addGraphics(g2)

let o3 = GraphicsOverlay()
o3.sceneProperties = LayerSceneProperties(surfacePlacement: SurfacePlacement.relative)
o3.addGraphics(g3)

See image:

Full code to reproduce attached as .txt files.

(basically this)

private class Model: ObservableObject {
    let scene = {
        let x = ArcGIS.Scene(basemapStyle: .arcGISTopographic)
        x.initialViewpoint = Viewpoint(
            latitude: .nan,
            longitude: .nan,
            scale: .nan,
            camera: Camera(
                latitude: 33.997037,
                longitude: -118.4970704,
                altitude: 231,
                heading: 357,
                pitch: 80,
                roll: 0
            )
        )

return x
    }

let graphicsOverlays: [GraphicsOverlay] = {
        let red = SimpleMarkerSceneSymbol(style: .sphere, color: .red, height: 50, width: 50, depth: 50, anchorPosition: .center)
        let yellow = SimpleMarkerSceneSymbol(style: .sphere, color: .yellow, height: 50, width: 50, depth: 50, anchorPosition: .center)
        let blue = SimpleMarkerSceneSymbol(style: .sphere, color: .blue, height: 50, width: 50, depth: 50, anchorPosition: .center)

let p1 = [
            Point(x: -118.4978, y: 34.0086, z: 110, spatialReference: .wgs84),
            Point(x: -118.4968, y: 34.0096, z: 140, spatialReference: .wgs84),
            Point(x: -118.4958, y: 34.0106, z: 170, spatialReference: .wgs84),
        ]
        let g1 = p1.map { p in
            return Graphic(geometry: p, symbol: red)
        }

let p2 = [
            Point(x: -118.4977, y: 34.0056, z: 120, spatialReference: .wgs84),
            Point(x: -118.4978, y: 34.0066, z: 180, spatialReference: .wgs84),
            Point(x: -118.4979, y: 34.0076, z: 220, spatialReference: .wgs84),
        ]
        let g2 = p2.map { p in
            return Graphic(geometry: p, symbol: yellow)
        }

let p3 = [
            Point(x: -118.4957, y: 34.0056, z: 100, spatialReference: .wgs84),
            Point(x: -118.4958, y: 34.0066, z: 150, spatialReference: .wgs84),
            Point(x: -118.4959, y: 34.0076, z: 200, spatialReference: .wgs84),
        ]
        let g3 = p3.map { p in
            return Graphic(geometry: p, symbol: blue)
        }

let o1 = GraphicsOverlay()
        o1.sceneProperties = LayerSceneProperties(surfacePlacement: SurfacePlacement.relative)
        o1.addGraphics(g1)

let o2 = GraphicsOverlay()
        o2.sceneProperties = LayerSceneProperties(surfacePlacement: SurfacePlacement.relative)
        o2.addGraphics(g2)

let o3 = GraphicsOverlay()
        o3.sceneProperties = LayerSceneProperties(surfacePlacement: SurfacePlacement.relative)
        o3.addGraphics(g3)

return [
            o1,
            o2,
            o3,
        ]
    }()
}

struct DisplaySceneView: View {
    /// A scene with imagery basemap style and a tiled elevation source.

@StateObject private var model = Model()

var body: some View {
        // Creates a scene view with the scene.
        SceneView(scene: model.scene(), graphicsOverlays: model.graphicsOverlays)
    }
}

This example is using arcgis-maps-sdk-swift 300.1, on iOS 26.5.

Not sure if this is intentional or not. Just leaving it here, if others can't figure out why the other layers do not respect `z` and place all the items at the bottom of z.

scene-props-ok.txt

scene-props-broken.txt

Ting · Accepted Answer

Thanks for reporting this issue.

The recommended approach is to configure the GraphicsOverlay.sceneProperties object directly, rather than assigning a new instance to it. That way, each graphics overlay maintains its own scene properties object, and there won't be conflicts between them.

I'll discuss with team to see if this is expected or not, and maybe improve the error reporting on that.