How to select cesium entity which is under another cesium entity?

CesiumJS
3

Hello @Gabby_Getz
please consider the use case,
considering below image from top view we see, red arrow and orange surface.
image

From front view it look’s something like below image.
image

If we notice the arrow is hidden behind the orange surface, in this case I am not able to either see or select the arrow.

Do you have any solution in mind, where I can see that arrow and pick the arrow in second case/image.

Few of the things that I had tries is by assigning the z-index, while creating the poly line it did not worked.

let arrowEntity = viewer.entities.add({
            description: 'Preview Arrow for Vertical Dragging.',
            polyline: {
                positions: positions,
                width: width,
                arcType: Cesium.ArcType.NONE,
                material: new Cesium.PolylineArrowMaterialProperty(
                    color
                ),
                **zIndex: 10**
            },
        });

Few other thing’s that I tired is by disabling the depth test.

        let arrowPrimitive = viewer.scene.primitives.add(
            new Cesium.Primitive({
                geometryInstances: new Cesium.GeometryInstance({
                    geometry: new Cesium.PolylineGeometry({
                        positions: positions,
                        width: width,
                        arcType: Cesium.ArcType.NONE
                    })
                }),

                appearance: new Cesium.PolylineMaterialAppearance({
                    material: new Cesium.Material({
                        fabric: {
                            type: "PolylineArrow",
                            uniforms: {
                                color: color,
                            }
                        }
                    }),
                    renderState: {
                        depthTest: {
                            enabled: false  // shut off depth test
                        }
                    }
                }),
                asynchronous: false   // block or not
            })
        );

The disabling the depth test solution does not work for dynamic poly line, dynamic meaning I am updating the poly line in here every time I select and drag the arrow.

Let me know your feedback on these solutions and also please share if you have any solution in mind for this problem.

some of the reference links that I found regarding this problem
[depthFailMaterial for dynamic polylines · Issue #5333 · CesiumGS/cesium · GitHub](https://Depth material for poly line)

[Disable Depth Test For Polylines and Polygons - #6 by Josh_S](https://Disabling the depth test for the polyline)

Thank you !!