Polyline dashes don't play nice with CallbackProperty

[emackey]

When using CallbackProperty, the polyline dashes are always shown horizontally, even if the line is mostly vertical in screen space.

Here's a demo. Try moving the camera around to see how the dashes behave at different orientations. The light blue line behaves the usual way, with the dashes facing the most prominent direction of the line. But the yellow line always cuts the dashes horizontally, regardless of the screen-space direction of the line.

/cc @AnneWoepse

var viewer = new Cesium.Viewer('cesiumContainer');

var redLine = viewer.entities.add({
    name : 'Yellow dashed line',
    polyline : {
        positions : new Cesium.CallbackProperty(() => {
        return Cesium.Cartesian3.fromDegreesArrayHeights([-95, 50, 250000,
                                                        -95, 30, 250000]);
        }, false),
        width : 8,
        material : new Cesium.PolylineDashMaterialProperty({
            color: Cesium.Color.YELLOW
        })
    }
});

var blueLine = viewer.entities.add({
    name : 'Blue dashed line',
    polyline : {
        positions : Cesium.Cartesian3.fromDegreesArrayHeights([-98, 50, 250000,
                                                        -98, 30, 250000]),
        width : 8,
        material : new Cesium.PolylineDashMaterialProperty({
            color: Cesium.Color.LIGHTSKYBLUE
        })
    }
});


viewer.zoomTo(viewer.entities);

[hpinkos]

Could no longer reproduce