KML - problem with GroundOverlay icon

hi,
I'm using Cesium 1.19 and I'm trying to display KML file that includes GroundOverlay icon with transparent png file.

It looks like that Cesium 1.19 doesn't support transparent png file - instead of transparency I see black background.

What is more interesting I'm migrating from Cesium 1.14 where transparency was supported correctly.

You can find my kml and png file here: https://goo.gl/1dmyUl

png is displayed in north-west of Poland

my js code:

var url = "test.kml";
var dataSources = viewer.dataSources;

dataSources.add(
                kmlDataSource.load(url, {
                 camera: viewer.scene.camera,
                 canvas: viewer.scene.canvas
                })
            );

Hello,

This is a known issue, reported here: https://github.com/AnalyticalGraphicsInc/cesium/issues/3459

The best work around we have right now is to set the alpha value for your image to something very close to 1, like alpha: 0.99

Best,

Hannah

Hello,

This issue has been fixed and will be included in the Cesium 1.20 release, available on April 1st. Images loaded from KML should automatically have the transparent property applied correctly.

Best,

Hannah