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;