I'm currently toying around with the Cesium KML branch, tweaking and fixing a variety of issues I've come across and I'm hoping I could get a little bit of help with this latest problem (which seems like it's likely just a 1 line fix... but I just can't seem to figure it out).
I'm loading a png image blob ("processGroundOverlay") and the PNG has transparency associated with it... the current code:
var rectangle = new RectangleGraphics();
var icon = thePngImageBlob;
material = new ImageMaterialProperty();
material.image = new ConstantProperty(icon);
rectangle.material = material;
This results in the entire globe being wrapped in a layer of white, but the PNG contents are properly draped on their location.
I've also tried this without the image blob and loading the png from a url and I get the same results.
How do I set the RectangleGraphics to recognize the transparency in its material?