huge area with alpha transparency

1. A concise explanation of the problem you're experiencing.

Earth opacity seems to be ignored rendering a huge area (polygon) filled with a color and with alpha lower than 1.

one of the vertex of this triangle, should be invisible if the Earth is "solid".

2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.

var viewer = new Cesium.Viewer('cesiumContainer',{
  animation: false,
  orderIndependentTranslucency: false,
  baseLayerPicker: false,
  timeline: false,
  infoBox: false,
  homeButton: false,
  geocoder: false,
  sceneModePicker: false,
  fullscreenButton: false

var tri = viewer.entities.add({
  polygon : {
    hierarchy : new Cesium.PolygonHierarchy(
      Cesium.Cartesian3.fromDegreesArray([10, 50, -150, 20, 20, -34])
    material : Cesium.Color.fromCssColorString('#21B421').withAlpha(0.1),
    arcType : Cesium.ArcType.RHUMB

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

i need to show some large areas of the planet
it's like "if you put some antennas in this points, the coverage is <polygon>"

4. The Cesium version you're using, your operating system and browser.

i'm using

I think this might be a bug with translucency/depth testing. I’ve opened a bug report here:

Thanks for reporting this!

tnx omar