GroundPrimitive polygon disappears when zooming out

[hpinkos]

Reported on the forum https://groups.google.com/forum/?hl=en#!topic/cesium-dev/-QMn8KdVEhw

var viewer = new Cesium.Viewer('cesiumContainer');
var cesiumTerrainProviderMeshes = new Cesium.CesiumTerrainProvider({
    url : 'https://assets.agi.com/stk-terrain/world',
    requestWaterMask : true,
    requestVertexNormals : true
});
viewer.terrainProvider = cesiumTerrainProviderMeshes;


function drawPolygon() {
    var e = viewer.entities.add({
                polygon : {
                    hierarchy : {
                        positions: [new Cesium.Cartesian3.fromDegrees(-80.52240492379808,26.07276605035512),
                                    new Cesium.Cartesian3.fromDegrees(-80.38142436812922,26.072221561466225),
                                    new Cesium.Cartesian3.fromDegrees(-80.3813686168645,26.08386721144594),
                                    new Cesium.Cartesian3.fromDegrees(-80.52234917227406,26.084411700334833)]
                    },
                    material : Cesium.Color.BLUE.withAlpha(0.5)
                }
            });


    viewer.zoomTo(e);}


drawPolygon();

[bagnell]

This is either a duplicate of or related to #4161.

[hpinkos]

Good call @bagnell, looks like the same problem