title: Cesium: Entity (point) is not shown in 3D mode?
body: <p>I've added an entity:</p>
  
  <pre><code>var debris = cesiumViewer.entities.add({
    position : { 
      value : Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883, 1000) ,
      referenceFrame : Cesium.ReferenceFrame.FIXED 
    },
    point : {
      color : Cesium.Color.YELLOW,
      pixelSize : 6
    }
  });
  </code></pre>
  
  <p>The point is shown in 2D and Columbus mode, but hidden in 3D mode. Also, in Columbus mode it looks like the altitude iz 0.</p>
  
  <p>Added also <code>cesiumViewer.scene.globe.depthTestAgainstTerrain = true;</code></p>
  
  <p>Where is the issue?</p>