Cesium How To 'drape' A Polygon Or Line Onto Terrain Surface

So, I'm using cesium and I want to add a polygon or line to represent a property boundary on a terrain surface. My polygon works fine on the flat/Ellipsoid surface, unfortunately h

Solution 1:

As of version 1.13 cesium now supports GroundPrimitives. They will drape over terrain.

It looks like this: http://cesiumjs.org/images/2015/09-01/groundPrimitives.gif

This the example Cesium gives:

var rectangleInstance = new Cesium.GeometryInstance({
  geometry : new Cesium.RectangleGeometry({
    rectangle : Cesium.Rectangle.fromDegrees(-140.0, 30.0, -100.0, 40.0)
  }),
  id : 'rectangle',
  attributes : {
    color : new Cesium.ColorGeometryInstanceAttribute(0.0, 1.0, 1.0, 0.5)
  }
});
scene.primitives.add(new Cesium.GroundPrimitive({
  geometryInstance : rectangleInstance
}));

Solution 2:

Cesium does not support vector data on terrain yet. It is being actively worked on and most features should start to appear in Cesium 1.10 which will be out on June 1st. Anything that doesn't make that release should be in 1.11 on July 1st.

For Polygons specifically, you can follow along with the GitHub pull request: https://github.com/AnalyticalGraphicsInc/cesium/pull/2618

For Billboards and Labels, check out: https://github.com/AnalyticalGraphicsInc/cesium/pull/2653

Polylines haven't been started yet but will be as soon as the above two are finished.