Display 3d polygon layer at plane (true elevation)

Hi there,

I have a 3d ESRI polygon layer (geojson). I would like to display this in Cesium at it’s true elevation (not clamped to ground). The effect I am looking for is to model floo plain data in 3d.

Here is the code I have started with:

		const polygonLayerName = "Flood Plain";
        const polygonLayerURL = "https://services.arcgis.com/bDAhvQYMG4WL8O5o/arcgis/rest/services/Charleston_SLR_2080_WaterSurface3D/FeatureServer/64";
        url: polygonLayerURL,
    }).then((response) => {

        const data = Cesium.GeoJsonDataSource.load(response,{


Is this possible?

I would like to see the water level clipping 3d features.

Thanks in advance,


PS The polygons seems to “float” a specific distance above the Google Maps 3d tiles surface:

Solved this issue by changing z data values in the JSON data. Not an ideal fix but perfectly do-able.