map3D.when(function(){
            // Retrieve FeatureLayer from WebScene
            var featureLayer3D = map3D.layers.find(function(layer){
              return layer.title === "Env 09092018";
            });

            // Define elevationInfo and set it on the layer
            var currentElevationInfo = {
              mode: "absolute-height",
              offset: -20,
              unit: "meters"
            };

            featureLayer3D.elevationInfo = currentElevationInfo;
        });