Retrieving the height of a polygon in CesiumJS

CesiumJS
1

Hello Everyone
I am trying to display the heights of polygons that I created using CesiumJS when I click on them. I am able to get the coordinates, but I am having trouble getting the height information. Thank you in advance for your support.

2

Hello,
Would you please provide a working sandcastle of what you have now?

What do you mean when you say “coordinates”? Do you mean that you can get a Cartesian3?

To get height above the WGS84 ellipsoid, you can convert a Cartesian3 to a Cartographic and take the height of the result.

const height = Cartographic.fromCartesian(coordinate).height;
3

Hello @Erixen_Cruz!
Firstly , thanks for your reply, I can share with you an example of a function that I have written to perform this task below:

var handler = new Cesium.ScreenSpaceEventHandler(viewer.canvas);
        handler.setInputAction(function(click) {
            var pickedObject = viewer.scene.pick(click.position);
            if (Cesium.defined(pickedObject) && pickedObject.id instanceof Cesium.Entity) {
                var cartesian = viewer.scene.globe.pick(viewer.camera.getPickRay(click.position), viewer.scene);
                if (Cesium.defined(cartesian)) {
                    var cartographic = Cesium.Cartographic.fromCartesian(cartesian);
                    var longitude1 = Cesium.Math.toDegrees(cartographic.longitude);
                    var latitude1 = Cesium.Math.toDegrees(cartographic.latitude);
                    var height1 = cartographic.height;
                    // var height1 = Cesium.Ellipsoid.WGS84.geoidHeight(longitude1, latitude1); // also i tried this method but returned null 
                    console.log('longitude1, latitude1, height1);
                }
            }
        }, Cesium.ScreenSpaceEventType.LEFT_CLICK);

While I am able to successfully retrieve the latitude and longitude information, I am encountering an issue where the output for the height is returning numerical values rather than the correct polygon height.

I can also provide you with an example of the output below:

longitude :26.35883648129588 latitude: 40.09446384834312 height: 39.57011483825242

but the polygon height value is 152.5 at these coordinates

true output: longitude :26.35883648129588 latitude: 40.09446384834312 height: 152.5

I would like to express my gratitude in advance for your assistance.

4

Maybe you want pickPosition instead of pick. See this sandcastle Cesium Sandcastle. May be able to help you better with a working sandcastle demonstrating what you are doing.