Camera lookAt position in Cartesian3

CesiumJS
1

Dear Cesium-Team,

May I have a question:
How to get or calculate the Coordinate (in form of Cartesian3) of the point on globe ground, that the camera is looking at?

best regards,

Zhihang

2

If you just want the point on the ground in the center of the screen, you can use camera.pickEllipsoid. In the below snippet, result will be a Cartesian3 if the function succeeds or undefined if the camera was pointing off of the earth.

var canvas = viewer.canvas;

var result = viewer.camera.pickEllipsoid(new Cesium.Cartesian2(canvas.clientHeight / 2, canvas.clientWidth / 2));

3

thank you very much. That is exactly what I need.

4

I tried this out and had success if I reversed the parameter order:

var result = viewer.camera.pickEllipsoid(new Cesium.Cartesian2( viewer.canvas.clientWidth / 2,viewer.canvas.clientHeight / 2));

cg = Cesium.Ellipsoid.WGS84.cartesianToCartographic(result);

console.log(" l ",cg.latitude180/Math.PI,cg.longitude180/Math.PI);

Copy/Pasting the console output into a geocoder then matches what is in the center of the screen.

Thanks for pointing out the function, this is very useful for matching say the pointer position to a point on the globe!