So I'm trying to do a thing where you double click on the map and some stuff is kicked off using that position. I seem to be having some trouble getting it to work though. I basically cribbed from the Picking example in the Sandcastle like so. Immediately after creating the Cesium viewer:
var scene = this.viewer.scene;
var ellipsoid = scene.globe.ellipsoid;
var handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
var cartesian = scene.camera.pickEllipsoid(movement.startPosition,ellipsoid);
And when I try this code, pickEllipsoid throws an exception because it says it expects a windowPosition. This code is almost exactly the same as the Sandcastle example, so I don't know why it's balking at my version and not that. Am I missing something?