3D模式Cesium屏幕坐标转世界坐标

var pick1= new Cesium.Cartesian2(0,0);
var cartesian = viewer.scene.globe.pick(viewer.camera.getPickRay(pick1),viewer.scene);

2D模式Cesium屏幕坐标转世界坐标

var pick= new Cesium.Cartesian2(0,0);
var cartesian = viewer.camera.pickEllipsoid(pick, viewer.scene.globe.ellipsoid);