pickPosition doesn't pick ellipsoid in 2D and CV

[hpinkos]

In 3D, pickPosition will return a position when hovering over the globe. In 2D and CV, it's the result is always undefined

var viewer = new Cesium.Viewer('cesiumContainer', {
    sceneMode: Cesium.SceneMode.SCENE2D
});

// Mouse over the globe to see the cartographic position
var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
handler.setInputAction(function(movement) {
    var cartesian = viewer.scene.pickPosition(movement.endPosition);
    if (!Cesium.defined(cartesian)) {
      console.log('undefined');
    }
}, Cesium.ScreenSpaceEventType.MOUSE_MOVE);

[thw0rted]

I came to report that 2D picking isn't working for WMS (GetFeatureInfo), and I'm wondering if it's a subset of this issue. Demo: go to the WMS Sandcastle, select a point, watch the info load.
Now, switch to 2D, and click again. You can't select anything. This is because this call to Globe.pick is returning undefined.

(If this is a different issue, I can open a new ticket.)

[hpinkos]

Hey @thw0rted, that bug you're seeing is related to this issue:#2480
I've made a comment that you ran into this problem too

[thw0rted]

Thanks, @hpinkos ! I didn't see any workarounds mentioned on the other ticket -- do I just need to tell customers that WMS picking won't work in 2D for now?

[hpinkos]

Yeah, unfortunately I can't think of a good workaround. It's labeled high priority, but I'm not sure when we'll get a chance to look at it. If you'd like to take a stab at a solution, comment in that issue and someone from the team can give you some tips on where to get started.

[thw0rted]

Unfortunately the "hard math" bits are my biggest weakness -- I can usually track what everything is doing but once the vectors start normalizing I have to "step over" in the debugger :D

[OmarShehata]

Reported again here: https://groups.google.com/d/msg/cesium-dev/k1brfPffEec/GJUOPXywAAAJ

[vhive-jonathan-carse]

A very useful workaround for anyone getting here:

var viewer = new Cesium.Viewer("cesiumContainer");

var sseh = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);

sseh.setInputAction(function(event) {
  console.log('x', event.position);
  
  var cartesian = viewer.camera.pickEllipsoid(
    event.position,
    viewer.scene.globe.ellipsoid
  );
  
  //const pp = viewer.scene.pickPosition(event.position);
  
  if (cartesian) {
    const cart = Cesium.Cartographic.fromCartesian(cartesian);
    console.log(cart.longitude * (180 / Cesium.Math.PI));
    console.log(cart.latitude  * (180 / Cesium.Math.PI));
  }
}, Cesium.ScreenSpaceEventType.LEFT_DOWN);