How do I project shadows in Arcgis Runtime for Java

I'm using the Esri Arcgis Runtime for Java. I'm creating "waypoints" in 3d space and it's hard to judge their distance from the ground. Adding a shadow would be useful. I've set the time to January noon, but no shadow is shown. The lines and points are Graphic Symbols, not necessarily 3D objects.

How do I cast shadows?

sceneView.setSunLighting(LightingMode.LIGHT_AND_SHADOWS);
sceneView.setAmbientLightColor(0xFFFFFFFF);
Calendar c = Calendar.getInstance();
c.setTime(new GregorianCalendar(2020, Calendar.JANUARY, 6, 12,0).getTime());
sceneView.setSunTime(c);