I use camera.flyTo(), and then tilt the camera, the view goes underground. (even in the sandcastle Camera example, I met the same problem)
If I don’t use flyTo(), (e.g., zoom in manually or use setView), I never go underground.
This may be a bug. And I wonder how to fix it.
My Cesium is 1.36. The figure below is the camera underground with 3d-tiles model.
Any help appreciated.