Snapshot as a 3D scene

[benbovy]

From Luca's feedback:

For the wow effect, I realized that not having a 3d perspective was maybe missing for some folks. The version last year was a much higher resolution and it was a winner when people could pick the view angle.

Technically, showing a 3D scene that is updating in real-time is a bit too heavy to produce smooth results. That said, we could easily add a button to take a snapshot of the topography and render it in another 3D widget (displayed next to the real-time simulation visualization) with, e.g., ipygany or pyvista.