Below is the famouse flying field in Australia where SITL flies there by default. As we can see the map is displayed in 3D, and from multiple views. A camera is attached to drone and can be controlled via buttons. Another camera is following the drone.
The above map uses flat landscape, i.e. the map is created on a 2D Plan, but the environement is a 3D environment.
The below image shows one step forward, it creates 3D mesh of the map and adjust drone absolute altitude accordingly based on drone home location.
This project is in its very early stage, it is free and open-source and can be accessed here. I hope people start to use and contribute to it.