And you don't create a direct copy of your main scene. You add different geometry to the minimap scene, to account for the fact that the view is smaller. Sure, you need some means of tying the minimap geometry and the main view geometry together, but that should be trivial if designed right.
Thanks. I want to solve this problem by automatically create a readable by some calculation or specific shader. Is this valuable? I mean is it valuable or worth to find a solution to automatically create a minimap that meets our needs and reduce the work to create a second scene?