Allow viewport/matrix override

[unknownbrackets]

Allow some way to, essentially, expand the viewport or change the perspective and inspect the scene. Or even lock the current viewport, ignoring changes to it.

Would be nice to associate this with arrow keys or even analog control movement while in override mode.

This might allow you to see objects outside the scene to understand a rendering problem better.

Someone mentioned Dolphin has a "free camera" feature that sounds similar.