CameraFollow

This is a thing I mocked up from a tutorial on how to make a minimap. 

Notes on use:
new camera, set view over the main camera at height appropriate for bird's eye minimap, depth equal to the main camera, no extra layers visible, adjust Normalized View Port Rect to mess around with minimap.

For optimisation copy terrain in the hierarchy and cut the base map distance, drop all the other details, and raise pixel error. Uncheck minimap camera from the main terrain, and uncheck everything else from the minimap camera. Important since otherwise the minimap will take just as many resources as the normal camera and have the entire thing drawing way more than it needs to.