Set up multiple export "cameras"

Allow us to set up multiple export cameras so that exports can be done from points of our choosing, rather than just the center of the map.

For example, from a map with three rooms, if I choose, I might want to set up a camera centered above each room, generating three exports from those three different "cameras".

This would allow us to decide where to center the 3D perspective exports for the area of our choice. With the option to do this from multiple cameras, you wouldn't have to split up large maps to avoid the strange projection in the far corners.