I was working on a text example with show and ran into several annoyances related to cameras. I figured I'd list these, along with existing related issues, and then do a proper camera/controller refactoring soon.

• When providing a camera to Display, it should use not update the view, because I already carefully set the initial view.
• The zoom for an OrbitController on a OrthographicCamera is broken, it should set the bounds when Controller.zoom_changes_distance is set.
• Make PanzoomController work with a perspective camera.
• Use @property's.
• Ability to scale camera-axii individually #388. A start was made in #356, but it seems a bit stuck on some of the above issues.
• Make sure that the docs are complete #113
• Update projection matrix in camera.show_object #231
• Controller does not request draw on load_state #300 (but also allow user to determine when to draw)
• Automatically update the camera (but also allow users to determine when it happens).

Also a proposal: a controller is in most cases already directly associated with a specific camera because of add_default_event_handlers. My proposal is to make the wrapping explicit, and drop the need to call update_camera on each draw. I think this will simplify both internal and user code. Needs some though on the edge cases for controlling multiple camera's, but we'll figure that out.

Most work was done in #457. Here are the leftovers:

• Trackball controller.
• Fly controller.
• Smooth camera movement #365
• Make key-mouse-bindings configurable.
• Better default bindings? (e.g. panning is not consistent).