Click and drag to rotate the camera.
	Control-click and drag to zoom in/out.
	UP Arrow: Move observer in the Z direction.
	DOWN Arrow: Move observer in the -Z direction.
	RIGHT Arrow: Move observer in the Y direction.
	LEFT Arrow: Move observer in the -Y direction.
	CONTROL + UP Arrow: Move observer in the X direction.
	CONTROL + DOWN Arrow: Move observer in the -X direction.
	I: Show/Hide instructions.