The camera represents our view in the 3D space; one way to explore and see more of the space is by moving the camera. The Camera class is defined as follows:
pi3d.Camera.Camera(at=(0, 0, 0), eye=(0, 0, -0.1),
lens=None, is_3d=True, scale=1.0)
The camera is defined by providing two locations, one to look at (usually the object we wish to see, defined by at) and another to look from (the object's position, defined by eye). Other features of the camera, such as its field of view (lens) and so on, can be adjusted or used with the default settings.
If we didn't define a camera in our display, a default one will be created that points at the origin (the center of the display, that is, 0,0,0), positioned slightly in front of it (0,0,-0.1 ...
