[Cin] Automatic keyframes of Camera and Projector

[Andrea paz]

Hi,
can anyone explain chapter 18, paragraph 18.4 of the manual-cv? I
refer to the automatic keyframes of camera and projector. I can't
understand the explanations and I can't even reproduce that behavior
in my tests. I don't see more than a box of cameras or projectors and
therefore I don't see even the motion paths that unite them.
Another question: what is the difference between the keyframe of the
camera and the keyframe of the projector?