  This paper is concerned with possibility of recovery of motion and structure
parameters from multiframes under perspective projection when only points on a
rigid body are traced. Free (unrestricted and uncontrolled) pattern of motion
between frames is assumed. The major question is how many points and/or how
many frames are necessary for the task. It has been shown in an earlier paper
{Klopotek:95b} that for orthogonal projection two frames are insufficient for
the task. The paper demonstrates that, under perspective projection, that total
uncertainty about relative position of focal point versus projection plane
makes the recovery of structure and motion from two frames impossible.
