🚀 go-pugleaf

toddl@county.lmt.mn.org (Todd Lehman) writes:

>Has anyone else observed this ghosting effect?  Does anyone know what is
>the cause?  I believe it to be an optical illusion, since the ghosting is
>not there when your eyes remain fixed.  It's the same kind of effect you

Yes, I have seen this effect.  What happens, is your eyes try to follow
the object at a smooth velocity,and the object looks like it is jumping
back and forth by delta/2.

In the following sequence of frames, the 'O' represents the point your
eye is following:

+---+
|O  |
+---+
+---+
|  O|
+---+
    +---+
    |O  |
    +---+
    +---+
    |  O|
    +---+


So as your viewpoint moves right at 2 chars per frame, it looks like the
object is first centered on char to the right, then one char to the
left, one to the right, and so on.

For some reason, it does not seem as apparent with 3d scenes; perhaps
because there is less purely-linear motion.

Better frame rates are still usefull with 3d, though.  12.5fps looks
_much_ smoother than 8.33.  Six fps is still enough for a convincing
sense of motion, so it's more a cosmetic detail.

Christopher Jam                       c64 forever!!!!!