P3D Re: Mask illusions

[Ronald Beck <ronald-beck@xxxxxxxxxxxx>]

> > >Viewed at a distance the depth appears reversed, i.e., instead of the
> > >hollow (back) end, one normally sees the front of the mask, a face, looking
> > >at them.  The illusion is so strong that most people have to come very
> > >close or even touch the mask to get back the correct hollow image.
> 
> This is the same illusion used by Disney Imagineers in the Haunted House
> in Disney World in Florida. There is a section where your car is pulled
> past a series of marble looking busts of men's heads. These faces appear
> to be 3D, and rotate to follow YOU as you go by. Of course, they
> couldn't all be following just you if the next guy thinks they are
> following him, or the next gal her... A clever use of the effect! I look
> forward to seeing it again in two weeks... =)
> 

We were stopped in front of these faces for about 15 minutes the last
time I rode this ride and I continuously stared at these trying to
figure out just how it worked.  I was under the impression that the
marble looking busts were simply featurless heads (with protruding nose)
that had the face projected on.  I know that the face was projected
because the picture of the bust I took had a smooth front.  I could not
tell though whether these were convex or concave.  I was tempted to get
out and make a close visual inspection (we were in there that long!) but
my boys were 3 and 1 and would not have liked dad leaving the car.

Regards,
Ron