"Kenneth" <kdw### [at] gmailcom> wrote:
>
> As wonderful as the code is, it's not set up FOR animation (and probably
> wasn't designed for that anyway, as the code *relies* on the camera position
> being well-defined.) That is, a FREELY-moving camera introduces distortion
> into the applied image--not really parallax distortion but something else.
> There's no easy/quick solution in the parameter settings...

Well, I'm happy to admit that I was completely wrong about this (and my
apologies to Rune!) His code works as-is and wonderfully for animation, even
with a wildly-moving camera. The overlaid image and the objects continue to
match up--and with no *unexpected* distortion. The camera's location, look_at,
and even sky (for rotating the camera) all work with absolutely no problem...and
those changing variables don't even need to be plugged into his code! (That is,
once everything is initially set up at the camera's 'sweet spot' as illustrated
in my image post.) The final 'quasi-3D' result is really nice. I'm rather amazed
that a single image_map can do this.

I even *tried* to make things screw up; but Rune's code handled those attempts
with grace and aplomb. ;-)

When doing my initial tests of his code, I used a simple grid image, overlaid
onto some random shapes. In moving the camera, the visual result looked odd
(except at the 'sweet spot'), since the 'combined image overlay' no longer
looked square but trapezoidal; and I just *assumed* that by moving the camera I
had introduced some 'bad' distortion. But when I re-made the objects
accurately--and aligned them to the image--it turned out that what I was seeing
was in fact correct behavior.

Yes, the image_map *can* look somewhat distorted, when the camera moves way 'out
of bounds'. But that's no fault of Rune's code; it's a natural consequence of
the image_map's pixels having to 'stretch' to cover any perspective-receding
geometry in the scene, if the camera tries to look straight-on at those object
planes. (Yet the image is still nicely glued to the object.) So the usefulness
of the technique in animation requires a somewhat limited camera movement--but
not so limited as I originally thought, which is a really nice discovery. It can
all be judged by eye.

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