I should also mention my image is quite unrealistic, because the size of 
that planet would suggest we're much closer to it than a moon should be 
(unless it's a very low-density planet). It should be further away (or 
smaller, all things are relative), and then I would have to zoom the camera 
in more if I wanted it this large in frame, which would give the flattening 
effect (though it would also flatten the foreground). I wanted to get the 
appearance of a deliberately exagerated classic sci-fi illustration.

-- 
Tek
http://evilsuperbrain.com

"Tek" <tek### [at] evilsuperbraincom> wrote in message 
news:4bdead14@news.povray.org...
> "Kenneth" <kdw### [at] earthlinknet> wrote in message 
> news:web.4bde94823d08c812ae92d9930@news.povray.org...
>>
>> (I'm curious about the gas-giant planet's appearance; really HUGE objects 
>> that
>> are far off in the distance show a sort of visual 'compression'. There's 
>> really
>> nothing that we see on earth that would be similar, of course, so it's 
>> hard to
>> visualize. But the 'effect' would, I think, be the same as if you 
>> squashed-down
>> your textured planet in z. (Squashing it in-line with the camera.) OR, 
>> placed it
>> WAY off into space while increasing its size accordingly. The only 
>> similar
>> example I can think of is the planet Saturn, when it's viewed NOT edge-on
>> through a telescope. It's an experiment I've been meaning to try in 
>> POV-Ray, but
>> haven't gotten around to.)
>
> The only squashing effect I'm aware of is when viewing through a 
> telescope, which is the same flattening effect you get with a zoom lens, 
> this image has a non-zoomed field of view so you wouldn't see squashing.
>
> The squashing is because the more you zoom in, the narrower your field of 
> view, the closer to parallel the edges of your view become, so the less 
> perspective you have in the image. With a wide field of view objects 
> further away get a lot more perspective, so get smaller quicker, a zoomed 
> lens keeps things much more similar sizes.
>
> The planet in my image is placed by positioning it relative to the camera, 
> then moving it away and scaling it up as you suggest (in fact the camera 
> is at <0,0,0> so I just scale the planet). However this does not alter the 
> appearance of the planet, any ray traced toward it will still hit the same 
> part, and it won't appear any more flattened (because it is physically 
> bigger by the same amount that it's been pushed away).
>
> You know, it's probably easier to just show you. Here's a simple scene, 
> the second image shows the same scene viewed from 5x further away, with a 
> camera zoomed in appropriately.
>
> -- 
> Tek
> http://evilsuperbrain.com
>
>
>

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