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18 Nov 2024 03:17:41 EST (-0500)
  large sphere odd behaviour (Message 1 to 3 of 3)  
From: Rohan Bernett
Subject: large sphere odd behaviour
Date: 21 Oct 2002 00:30:03
Message: <web.3db382278c796a70d02c7b870@news.povray.org>
I tried making a really huge sphere for some stars out in space, and if the
radius was too large, it would dissappear past a certain point. Anyone know
why?

Rohan _e_ii


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From: hughes, b 
Subject: Re: large sphere odd behaviour
Date: 21 Oct 2002 00:45:38
Message: <3db38672$1@news.povray.org>
"Rohan Bernett" <rox### [at] yahoocom> wrote in message
news:web.3db382278c796a70d02c7b870@news.povray.org...
> I tried making a really huge sphere for some stars out in space, and if
the
> radius was too large, it would dissappear past a certain point. Anyone
know
> why?

POV-Ray isn't limitless, basically, is why. I don't know the exact reasons
but there's a value in the program code called Epsilon which numerical
values are based around in some way.

So, there are limits found when using either very small or very large
numbers for the objects. The sky_sphere is designed to be infinite, so
that's the alternative. Aside from keeping to within reasonable scales if
using object primitives anyway.


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From: Slime
Subject: Re: large sphere odd behaviour
Date: 21 Oct 2002 00:55:39
Message: <3db388cb$1@news.povray.org>
> I tried making a really huge sphere for some stars out in space, and if
the
> radius was too large, it would dissappear past a certain point. Anyone
know
> why?

Anything above 1*10^10 disappears. If it didn't work that way, there would
be floating point errors.

Try using a sky_sphere, or, if you're making a planet or something, decrease
the distance while simultaneously decreasing the radius by the same factor.

 - Slime
[ http://www.slimeland.com/ ]


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