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26 Nov 2024 07:48:07 EST (-0500)
  Floating point accuracy (Message 1 to 6 of 6)  
From: Anthony D  Baye
Subject: Floating point accuracy
Date: 8 Feb 2011 14:35:00
Message: <web.4d519a04579fd3e9d7f39bd00@news.povray.org>
One of my works in progress is an orbital view of a planet with a satellite at
relatively close range.  The problem is that I need a fairly fine detail on the
satellite, so I've modeled it at 1 unit = 1 inch, but a planet of the same scale
doesn't render properly.

So I'm fishing for suggestions.

Regards,
A.D.B.


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From: clipka
Subject: Re: Floating point accuracy
Date: 8 Feb 2011 14:43:15
Message: <4d519cd3$1@news.povray.org>
Am 08.02.2011 20:31, schrieb Anthony D. Baye:
> One of my works in progress is an orbital view of a planet with a satellite at
> relatively close range.  The problem is that I need a fairly fine detail on the
> satellite, so I've modeled it at 1 unit = 1 inch, but a planet of the same scale
> doesn't render properly.
>
> So I'm fishing for suggestions.
>
> Regards,
> A.D.B.

Scale the whole scene down? Just because you've modelled a satellite at 
1 unit = 1 inch doesn't mean you can't just "scale 0.01" it ;-)

Fake it, scaling down the planet and moving it closer to compensate?

Render the planet separately using a spherical camera, and then using 
that as a sky sphere?


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From: stbenge
Subject: Re: Floating point accuracy
Date: 8 Feb 2011 15:29:05
Message: <4d51a791@news.povray.org>
On 2/8/2011 11:31 AM, Anthony D. Baye wrote:
> One of my works in progress is an orbital view of a planet with a satellite at
> relatively close range.  The problem is that I need a fairly fine detail on the
> satellite, so I've modeled it at 1 unit = 1 inch, but a planet of the same scale
> doesn't render properly.
>
> So I'm fishing for suggestions.

One thing that works for me is to create two scenes. In one scene, 
render the planet very small, with a correspondingly small camera angle. 
Copy the camera settings into another scene file, but with a new, 
desired camera angle. Map the image of the planet onto a box using 
Rune's illusion.inc.

Sam


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From: Stephen
Subject: Re: Floating point accuracy
Date: 8 Feb 2011 15:36:52
Message: <4d51a964$1@news.povray.org>
On 08/02/2011 7:43 PM, clipka wrote:
> Fake it, scaling down the planet and moving it closer to compensate?

That's what I'd do. :-D

-- 
Regards
     Stephen


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From: Thomas de Groot
Subject: Re: Floating point accuracy
Date: 9 Feb 2011 03:28:28
Message: <4d52502c@news.povray.org>
"Stephen" <mcavoys_at@aoldotcom> schreef in bericht 
news:4d51a964$1@news.povray.org...
> On 08/02/2011 7:43 PM, clipka wrote:
>> Fake it, scaling down the planet and moving it closer to compensate?
>
> That's what I'd do. :-D

Me too, and you only have to determine the apparent size of the planet. You 
probably can calculate it, but I did it once in Moray just by moving spheres 
around :-)

Thomas


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From: Warp
Subject: Re: Floating point accuracy
Date: 10 Feb 2011 11:55:12
Message: <4d541870@news.povray.org>
Anthony D. Baye <Sha### [at] spamnomorehotmailcom> wrote:
> One of my works in progress is an orbital view of a planet with a satellite at
> relatively close range.  The problem is that I need a fairly fine detail on the
> satellite, so I've modeled it at 1 unit = 1 inch, but a planet of the same scale
> doesn't render properly.

  If you scale the planet down several orders of magnitude and move it
closer, it will look identical.

-- 
                                                          - Warp


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