POV-Ray : Newsgroups : povray.general : Feature request: speed of light Server Time
31 Jul 2024 02:26:15 EDT (-0400)
  Feature request: speed of light (Message 1 to 7 of 7)  
From: SharkD
Subject: Feature request: speed of light
Date: 28 Feb 2008 18:50:00
Message: <web.47c747c81018a7fdd57dbd0@news.povray.org>
I would like to request the addition of speed of the light rays. This would
allow one to explore things like doppler effects, as well as the difference
between the geometric versus apparent positions of the sun, moon and planets.


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From: Tim Cook
Subject: Re: Feature request: speed of light
Date: 28 Feb 2008 20:57:51
Message: <47c7669f@news.povray.org>
SharkD wrote:
> I would like to request the addition of speed of the light rays. This would
> allow one to explore things like doppler effects, as well as the difference
> between the geometric versus apparent positions of the sun, moon and planets.

You'd get interesting effects with long renders; light that had reached 
the camera plane on line 1 would be different from the light that 
reaches line 200, four hours later...

*snicker*

-- 
Tim Cook
http://empyrean.digitalartsuk.com

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From: John VanSickle
Subject: Re: Feature request: speed of light
Date: 28 Feb 2008 22:11:03
Message: <47c777c7$1@news.povray.org>
SharkD wrote:
> I would like to request the addition of speed of the light rays. This would
> allow one to explore things like doppler effects, as well as the difference
> between the geometric versus apparent positions of the sun, moon and planets.

Do the math, and someone will be happy to code it.

Regards,
John


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From: nemesis
Subject: Re: Feature request: speed of light
Date: 28 Feb 2008 23:30:01
Message: <web.47c789b87e6719d3d94a0a670@news.povray.org>
whew!  for a moment I thought it was about render speed...


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From: Warp
Subject: Re: Feature request: speed of light
Date: 29 Feb 2008 03:20:45
Message: <47c7c05d@news.povray.org>
SharkD <nomail@nomail> wrote:
> I would like to request the addition of speed of the light rays. This would
> allow one to explore things like doppler effects, as well as the difference
> between the geometric versus apparent positions of the sun, moon and planets.

  Would require using GR equations, which means curved rays. Not gonna
happen.

-- 
                                                          - Warp


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From: Gilles Tran
Subject: Re: Feature request: speed of light
Date: 29 Feb 2008 04:27:34
Message: <47c7d006$1@news.povray.org>

web.47c747c81018a7fdd57dbd0@news.povray.org...
>I would like to request the addition of speed of the light rays. This would
> allow one to explore things like doppler effects, as well as the 
> difference
> between the geometric versus apparent positions of the sun, moon and 
> planets.

I'm not sure if this is what you need, but there have been a few 
"relativistic" POV-Ray versions in the past :
http://physics.syr.edu/courses/PHY312.03Spring/mcdonald/phy312/index.html
http://www.fourmilab.ch/cship/cship.html
http://www.lehrer-online.de/povray-relativistisch.php

G.


-- 
*****************************
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- Graphic experiments
- POV-Ray, Cinema 4D and Poser computer images
- Posters


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From: David Buck
Subject: Re: Feature request: speed of light
Date: 29 Feb 2008 06:43:32
Message: <47c7efe4$1@news.povray.org>
SharkD wrote:
> I would like to request the addition of speed of the light rays. This would
> allow one to explore things like doppler effects, as well as the difference
> between the geometric versus apparent positions of the sun, moon and planets.
> 
> 

If you're going to worry about light speeds you also have to worry about 
astronomical distances.  POVRay doesn't work well with astronomical 
distances because of assumptions in the renderer that errors are within 
a certain fixed tolerance.

As well, if you're going to explore doppler effects, you need to change 
the RGB color model with a spectrum model which is more realistic.  A 
spectrum model contains a collection of brightnesses of many different 
wavelengths of light.  Objects would absorb some wavelengths and reflect 
others.  When you get the final wavelength value, you would convert the 
spectrum to RGB to render the pixel.

How do you red-shift an RGB color?  Red shifting a light spectrum is clear.

David Buck


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