POV-Ray : Newsgroups : povray.binaries.images : Clouds Server Time
13 Aug 2024 05:46:39 EDT (-0400)
  Clouds (Message 1 to 10 of 10)  
From: Andrew
Subject: Clouds
Date: 12 May 2003 21:26:57
Message: <3ec049e1@news.povray.org>
Yet another clouds picture.

I'm using a df3 with scattering and absorbing media against a Skylight
#include background.  I wrote a program to generate df3 files using
Perlin noise applied to a stack of ellipsoids.  It turned out quite
nice.


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Preview of image 'df3.jpg'
df3.jpg


 

From: Slime
Subject: Re: Clouds
Date: 13 May 2003 00:33:09
Message: <3ec07585@news.povray.org>
What was the render time?

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


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From: Marc Jacquier
Subject: Re: Clouds
Date: 13 May 2003 02:39:39
Message: <3ec0932b$1@news.povray.org>
Hi
df3 clouds are rendered rather fast.
If you want to experiment, have a look at Gilles Tran's MakeCloud new
macros.
http://www.oyonale.com/ressources/english/sources13.htm

They don't create df3 files the same way than Andrew's but the principles
are the same.

Marc


3ec07585@news.povray.org...
> What was the render time?
>
>  - Slime
> [ http://www.slimeland.com/ ]
>
>


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From: Andrew
Subject: Re: Clouds
Date: 13 May 2003 05:40:16
Message: <3ec0bd80@news.povray.org>
"Slime" <slm### [at] slimelandcom> wrote in message
news:3ec07585@news.povray.org...
> What was the render time?

As Marc Jacquier quite rightly says, they render fast.  This was chopped
out of a 1280x960 A0.3 render that took 45 minutes on my Athlon 2GHz.  I
used intervals 3 in the media and used interpolation on the df3.

I was inspired to do this by Gilles Tran's clouds macros, which showed
me how fast df3s render - I'd never experimented with media properly
before.  Right now I have to work on optimising my Perlin functions
(they would win prizes for inefficient coding right now) - then I might
give an animation a go.

Andrew


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From: Aaron Gillies
Subject: Re: Clouds
Date: 13 May 2003 08:08:54
Message: <3ec0e056$1@news.povray.org>
Very nice.  Realistic and fluffy.

Aaron


"Andrew" <ast### [at] hotmailcom> wrote in message
news:3ec049e1@news.povray.org...
> Yet another clouds picture.
>
> I'm using a df3 with scattering and absorbing media against a Skylight
> #include background.  I wrote a program to generate df3 files using
> Perlin noise applied to a stack of ellipsoids.  It turned out quite
> nice.
>
>
>


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From: Marc Jacquier
Subject: Re: Clouds
Date: 13 May 2003 15:15:25
Message: <3ec1444d$1@news.povray.org>

3ec0bd80@news.povray.org...
> "Slime" <slm### [at] slimelandcom> wrote in message
> news:3ec07585@news.povray.org...
> > What was the render time?
>
> I was inspired to do this by Gilles Tran's clouds macros, which showed
> me how fast df3s render - I'd never experimented with media properly
> before.
Nor did I :-/

> Right now I have to work on optimising my Perlin functions
> (they would win prizes for inefficient coding right now) - then I might
> give an animation a go.

I look forward :-)
>
Marc


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From: Andrew Coppin
Subject: Re: Clouds
Date: 13 May 2003 15:15:39
Message: <3ec1445b@news.povray.org>
Impressive...

Bet yet can't make big black storm clouds though ;-)

(They have a charicteristic "anvil" shape; it would be hard to get that out
of a random number generator...)

Andrew.

(This is where someone goes and proves me totally wrong ;-)


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From: Apache
Subject: Re: Clouds
Date: 13 May 2003 17:12:46
Message: <3ec15fce@news.povray.org>
> I look forward :-)
Because your eyes are at the front of your head  :-)


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From: Marc Jacquier
Subject: Re: Clouds
Date: 14 May 2003 02:18:29
Message: <3ec1dfb5@news.povray.org>
D'oh
I was wondering... :-)
Marc


3ec15fce@news.povray.org...
> > I look forward :-)
> Because your eyes are at the front of your head  :-)
>
>


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From: Early Ehlinger
Subject: Re: Clouds
Date: 15 May 2003 20:06:49
Message: <3ec42b99$1@news.povray.org>
"Andrew Coppin" <orp### [at] btinternetcom> wrote:
> (They have a charicteristic "anvil" shape; it would be hard to get that
out
> of a random number generator...)
>
> (This is where someone goes and proves me totally wrong ;-)

I won't prove it, but I'll offer a mechanism for somebody else to prove
it...

All you would need to do is this (pseudo-code, of course):

z = rand(minheight,maxheight)

min = min = hammer_min_width( z );
max = max = hammer_max_width( z );

x = rand(min,max)
y = rand(min,max)

Where:
  rand(min,max) returns a pseudorandom number between min and max
  hammer_min_width( z ) returns the minimum size of the cloud's cross
section at elevation z
  hammer_max_width( z ) returns the maximum size of the cloud's cross
section at elevation z

Granted, this would yield a group of objects that would have a square
sillhouette if viewed from above, but that could easily be solved by using a
slightly different equation for x & y, e.g., x = rand( min , max );  y^2 =
x^2 - 1;

--
-- Early Ehlinger CEO, ResPower Inc - Toll-Free : 866-737-7697
-- www.respower.com -- 500+ GHz Supercomputer Starting At USD$0.50/GHz*Hour


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