POV-Ray : Newsgroups : povray.general : Media randomness Server Time
12 Aug 2024 11:24:14 EDT (-0400)
  Media randomness (Message 1 to 3 of 3)  
From: Ole Laursen
Subject: Media randomness
Date: 28 Feb 1999 16:11:28
Message: <36d9b100.0@news.povray.org>
Hi!

How do I make 2 medias with the same settings for color_map, emission and
turbulence etc. look different as if they had used a different seed value
for their randomness?

I'm making some cloud-looking medias with the spherical pattern function,
and I need to get two clouds that look similar, to some extent (they
shouldn't be totally the same).

Thanks in advance (I hope I didn't asked for something that is in a FAQ
somewhere :-)!

Ole Laursen - Aalborg, Denmark - ole### [at] hardworkingdk
When do you want to crash today? (note: new address!)


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From: Ken
Subject: Re: Media randomness
Date: 28 Feb 1999 16:16:50
Message: <36D9B1AA.E13A079C@pacbell.net>
Ole Laursen wrote:
> 
> Hi!
> 
> How do I make 2 medias with the same settings for color_map, emission and
> turbulence etc. look different as if they had used a different seed value
> for their randomness?
> 
> I'm making some cloud-looking medias with the spherical pattern function,
> and I need to get two clouds that look similar, to some extent (they
> shouldn't be totally the same).
> 
> Thanks in advance (I hope I didn't asked for something that is in a FAQ
> somewhere :-)!
> 
> Ole Laursen - Aalborg, Denmark - ole### [at] hardworkingdk
> When do you want to crash today? (note: new address!)

  Try using rand() with the turbulence to vary shape.

-- 
Ken Tyler

mailto://tylereng@pacbell.net


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From: Nathan Kopp
Subject: Re: Media randomness
Date: 28 Feb 1999 16:30:32
Message: <36D9B57A.92A38604@Kopp.com>
Ken's suggestion is good.  Another option is to use warps.  Instead of
adding regular turbulence, translate the media, and a turbulence warp,
then translate the media back to its original position.

i.e.
  media {
    // media options & density stuff here
    translate 10*x
    warp { turbulence 1 }
    translate -10*x
  }

Turbulence is based on the DNoise fractal noise function (which is the
similar to what bozo uses), therefore, the turbulence at one spot in space
is different from the turbulence at another spot in space.

-Nathan


Ole Laursen wrote:
> 
> Hi!
> 
> How do I make 2 medias with the same settings for color_map, emission and
> turbulence etc. look different as if they had used a different seed value
> for their randomness?
> 
> I'm making some cloud-looking medias with the spherical pattern function,
> and I need to get two clouds that look similar, to some extent (they
> shouldn't be totally the same).
> 
> Thanks in advance (I hope I didn't asked for something that is in a FAQ
> somewhere :-)!
> 
> Ole Laursen - Aalborg, Denmark - ole### [at] hardworkingdk
> When do you want to crash today? (note: new address!)


Post a reply to this message

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