POV-Ray : Newsgroups : povray.general : Re: fading media Server Time
6 Nov 2024 16:31:18 EST (-0500)
  Re: fading media (Message 1 to 1 of 1)  
From: Christopher James Huff
Subject: Re: fading media
Date: 4 Aug 2002 22:50:42
Message: <chrishuff-B319FA.21413904082002@netplex.aussie.org>
In article <3d4d9316@news.povray.org>,
 "Johan Feyaerts" <joh### [at] no_spamskynetbe> wrote:

> I've been doing some trials with media in an attempt to model some neon
> lights. Is there a way to make the media fade out in the outer cylinder so
> that the boundary of the shining light is less sharp? I'd like to make the
> light more intense closer to the bulb and less intense far away from the
> bulb. Any suggestions?

If you are going to ask a question, you are more likely to get an answer 
in one of the discussion groups, like povray.general or 
povray.advanced-users. This group was the right place for the scene 
file, the wrong one for the image and question. The best way would be to 
post your message in a discussion group and the image in 
povray.binaries.images. Followups to this message are set to 
povray.general.

About your question: you could make a custom density pattern using a 
function, you would need to know a bit of mathematics though and it 
would get more difficult for more complex light shapes. One possibility 
is to create several versions of the object with increasing radius and 
combine these in a function pattern using the inside() function. This 
would be easier if the object was created with a macro, so you didn't 
have to duplicate it by hand for each new radius.
What you seem to be trying to simulate here is atmospheric scattering of 
the light coming from the neon tube...you could place a lot of light 
sources inside the tube and use scattering media, but it would probably 
be too slow to be practical.
If you are willing to give up the refinements of POV 3.5, you could use 
MegaPOV for its "glow" feature, which would be fast rendering at least.

-- 
Christopher James Huff <chr### [at] maccom>
POV-Ray TAG e-mail: chr### [at] tagpovrayorg
TAG web site: http://tag.povray.org/


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