Greetings all,

Whenever I get the feeling that I'm getting to grips with 'media', it
damn well ANNOYS me again. Sorry about that, try to stay calm.
Okay, just two points really.

Firstly, in the POV docs it states that for the three media types,
only the red, green and blue values are used - transmit and filter are
ignored. Why is it then, that when using an unconstrained media ( as
atmosphere ), a specified 'background' color is only visible when rgb
0.3 is changed to rgbf 0.3, and then only when extinction is set at 0?

Secondly, I kind of got the impression from reading some of the recent
posts that the problem regarding media 'artefacts' ( especially as
seen in shadows ) is not a problem with media itself, but rather with
our inability to use it correctly. If this is the case, surely someone
must be able to explain how to use it. I'm tired of getting
beautifully smooth volumetric lighting UNTIL it encounters an object,
and then BRING ON THOSE ARTEFACTS. There doesn't seem to be anything I
can do about it.

Anyway...I'm still smiling nonetheless. 

Andy Cocker

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Alas, you see what I mean.
I know, I first used transmit and filter anyhow due to ignorance, I
didn't even there were color changes in the density_map until I saw it
happen.
Maybe your right (please be right!) about the lack of knowledge being
the reason.
But hey, you'd think by now I had tried all the extremes possible by
now. Can't do a linear test (float/vector transitions, evenly enough)
because of the time involved. Maybe someone will at least do that and
let the rest of us know the results. Maybe not....


Andrew Cocker wrote:
> 
> Greetings all,
> 
> Whenever I get the feeling that I'm getting to grips with 'media', it
> damn well ANNOYS me again. Sorry about that, try to stay calm.
> Okay, just two points really.
> 
> Firstly, in the POV docs it states that for the three media types,
> only the red, green and blue values are used - transmit and filter are
> ignored. Why is it then, that when using an unconstrained media ( as
> atmosphere ), a specified 'background' color is only visible when rgb
> 0.3 is changed to rgbf 0.3, and then only when extinction is set at 0?
> 
> Secondly, I kind of got the impression from reading some of the recent
> posts that the problem regarding media 'artefacts' ( especially as
> seen in shadows ) is not a problem with media itself, but rather with
> our inability to use it correctly. If this is the case, surely someone
> must be able to explain how to use it. I'm tired of getting
> beautifully smooth volumetric lighting UNTIL it encounters an object,
> and then BRING ON THOSE ARTEFACTS. There doesn't seem to be anything I
> can do about it.
> 
> Anyway...I'm still smiling nonetheless.
> 
> Andy Cocker

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/POVring.htm
=Bob

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Andrew Cocker <and### [at] acockerfreeservecouk> wrote:
: Secondly, I kind of got the impression from reading some of the recent
: posts that the problem regarding media 'artefacts' ( especially as
: seen in shadows ) is not a problem with media itself, but rather with
: our inability to use it correctly.

  Perhaps a more correct answer would be: The problem is not with media
itself, but with the sampling method used.
  Perhaps this will be fixed in the future?

-- 
main(i){char*_="BdsyFBThhHFBThhHFRz]NFTITQF|DJIFHQhhF";while(i=
*_++)for(;i>1;printf("%s",i-70?i&1?"[]":" ":(i=0,"\n")),i/=2);} /*- Warp. -*/

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