POV-Ray : Newsgroups : povray.advanced-users : Difficult Light-Shadow Question... Server Time
29 Jul 2024 16:19:37 EDT (-0400)
  Difficult Light-Shadow Question... (Message 1 to 8 of 8)  
From: Tim Nikias
Subject: Difficult Light-Shadow Question...
Date: 4 Feb 2002 16:18:43
Message: <3C5EFA9F.82EAC54F@gmx.de>
Just me again!

So, I have following problem:
-50 discs
-using different, but algorithmically generated texture
-lit by one spotlight
-have to throw shadows onto themselves
-but should not throw shadows into the other scenery
-don't use lightgroups (they're buggy in the betas at the moment)

Any ideas?
To give you an idea what its about: I'm using textured discs as
slices through a cloud-scape. Thus, the slices have to throw
shadows onto themselves. But, when using the area-light
(only in this scene, in others, that'll probably be different),
they don't throw shadows on anything else, because the
shadows are blurred away.
Now, I could save tracing time (a lot!) if those shadows were
only calculated for the discs, not anything else.
But, as mentioned above, lightgroups are a little buggy and
difficult to implement into the existing scene.

Ideas, anyone?

--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html


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From: JRG
Subject: Re: Difficult Light-Shadow Question...
Date: 4 Feb 2002 18:02:14
Message: <3c5f12f6$1@news.povray.org>
Hmm not buggy lightgroups? Just use -ul and they should work as expected.

--
Jonathan.


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From: Tim Nikias
Subject: Re: Difficult Light-Shadow Question...
Date: 5 Feb 2002 16:58:59
Message: <3C605592.9400E6A3@gmx.de>
-UL doesn't work. Strange lighting:
Some objects aren't lit though in same lightgroup.
 Ah, well. Guess I'll take the longer rendering time and
the "more real" approach... ;-)


--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html


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From: Thorsten Froehlich
Subject: Re: Difficult Light-Shadow Question...
Date: 6 Feb 2002 05:10:51
Message: <3c61012b@news.povray.org>
In article <3C605592.9400E6A3@gmx.de> , Tim Nikias <tim### [at] gmxde>  wrote:

> -UL doesn't work. Strange lighting:
> Some objects aren't lit though in same lightgroup.
>  Ah, well. Guess I'll take the longer rendering time and
> the "more real" approach... ;-)

Or wait for beta 11 to test if the changes in there correct the problem.

    Thorsten

____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org


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From: Tim Nikias
Subject: Re: Difficult Light-Shadow Question...
Date: 6 Feb 2002 11:56:31
Message: <3C61602C.501319EE@gmx.de>
I actually noted that in my mind. I guess, that's what beta-testing is about:
-Find errors
-Verify them
-Make them known to the programmers
-check if fixes interfere with other options
-give standing ovations when everything is finished and the programmers
 did a magnificient job, and in the case of POV-Ray:

THEY DID IT AGAIN!

;-)

--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html


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From: Mike Williams
Subject: Re: Difficult Light-Shadow Question...
Date: 7 Feb 2002 13:03:23
Message: <L$FlQEA82kY8EwKO@econym.demon.co.uk>
Wasn't it Tim Nikias who wrote:
>Just me again!
>
>So, I have following problem:
>-50 discs
>-using different, but algorithmically generated texture
>-lit by one spotlight
>-have to throw shadows onto themselves
>-but should not throw shadows into the other scenery
>-don't use lightgroups (they're buggy in the betas at the moment)
>
>Any ideas?

Cheat: Render two separate images. One of the discs (with a transparent
background) and one of the other scenery, and combine the two with a
paint program. Or combine the two halves in POV by pulling in the disc
image as a no-shadow image-mapped plane over the other scenery.

-- 
Mike Williams
Gentleman of Leisure


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From: Grey Knight
Subject: Re: Difficult Light-Shadow Question...
Date: 7 Feb 2002 15:12:03
Message: <3C62DF8A.DC710AB4@namtar.qub.ac.uk>
Mike Williams wrote:
> 
> Cheat: Render two separate images. One of the discs (with a transparent
> background) and one of the other scenery, and combine the two with a
> paint program. Or combine the two halves in POV by pulling in the disc
> image as a no-shadow image-mapped plane over the other scenery.
> 
> --
> Mike Williams
> Gentleman of Leisure

If this is to do with Tim's IRTC entry (which I think it is...) then
cheating is definitely NAO! POV-Ray cheating might be permissible
though...

-- 
signature{
  "Grey Knight" contact{ email "gre### [at] yahoocom" }
  site_of_week{ url "http://digilander.iol.it/jrgpov" }
}


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From: Tim Nikias
Subject: Re: Difficult Light-Shadow Question...
Date: 7 Feb 2002 15:57:43
Message: <3C62EA34.F38E1B20@gmx.de>
Right. Cheating is NAO, and I actually try to
stick to the real result of an image.

IRTC is about not-cheated, but well-designed /-scripted,
/-modelled or /-"whatever useful" images, so thats what
I wanted to produce.


--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html


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