POV-Ray : Newsgroups : povray.newusers : Why does this look totally different today than it did in 1997? Server Time
28 Nov 2024 08:38:17 EST (-0500)
  Why does this look totally different today than it did in 1997? (Message 1 to 5 of 5)  
From: John M  Dlugosz
Subject: Why does this look totally different today than it did in 1997?
Date: 10 Mar 2001 22:08:03
Message: <3aaaec13@news.povray.org>
The picture seen at http://green.dlugosz.com/files/lamp1.3.jpg is a
re-render of http://www.dlugosz.com/Artwork/POV/lamp1.JPG which was made in
1997.  Someone else here helped me with a first cut of turning the halo into
a media, but

1) with MegaPOV, the floor looks different.  It looks fine if I turn off
"version unofficial", so what difference is making T_Stone9 come out wrong?

2) the brightness of the glass is different.  Same look with "unofficial"
turned on or off.  (walls are exactly the same, so it's not gamma
adjustment)

3) there is a bright stripe on the floor where there was a dark stripe
(shadow) before.  What??

Source file at http://green.dlugosz.com/files/lamp1.3.pov

Thanks,
--John


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From: Bob H 
Subject: Re: Why does this look totally different today than it did in 1997?
Date: 10 Mar 2001 22:33:13
Message: <3aaaf1f9@news.povray.org>
It's the caustics in the glass texture.  Don't know why it would have been
dark in regular POV though.  I thought it could only be the transmit of
either the media container of the glass texture but the glass is filtered
instead.  And I changed the media container to rgbf and it made no
difference.  So, it is the caustics 1 making the bright shadow.  Probably
the fact that the stone texture is layered and that has changed to have
transmitted pigments instead of filtered ones.  That meaning the underlying
layers show through much more unchanged.  At least this is what I remember.

Bob H.

"John M. Dlugosz" <joh### [at] dlugoszcom> wrote in message
news:3aaaec13@news.povray.org...
> The picture seen at http://green.dlugosz.com/files/lamp1.3.jpg is a
> re-render of http://www.dlugosz.com/Artwork/POV/lamp1.JPG
>
> 1) with MegaPOV, the floor looks different.  It looks fine if I turn off
> "version unofficial", so what difference is making T_Stone9 come out
wrong?
>
> 2) the brightness of the glass is different.  Same look with "unofficial"
> turned on or off.  (walls are exactly the same, so it's not gamma
> adjustment)
>
> 3) there is a bright stripe on the floor where there was a dark stripe
> (shadow) before.  What??
>
> Source file at http://green.dlugosz.com/files/lamp1.3.pov


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From: Rick [Kitty5]
Subject: Re: Why does this look totally different today than it did in 1997?
Date: 11 Mar 2001 08:22:01
Message: <3aab7bf9@news.povray.org>
i wouldn't worry, looks better......


--
Rick

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From: John M  Dlugosz
Subject: Re: Why does this look totally different today than it did in 1997?
Date: 11 Mar 2001 14:33:44
Message: <3aabd318$1@news.povray.org>
> Probably
> the fact that the stone texture is layered and that has changed to have
> transmitted pigments instead of filtered ones.  That meaning the
underlying
> layers show through much more unchanged.  At least this is what I
remember.

Ah yes, I remember something about that, too.  I also thought it had been
fixed, or had the #version in each inc file to make it automatic.

BTW, I rendered it with official POV and found the same results re glass and
shadows.

> It's the caustics in the glass texture.  Don't know why it would have been
> dark in regular POV though.  I thought it could only be the transmit of
> either the media container of the glass texture but the glass is filtered
> instead.  And I changed the media container to rgbf and it made no
> difference.  So, it is the caustics 1 making the bright shadow.

Yes, commenting out "caustics" makes the picture look like it did before, re
the lightness of the glass and its shadow.  I suppose that in the older
version of POV that was in use in 1997, this did not work, or has been
changed.

(later)

Moving the "caustics" line from the texture to an "interior" block in the
object, as the warning suggests, also makes the problem go away!  So this
seems to be a bug in the backward-compatibility feature.  Is someone keeping
a list?

--John


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From: John M  Dlugosz
Subject: Re: Why does this look totally different today than it did in 1997?
Date: 11 Mar 2001 16:50:01
Message: <3aabf309$1@news.povray.org>
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"John M. Dlugosz" <joh### [at] dlugoszcom> wrote in message
news:3aabd318$1@news.povray.org...
> > Probably
> > the fact that the stone texture is layered and that has changed
> > to have transmitted pigments instead of filtered ones.  That
> > meaning the
> underlying
> > layers show through much more unchanged.  At least this is what I
> remember.
>
> Ah yes, I remember something about that, too.  I also thought it
> had been fixed, or had the #version in each inc file to make it
> automatic.
>

The work-around, other than changing rgbf to rgbt in the inc files,
is to put #version around the texture usage.  This fixed it for 0.6A,
but NOT for 0.7.  See my note in povray.unofficial.patches.

- --John

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