How about adding a 5th color channel: glow.
Every pixel that has a glow-value of 1 will glow with a pixel-radius
given in the global_settings.  0.5 will glow with half the intensity.

I hope you understand what I mean...?

ZK
http://www.povplace.be.tf
(You'll get an error-message if you follow that link.  Don't worry,
it's not important, it's just a JAVA-error...)

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In article <3916E1B5.DC497C5A@student.kuleuven.ac.be>, Zeger Knaepen 
<ZEG### [at] studentkuleuvenacbe> wrote:

> How about adding a 5th color channel: glow.
> Every pixel that has a glow-value of 1 will glow with a pixel-radius
> given in the global_settings.  0.5 will glow with half the intensity.

Umm, colors already have 5 channels(r, g, b, f, and t). And this sounds 
like something which will be taken care of by post_process filters...no 
need to modify something as basic as the color.

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

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In article <chrishuff_99-09163D.16555508052000@news.povray.org> , Chris Huff
<chr### [at] yahoocom>  wrote:

> And this sounds
> like something which will be taken care of by post_process filters...no
> need to modify something as basic as the color.

Hmm, and what about objects in a mirror?


       Thorsten

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In article <39173967$1@news.povray.org>, "Thorsten Froehlich" 
<tho### [at] trfde> wrote:

> Hmm, and what about objects in a mirror?

It depends on the filter...the most realistic way to do this seems to be 
to make a glow effect around extremely bright areas. This would work 
fine in a mirror. Otherwise, you should probably use emitting media, 
which also works in a mirror. If you use a per-object glow filter, 
reflections won't work, and neither will refracted portions.
How could this be done without a post_process filter, and without media? 
They seem to be the only solutions, and they work pretty well...maybe 
some more stuff from POV-AFX could be added, though.
Do you really think adding a "glow" component to colors is the best way 
to do it?

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

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The 6th color-element (glow) would have nothing to do with the actual
render-process.  The post-processor would use it to check if it should
add the glow or not.  I think this way is the most flexibel way to
implement the glowing.  Per-object glowing wouldn't be interesting, I
think.  Say I have a spaceship with windows.  The windows would be a
texture, but I would still want them to glow.  So for the lit windows
I would use something like: 
rgb 1 glow 1
This method gives no problem with mirrors, because the glow_amount (or
whatever you call it) is part of the color which get reflected.
Refraction wouldn't give a problem either.

ZK
http://www.povplace.be.tf

Chris Huff wrote:
> 
> In article <39173967$1@news.povray.org>, "Thorsten Froehlich"
> <tho### [at] trfde> wrote:
> 
> > Hmm, and what about objects in a mirror?
> 
> It depends on the filter...the most realistic way to do this seems to be
> to make a glow effect around extremely bright areas. This would work
> fine in a mirror. Otherwise, you should probably use emitting media,
> which also works in a mirror. If you use a per-object glow filter,
> reflections won't work, and neither will refracted portions.
> How could this be done without a post_process filter, and without media?
> They seem to be the only solutions, and they work pretty well...maybe
> some more stuff from POV-AFX could be added, though.
> Do you really think adding a "glow" component to colors is the best way
> to do it?
> 
> --
> Christopher James Huff - Personal e-mail: chr### [at] yahoocom
> TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
> Personal Web page: http://chrishuff.dhs.org/
> TAG Web page: http://tag.povray.org/

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In article <chrishuff_99-2DAF25.17571308052000@news.povray.org> , Chris Huff
<chr### [at] yahoocom>  wrote:

> Do you really think adding a "glow" component to colors is the best way
> to do it?

No, surely not.  Glow seems to be more of an additional kind of object (not
color) property to me.


      Thorsten

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Thorsten Froehlich <tho### [at] trfde> wrote...
> In article <chrishuff_99-2DAF25.17571308052000@news.povray.org> , Chris
Huff
> <chr### [at] yahoocom>  wrote:
>
> > Do you really think adding a "glow" component to colors is the best way
> > to do it?
>
> No, surely not.  Glow seems to be more of an additional kind of object
(not
> color) property to me.
>

However, the concept sounds very interesting to me.  Keeping this at 'glow'
seems a bit limiting, but if this were to be extended to contain some form
of general object information that would be used by the post-processing
filters, that might make it worthwhile.  Of course, adding a 6th component
to the color vector would cause a loss of performance (decreased speed and
increased memory usage).  Anyway, it is a creative idea that is at least
worth considering.

-Nathan

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I agree.

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In article <39180526$1@news.povray.org>, "Nathan Kopp" 
<Nat### [at] Koppcom> wrote:

> However, the concept sounds very interesting to me.  Keeping this at 
> 'glow' seems a bit limiting, but if this were to be extended to 
> contain some form of general object information that would be used by 
> the post-processing filters, that might make it worthwhile.  Of 
> course, adding a 6th component to the color vector would cause a loss 
> of performance (decreased speed and increased memory usage).  Anyway, 
> it is a creative idea that is at least worth considering.

I don't think it belongs in the color vector though. Of course, I don't 
think filter and transmit belong there either...I think they should be 
separate colors.
Maybe instead of adding things to the color vector, an "effect_map" 
object attribute would work...

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

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In article <39176851.C44A0F73@student.kuleuven.ac.be>, Zeger Knaepen 
<ZEG### [at] studentkuleuvenacbe> wrote:

> The 6th color-element (glow) would have nothing to do with the actual
> render-process.  The post-processor would use it to check if it should
> add the glow or not.  I think this way is the most flexibel way to
> implement the glowing.  Per-object glowing wouldn't be interesting, I
> think.  Say I have a spaceship with windows.  The windows would be a
> texture, but I would still want them to glow.

Then don't use per-object glowing, use brightness-threshold glowing. The 
windows are probably brighter than the surrounding hull, otherwise they 
wouldn't be glowing, so set the filter to make things at or above the 
"window brightness" glow.(I already have a sort-of-working version of 
this kind of effect, though it will be a while before I have anything 
useful.)

Or maybe additional information could be patterned and passed to the 
post_process stage with some kind of "effect_map". Certainly a better 
alternative than adding more stuff to color, where it doesn't really 
belong(for one thing, you could have a glow map independant of the 
pigment map).

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

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