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30 Jul 2024 16:13:35 EDT (-0400)
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From: Thomas de Groot
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 18 Nov 2011 07:20:54
Message: <4ec64da6$1@news.povray.org>


> Meanwhile, before I even tried this, I tried to modularize my scene
> script (which started to become difficult to handle, at 1,800 lines of
> code) by placing the radiosity, pigment, finish and texture definition
> in separate files - and instantly messed up the code completely!

Building a scene from modules is a good way to go instead. It is 
something I often do myself. Learning from past errors: I always start 
from a copy of the original scene :-) I know perfectly well what you are 
going through.
However, you can best leave the radiosity statement in the main scene 
file along with all general things like the light, the sky, etc, and 
include the texture definitions from an external file.

> I obviously am too stupid to learn anything from any mistake...

Don't hate yourself. Shit happens, like they say...

>
> I'm about to catch the next time machine to some Nazi death camp and get
> myself gassed... I HATE MYSELF FOR BEING SO DYSFUNCTIONAL!!!
>
> Or is there anyone among you who would like to kill me? I'm totally fed
> up with myself!!!

Before you go, or before the next hitman makes an appointment with you, 
just take a beer and consider life without POV-Ray ;-)

>
> UARGH!!!!

Now, that should have relieved you! Yell again!

Thomas


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From: Cousin Ricky
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 18 Nov 2011 13:30:01
Message: <web.4ec6a36c4ccf544d85de7b680@news.povray.org>
=?ISO-8859-1?Q?J=F6rg_=27Yadgar=27_Bleimann?= <yaz### [at] gmxde> wrote:

> I obviously am too stupid to learn anything from any mistake...

I don't believe you.

Look back at your personal Web site.  You confess to having lots of setbacks and
mistakes over the years trying to model Afghanistan.  And you learned.

You can do it again.  Just give it more time and effort.

> I'm about to catch the next time machine to some Nazi death camp and get
> myself gassed... I HATE MYSELF FOR BEING SO DYSFUNCTIONAL!!!

I hope you're just kidding.  If not, then please see a doctor.

> Or is there anyone among you who would like to kill me? I'm totally fed
> up with myself!!!

If we kill you, then you'll *never* learn about radiosity.  Plus, we'll lose a
fellow POV-Ray user.

This too, shall pass.

Sleep on it.


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From: Robert McGregor
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 18 Nov 2011 18:30:01
Message: <web.4ec6ea0b4ccf544d94d713cc0@news.povray.org>
=?ISO-8859-1?Q?J=F6rg_=27Yadgar=27_Bleimann?= <yaz### [at] gmxde> wrote:
> However, one problem remains: increasing gray_threshold doesn't
> help this time, the shadows remain bluish! Where do I find a 3.7 manual
> to look it up (no, I don't have the Windows version)?

Shadows actually /are/ bluish on a sunny day with clear blue sky, and your sky
is very blue; I think the radiosity is taking that into account, just as in the
real world.

Try changing your sky color to red and see if you get red shadows...

Cheers,
Rob
-------------------------------------------------
www.McGregorFineArt.com


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From: Jörg 'Yadgar' Bleimann
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 19 Nov 2011 16:24:17
Message: <4ec81e81$1@news.povray.org>
Hi(gh)!

Am 18.11.2011 19:26, schrieb Cousin Ricky:

> I don't believe you.
>
> Look back at your personal Web site.  You confess to having lots of setbacks and
> mistakes over the years trying to model Afghanistan.  And you learned.

But my learning curve is very, very flat... when I compare myself to 
those whizkids who know PoV-Ray barely for a year and come up with 
sophisticated scenes, then I really would like to kill not myself (I'm 
even too phlegmatic for suicide!), but to delete all PoV-Ray 
applications and project data and from now on content myself with 
watching TV and drinking cheap canned beer like all the other underclass 
losers do...

> You can do it again.  Just give it more time and effort.

And that's the problem... I'm not used to giving effort (in any fields 
of life) anymore, effort just HURTS! And when I try and try and try and 
even the 22nd attempt is the same failure as the first, then I wonder 


> I hope you're just kidding.  If not, then please see a doctor.

Fortunately, there are no time machines... and as I mentioned, I'm even 
too dysfunctional to kill myself! If I tried, I probably would totally 
blow the job and instead of simply ceasing to exist (or, the Christian 
version, ending up in Satan's eternal Auschwitz, as I'm no born-again 
turbo-evangelical), I would find myself as a coma patient for years and 
years in some intensive neurology ward...

> This too, shall pass.
>
> Sleep on it.

Not even this works after gallons of strong "programmer's coffee"...

See you in Khyberspace!

Yadgar


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From: Jörg 'Yadgar' Bleimann
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 19 Nov 2011 16:28:22
Message: <4ec81f76@news.povray.org>
Hi(gh)!

Am 19.11.2011 00:28, schrieb Robert McGregor:

> Shadows actually /are/ bluish on a sunny day with clear blue sky, and your sky
> is very blue; I think the radiosity is taking that into account, just as in the
> real world.
>
> Try changing your sky color to red and see if you get red shadows...

Of course I know of this... but I would like to create a scene matching 
my *subjective* recalls of bright summer days - even in the 
Mediterranean, I can't remember shadows being THAT blue!

But meanwhile I found out that it's simply because of the missing 
#version 3.7 - after I added this at the beginning of my code, the 
gray_threshold value was taken into account once more!

See you in Khyberspace!

Yadgar


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From: clipka
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 19 Nov 2011 20:28:57
Message: <4ec857d9@news.povray.org>

>
> But my learning curve is very, very flat... when I compare myself to
> those whizkids who know PoV-Ray barely for a year and come up with
> sophisticated scenes, then I really would like to kill not myself (I'm
> even too phlegmatic for suicide!), but to delete all PoV-Ray
> applications and project data and from now on content myself with
> watching TV and drinking cheap canned beer like all the other underclass
> losers do...

Oh, come on - I know we're heading towards winter time, and people all 
over the northern hemisphere are going into hibernation mode (aka 
depression), but please... we just managed to convince Orchid aka 
Invisible that /he/'s not "completely dysfunctional", so don't /you/ 
start now... >_<

Just look at me, for instance. I guess you'd file me under "whizkid", 
with all those code contributions to POV-Ray 3.7, having made radiosity 
easier to use and all that jazz. Guess what - that's just one facet of 
my life you see. The rest of it is probably neither more nor less 
brilliant than anybody else's (including yours). Struggling with 
depressions myself, BTW - been there, done that. (Well, not publicly 
declaring how dysfunctional I am, but anyway...) So I guess I can say 
with some authority of experience: "If you think you suck, I think 
you're sick." (pun intended)

'Nuff said for now. If you're interested in some further advice along 
these lines, feel free to contact me via electionic mail to Christoph at 
Lipka-Koeln in Germany (de).


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From: Thomas de Groot
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 20 Nov 2011 02:57:12
Message: <4ec8b2d8$1@news.povray.org>

> Of course I know of this... but I would like to create a scene matching
> my *subjective* recalls of bright summer days - even in the
> Mediterranean, I can't remember shadows being THAT blue!

But you sky is *much* bluer than the Mediterranean sky! Look at 
photographs, I think you will see the blue hue in the shadows, 
especially on white walls.

Note also that the blue is tempered by all the colors that are 
reflected/refracted from other objects around.

Thomas


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From: Thomas de Groot
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 20 Nov 2011 03:14:41
Message: <4ec8b6f1@news.povray.org>

should seriously seek more professional help. We all here can certainly 
try to make you see the bright side of life, and we shall, but that is 
not enough. You may need a little extra support. Whatever you may think, 
keep faith in yourself. Something I can advise in the mean time from 
experience, shut down you PC, forget POV-Ray for a while, take your bike 
(if you have one, else put on good walking shoes) and make big tours, 
without exerting yourself unnecessarily, but putting on a good effort. 
Do that for a week. And think of nothing else, least about yourself. Not 
a cure, but a balm.

Thomas


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From: Cousin Ricky
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 20 Nov 2011 20:50:01
Message: <web.4ec9ad244ccf544d85de7b680@news.povray.org>
=?ISO-8859-1?Q?J=F6rg_=27Yadgar=27_Bleimann?= <yaz### [at] gmxde> wrote:
>
> But my learning curve is very, very flat... when I compare myself to
> [snip]

Whoops!  Comparing yourself to others is generally a bad move.

> Am 18.11.2011 19:26, schrieb Cousin Ricky:
>
> > You can do it again.  Just give it more time and effort.
>
> And that's the problem... I'm not used to giving effort (in any fields
> of life) anymore, effort just HURTS!

   Life is difficult.
                              --the Buddha

   This is a great truth, one of the greatest truths.  It is a great
   truth because once we truly see this truth, we transcend it.  Once
   we know that life is difficult--once we truly understand and accept
   it--then life is no longer difficult.  Because once it is accepted,
   the fact that life is difficult no longer matters.
                              --M. Scott Peck, M.D., _The Road Less Traveled_

> And when I try and try and try and
> even the 22nd attempt is the same failure as the first, then I wonder


This is an example of a "cognitive distortion."  See:
   http://psychcentral.com/lib/2009/15-common-cognitive-distortions/

Find a psychologist who practices cognitive behavioral therapy.  Avoid
psychoanalysis.

I personally have been impressed by your determination over the years.  Please
don't give that up!  Take it from someone who's struggled with clinical
depression for 20 years: as hopeless as your situation may *seem* to you today,
you will not always feel this way.


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From: Hildur K 
Subject: Re: Realistic indoor radiosity - I still don't get it!
Date: 13 Jan 2012 10:35:01
Message: <web.4f104dd74ccf544d59029a320@news.povray.org>
> What did I happen to not understand?



You seem to be on the right track. But... well, let me see.

It seems like you forgot to set the material finishes to 0 on your white walls?
Right?
This is the most important step because without it you will never get realistic
bouncing of light off the surfaces.

In that old tutorial I used
finish {
        ambient 0
        diffuse 1

for all materials except the sky sphere.

Sometimes I use diffuse 0.9 or even 0.8 in outdoors situations only, depends on
the situation, but ambient finish should always be 0 when using radiosity.

Another thing, you can never use the same radiosity setting for bot indoors and
outdoors situation. Unless you cheat with fill lights perhaps. But if you want
to mimic real daylight it is not possible. The light on the outside will always
be brighter than the light bouncing inside the room. The outside light is more
direct, while the inside light is mostly indirect. Our eyes will automatically
adjust to this in reality. No camera can take pictures both inside and outside

do it.


inside you have to use two different radiosity settings for each situation.

One tip: try to avoid using colors for surfaces that are 100% white (or 100%
black for that matter) they can never be realistic.

One more thing. The recursion limit of 5 is probably a bit too high for your
scene as you are getting more light in through the windows than in the tutorial.
"recursion limit" controls how many times indirect light bounces off the
surfaces. Where there is little light coming in you typically use higher values
to get more light in you room. Every situation is unique so you may have to try
out a few variations. Too much recursion washes away the contrast, too little
and your scene is too dark. Only do this AFTER you set the material finishes to


Try playing with the balance between "recursion limit" and "brightness".

I usually use recursion limit of 3-5 indoors and 1-3 outdoors.

If you start getting "dirt" or dark smudges on your surfaces, that means you are
on the right track. Those you should be able to get rid of in the final
rendering by raising "count" to 400-600. It takes longer to render but that is
the necessary evil of radiosity.

Hope this helps and happy raytracing.

Hildur K.


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