POV-Ray : Newsgroups : povray.binaries.images : POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 by Eric Freeman Server Time
28 Mar 2024 22:03:15 EDT (-0400)
  POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 by Eric Freeman (Message 21 to 30 of 33)  
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From: Melody
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 16 Nov 2019 16:05:00
Message: <web.5dd061b9829921489da690110@news.povray.org>
Alain Martel <kua### [at] videotronca> wrote:
......
> adaptive 0 start with 4 samples (2 by 2): One at each corners.
> adaptive 1 start with 9 samples (3 by 3): Each corners plus one in the
> middle of each side and the center.
> adaptive 2 start with 25 samples (5 by 5), adaptive 3 with 81 (9 by 9),...
>
> This allow you to use something like this :
>
> area_light 3*x 3*z 1025 1025 adaptive 0
>
> and still have reasonably quick renders with no discernible banding,
> even without jitter.
>
> If you use an area_light of 4x4 with jitter and antialiasing, then the
> banding will disappears but your render time will greatly increase
> because all pixels in the penumbra will get antialiased.

code for chessdiff2 ---
+AM2 +A0.3
board_sq(<-3+j,0,-3+i>),so dimensions are: 3 * 8 = 24 and the frame.
#if (Area_Light)
  area_light x*15, y*15,6,6
  adaptive 1 jitter orient circular
#end
32 shadows takes 21 hrs. yikes!

during which time I surmised 4,4 would be enough, but it takes so long to check
these things. but 1025x1025, I cant even multiply that in my head, unbelievable
N lights = 1050625 = a million lights? seriously?

in chessdiff.png 13,13 - u can see the shadow streaks, which disappeared in
chessdiff2.png

so your saying, use a million lights, but adaptive 0 ?


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From: Melody
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 16 Nov 2019 16:10:00
Message: <web.5dd064b9829921489da690110@news.povray.org>
"jr" <cre### [at] gmailcom> wrote:
> I would like to walk on water, just like you.  what is your secret?  ;-)

learn how. collect examples of well lit scene scripts that run, ask for them to
be posted when u see them, some people are very helpful that way. follow
examples, til u know enough. read that help file. it helps.


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From: Melody
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 16 Nov 2019 23:55:00
Message: <web.5dd0d284829921489da690110@news.povray.org>
"jr" <cre### [at] gmailcom> wrote:
> I would like to walk on water, just like you.  what is your secret?  ;-)

also F1 fails with pov3.7 and windows7. you need F1.
if u don't understand a word or a number, place cursor, hit F1. pay attention
and learn.

more versions = not 3.7
http://news.povray.org/povray.binaries.utilities/thread/%3Cweb.5dd0cb2054a09c79da690110%40news.povray.org%3E/


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From: Melody
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 17 Nov 2019 00:50:00
Message: <web.5dd0de2f829921489da690110@news.povray.org>
i dont get it or the help file is inconclusive !!

AXIS_1_VECTOR, AXIS_2_VECTOR, Size_1, Size_2

referring to "size"
"There is no point in using circular with linear area lights or area lights
which have a 2x2 size."
.. .
.. .     that's already circular.
suggesting "size" = n lights.
and the vector length = array dimensions

so I'm still not sure, also it to alludes to adaptive n = n lights.


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From: Melody
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 17 Nov 2019 01:10:00
Message: <web.5dd0e3c3829921489da690110@news.povray.org>
this line seems conclusive. yes, size == n lights according to this.

"For example area_light x,y,4,4 specifies a 4 by 4 array of lights. If you
specify adaptive 3 it would mean that you should start with a 9 by 9 array. In
this case no adaptive sampling is done. The 4 by 4 array is used.
"
so back to my original question, a million lights, seriously?


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From: Melody
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 17 Nov 2019 01:20:01
Message: <web.5dd0e5a2829921489da690110@news.povray.org>
adaptive 0 is still 2x2 (at least)
adaptive 0 does not mean off.
apparently


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From: Melody
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 17 Nov 2019 01:50:00
Message: <web.5dd0ecf5829921489da690110@news.povray.org>
updated chessdiff.pov with comments on area_light
  area_light x*15, y*15,3,3
//understate rows and columns, turns off adaptive sampling = not enough lights
// adaptive 0 = 2x2 - 1 3x3 - 2 5x5 - 3 = 9x9


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From: Bald Eagle
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 17 Nov 2019 09:00:02
Message: <web.5dd1513e829921484eec112d0@news.povray.org>
There are too many references scattered all over the place.

Try this:
http://wiki.povray.org/content/Reference:Light_Source

and maybe increase global ambient illumination if you need "more light".

Sometimes one can spend a whole day doing nothing but playing with lighting.


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From: Bald Eagle
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 17 Nov 2019 09:05:01
Message: <web.5dd152c9829921484eec112d0@news.povray.org>
Alain Martel <kua### [at] videotronca> wrote:

> When using area_light you should always use adaptive.
> The PRESENCE of adaptive turn the feature on. adaptive 0 DO NOT turn it off.
>
> adaptive 0 start with 4 samples (2 by 2): One at each corners.
> adaptive 1 start with 9 samples (3 by 3): Each corners plus one in the
> middle of each side and the center.
> adaptive 2 start with 25 samples (5 by 5), adaptive 3 with 81 (9 by 9),...
>
> This allow you to use something like this :
>
> area_light 3*x 3*z 1025 1025 adaptive 0
>
> and still have reasonably quick renders with no discernible banding,
> even without jitter.

The details of how area_light actually works is a bit murky to those of us who
don't use it enough or have investigated it in a string of experimental renders
or reading the source code.

In any event, I'm sure Alain isn't suggesting using a million lights.
Due to however area_light works, that 3x3 patch might get split up into a grid
of a million squares - but it doesn't take the same amount of time to render as
a million separate point lights.


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From: Dick Balaska
Subject: Re: POV-Ray Archaeology: Yet Another Chess Set, 1998-12-15 byEricFreeman
Date: 17 Nov 2019 13:23:07
Message: <5dd1900b$1@news.povray.org>
On 11/17/19 8:55 AM, Bald Eagle wrote:

> 
> Sometimes one can spend a whole day doing nothing but playing with lighting.
> 

Matt Damon just told this story on the Bill Simmons podcast:

Kubrick had a model of the Overlook Hotel on a table, and while 
producers and gophers stood around, spent over a week just walking 
around it setting up miniature lights, photographing it, moving lights, 
repeat, for a week.

When he was satisfied, he mathematically scaled up the lights for the 
real production of The Shining.

-- 
dik
Rendered 24,503,731,200 of 40,928,716,800 pixels (59%)


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