POV-Ray : Newsgroups : povray.advanced-users : Wood coloring help. Server Time
28 Jul 2024 16:22:04 EDT (-0400)
  Wood coloring help. (Message 1 to 8 of 8)  
From: Gary Blessing
Subject: Wood coloring help.
Date: 24 Aug 2004 05:25:17
Message: <412b097d@news.povray.org>
Hello Folks,

well my hats off to whoever wrote the color maps for the woods in
woods.inc.....
I've been trying to imitate a wood that I've been working with lately called
paduk.
I  found a grain pattern that is verry close in T_Wood14.But modifying the
colors has
proved to be....imposible :-) oh I can modify the colors alright, just not
to what I want...

So....
Could someone give me a hand with this?
its in oranges and orange browns.....
there's a pice of the colorations in this auction(not mine,although I might
buy these pieces)
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=2232355759

Any help apreciated!
Thanks!

G.

--
Gary Blessing

Have Laptop, Will Travel.


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From: Jim Charter
Subject: Re: Wood coloring help.
Date: 24 Aug 2004 10:29:43
Message: <412b50d7$1@news.povray.org>
Gary Blessing wrote:

Maybe a little more on what you see the difference is to be gapped and 
what you have tried

For instance the most noticeable difference to me is the way the large 
grain in your target wood acts more like a ramp_wave with a fairly crisp 
chage in color between extreme light and extreme dark.  Wood by default 
uses a triangle_wave

So I tried these changes:

#declare M_Wood14A =
colour_map {
     [0.00 0.10 color rgb < 0.80, 0.232, 0.115 >
                color rgb < 0.80, 0.232, 0.115 >]
     [0.10 0.90 color rgb < 0.80, 0.232, 0.115 >
                color rgb < 0.45, 0.115, 0.060 >]
     [0.90 1.0  color rgb < 0, 0, 0 >            <<<<<<<<<<<<<<
                color rgb < 0.45, 0.115, 0.060 >]
}

and

#declare P_WoodGrain14A =
pigment {
     wood
     ramp_wave  <<<<<<<<<<<<<<<<<<<<<<<
     colour_map { M_Wood14A }
     turbulence 0.065
     octaves 2
     scale <0.15, .15, 1>
     translate < -1 0 0 >
     rotate <-3, -3, 0>
}


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From: Jim Charter
Subject: Re: Wood coloring help.
Date: 24 Aug 2004 13:26:16
Message: <412b7a38$1@news.povray.org>
Apon rereading your post I see that perhaps it was getting the exact 
colors that was your concern.

When dealing with compound colors like orange I sometimes find it 
helpful to compose macros which isolate how the color is varied, if for 
no other reason than to organize my mind

One such macro I find useful goes something like this:

#macro Desaturate ( Color, Factor )

         #local Compliment = <1,1,1>-Color;
         #local Compliment = Compliment*Factor;
         #local NewColor = Color+Compliment;
         #local Numerator = Color.red + Color.green + Color.blue;
         #local Denominator = NewColor.red + NewColor.green + 		 
NewColor.blue;
         #local NewColor = NewColor*Numerator/Denominator;

         NewColor
#end

This macro is intended to desaturate a color while maintaining its basic 
level of brightness.  Advanced users might wince but I find macros like 
these can help me zero in on a color.


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From: Gilles Tran
Subject: Re: Wood coloring help.
Date: 25 Aug 2004 19:42:34
Message: <412d23ea@news.povray.org>

news:412b097d@news.povray.org...

> Could someone give me a hand with this?
> its in oranges and orange browns.....

The way I work with colours is to sample them from photographs... Of course
it's not that simple, since the colours in the photographs are influenced by
the lighting, but it's a start. In any case, it's amazing how the intuitive
perception we have of colours is different of the actual rgb values.

G.


-- 
**********************
http://www.oyonale.com
**********************
- Graphic experiments
- POV-Ray and Poser computer images
- Posters


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From: miriam english
Subject: Re: Wood coloring help.
Date: 10 Sep 2004 21:35:00
Message: <web.4142561bee57d69538f1caf60@news.povray.org>
"Gary Blessing" <ble### [at] icefognet> wrote:

> I can modify the colors alright, just not
> to what I want...

If you use MSWindows get a wonderful little program called Irfanview
http://irfanview.com (it is free for non-commercial use) and display a
picture of the wood. Now click on the part that you want the color of and
irfanview will show the color codes in the title bar. It is a simple
process to enlarge the image and click on parts of the picture and note
down all the values.

If you use Linux, Gimp has a similar capability.

As Gilles said our eyes are subject to the most amazing set of optical
illusions which make it surprisingly difficult to assess colors.


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From: Mike Williams
Subject: Re: Wood coloring help.
Date: 11 Sep 2004 04:55:49
Message: <JtUeVHAs0rQBFwNq@econym.demon.co.uk>
Wasn't it miriam english who wrote:
>"Gary Blessing" <ble### [at] icefognet> wrote:
>
>> I can modify the colors alright, just not
>> to what I want...
>
>If you use MSWindows get a wonderful little program called Irfanview
>http://irfanview.com (it is free for non-commercial use) and display a
>picture of the wood. Now click on the part that you want the color of and
>irfanview will show the color codes in the title bar. It is a simple
>process to enlarge the image and click on parts of the picture and note
>down all the values.

What I tend to do is to use Irfanview to decrease the number of colours
in the image to something manageable and then use Image=>Export_Palette.
This creates a .PAL file which is an ASCII text file containing three
header lines (Identifier, version, number of colours) then a list of the
RGB values. Grab the list of RGB values and divide by 256.

-- 
Mike Williams
Gentleman of Leisure


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From: Gary Blessing
Subject: Re: Wood coloring help.
Date: 13 Sep 2004 04:23:16
Message: <414558f4@news.povray.org>
Yes,  getting the colors is easy.....I've had irfanview for a while now...
although I didn't know about exporting to a .PAL file...
Its putting them together in the right way in pov code thats the hard part
for me. I got a rather nice blood-wood though...


Gary

"Mike Williams" <nos### [at] econymdemoncouk> wrote in message
news:JtU### [at] econymdemoncouk...
> Wasn't it miriam english who wrote:
> >"Gary Blessing" <ble### [at] icefognet> wrote:
> >
> >> I can modify the colors alright, just not
> >> to what I want...
> >
> >If you use MSWindows get a wonderful little program called Irfanview
> >http://irfanview.com (it is free for non-commercial use) and display a
> >picture of the wood. Now click on the part that you want the color of and
> >irfanview will show the color codes in the title bar. It is a simple
> >process to enlarge the image and click on parts of the picture and note
> >down all the values.
>
> What I tend to do is to use Irfanview to decrease the number of colours
> in the image to something manageable and then use Image=>Export_Palette.
> This creates a .PAL file which is an ASCII text file containing three
> header lines (Identifier, version, number of colours) then a list of the
> RGB values. Grab the list of RGB values and divide by 256.
>
> --
> Mike Williams
> Gentleman of Leisure


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From: David Wallace
Subject: Re: Wood coloring help.
Date: 13 Sep 2004 21:42:22
Message: <41464c7e@news.povray.org>
The eyedropper tool in most paint programs (I use Paint Shop Pro) can be
used for this purpose.  Simply grab the color with the eyedropper and click
on the color swatch, which in PSP is part of the color palette.  This brings
up a color picker window with your color's RGB and/or HSV values already in
the text boxes.  It works for any type of color you want to pluck out.  I
like to use this trick for color matching from digital photographs,
especially of rocks, plants, and fungi.

PSP has an automatic image magifier for precise pixel plucking ;)

"miriam english" <mir### [at] werplenetau> wrote in message
news:web.4142561bee57d69538f1caf60@news.povray.org...
> "Gary Blessing" <ble### [at] icefognet> wrote:
>
> > I can modify the colors alright, just not
> > to what I want...
>
> If you use MSWindows get a wonderful little program called Irfanview
> http://irfanview.com (it is free for non-commercial use) and display a
> picture of the wood. Now click on the part that you want the color of and
> irfanview will show the color codes in the title bar. It is a simple
> process to enlarge the image and click on parts of the picture and note
> down all the values.
>
> If you use Linux, Gimp has a similar capability.
>
> As Gilles said our eyes are subject to the most amazing set of optical
> illusions which make it surprisingly difficult to assess colors.
>
>
>


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