Mike Williams <nos### [at] econymdemoncouk> wrote:
> When I want to grab loads of colours from something like a cloudscape I
> convert the image to a GIF, load it into IrfanView and export the
> palette in PAL format.
>
> In PAL format you get an ascii file with three lines of junk, then a
> list of the RGB values of each palette entry. If you tweak the file by
> inserting commas everywhere, you can #read the data with POV, divide by
> 255 and populate a colour_map.
>
> --
> Mike Williams
> Gentleman of Leisure

That is absolutely brilliant. One thing I have always hated is sitting there
building color_maps by hand. You have truly earned your title, "Man of
Leisure." Thanks for the tip.

//Dave Dunn - hos### [at] aolcom
#local D = union { torus {1,.1 clipped_by {plane {-x,0}}} sphere
{<0,0,1>,.1} sphere {<0,0,-1>,.1} cylinder {<0,0,-1>,<0,0,1>,.1} pigment
{rgb .8} finish {ambient .5 reflection {.5}} rotate x*-90 translate
<-.5,.5,5>} object {D} object {D translate <.5,-1,0>} plane {y,-2 pigment
{checker rgb 1, rgb 0 scale 5} finish {ambient .5}}

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Wasn't it Dave Dunn who wrote:
>Mike Williams <nos### [at] econymdemoncouk> wrote:
>> When I want to grab loads of colours from something like a cloudscape I
>> convert the image to a GIF, load it into IrfanView and export the
>> palette in PAL format.
>>
>> In PAL format you get an ascii file with three lines of junk, then a
>> list of the RGB values of each palette entry. If you tweak the file by
>> inserting commas everywhere, you can #read the data with POV, divide by
>> 255 and populate a colour_map.
>>
>> --
>> Mike Williams
>> Gentleman of Leisure
>
>That is absolutely brilliant. One thing I have always hated is sitting there
>building color_maps by hand. You have truly earned your title, "Man of
>Leisure." Thanks for the tip.

I must confess that the technique is not entirely original with me. It's
commonly used to produce colour maps for fractals with programs like
Fractint or Ultrafractal. In fact a Fractint .MAP file looks very much
like an IrfanView .PAL file with the first three lines deleted. I just
spotted that you can do the same thing with POV, with a bit more
processing.

-- 
Mike Williams
Gentleman of Leisure

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Mike Williams <nos### [at] econymdemoncouk> wrote:
> I must confess that the technique is not entirely original with me. It's
> commonly used to produce colour maps for fractals with programs like
> Fractint or Ultrafractal. In fact a Fractint .MAP file looks very much
> like an IrfanView .PAL file with the first three lines deleted. I just
> spotted that you can do the same thing with POV, with a bit more
> processing.
>
> --
> Mike Williams
> Gentleman of Leisure

Funny how synchronicity works. Just after I read your post, I was reading
some other stuff about blending image maps and procedurals on the same
object. This technique would be perfect in terms of assuring continuity
between the colors.


//Dave Dunn - hos### [at] aolcom
#local D = union { torus {1,.1 clipped_by {plane {-x,0}}} sphere
{<0,0,1>,.1} sphere {<0,0,-1>,.1} cylinder {<0,0,-1>,<0,0,1>,.1} pigment
{rgb .8} finish {ambient .5 reflection {.5}} rotate x*-90 translate
<-.5,.5,5>} object {D} object {D translate <.5,-1,0>} plane {y,-2 pigment
{checker rgb 1, rgb 0 scale 5} finish {ambient .5}}

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"Orchid XP v2" <voi### [at] devnull> wrote in message
news:426a5b6a@news.povray.org...
>
> Hmm... never ever tried doing that... (Although I do remember somebody
> tried using lights with negative RGB values to see what would happen.)

i did a reflection with a negative exponant value and it was kinda weird.
not pretty, just weird :)

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