OK, I've had POV-Ray for a couple months now and played around with it
and pretty much figured out most of its features. There's just one thing
that I still don't get at all. That's color maps. I've read all the docs
and am still completely lost. If anyone out there could offer ANY help,
it would be greatly appreciated. Also, I'm unclear on the capabilities
of a color map. For example, could I make like a label for something
based on a color map rather than using an image map, and if so, how?
Thanks.

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Richard wrote:
> 
> OK, I've had POV-Ray for a couple months now and played around with it
> and pretty much figured out most of its features. There's just one thing
> that I still don't get at all. That's color maps. I've read all the docs
> and am still completely lost. If anyone out there could offer ANY help,
> it would be greatly appreciated. Also, I'm unclear on the capabilities
> of a color map. For example, could I make like a label for something
> based on a color map rather than using an image map, and if so, how?
> Thanks.

I don't have time right now to go into detail on using color maps
but if you go to the povray.text.scene-files directory you will
find a recent post from me listing web sites with pov-ray tutorials.
There are  couple of those sites listed that have tutorials on
using pigments and color maps. I'm hoping to write a tutorial on
the subject in the nest month or so but as things go I haven't
started and it doesn't solve your current problem.

  Will it help any to say that it's so complicated there is no way
to cover everything ?

 There are not only the issues involved with structuring the color
map but for each pattern type the rules of usage change. One would
think that the same color map would work in any pattern type but
the results are unpredictable because the different patterns evaluate
the slope of the color depending upon whe wave type of the pattern used.

It really is an aquired skill and not something that is learned over
night. A good sense of color control is also needed. If you are poor
at designing your own colors you never will get good control of color
maps. If this is so download my improved kolors.inc file form
http://twysted.net it is in the pov objects collection. It has over
650 predefined colors that are easy to copy and paste into color maps
and there is a .pov file that when rendered has and indexd pallet that
corresponds to the colors in the kolors.inc file. 

  As far as making lables proceeduraly it depends on what you want
to do. A possible method would be to use the pov text object, csg it
into another object like a box, and then csg this construction into
the object the label is to be applied to. There are tricks along
the way and I don't have a ready example handy. If I get time tonight
I'll put something together for you.

For most situations you will find that image maps are not only easier
because of the infinite availablity of material to choose from but
they are also much faster than other methods to render and apply.
A large(480x360 is good} high quality image is manditory for good
results and little images render poorly.

Hope this helps a little. I'll try to get you that example tonight
and keep posted for that tutorial in a month or two.

-- 
Ken Tyler

tyl### [at] pacbellnet

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Richard <dai### [at] mindspringcom> wrote:
: OK, I've had POV-Ray for a couple months now and played around with it
: and pretty much figured out most of its features. There's just one thing
: that I still don't get at all. That's color maps. I've read all the docs
: and am still completely lost. If anyone out there could offer ANY help,
: it would be greatly appreciated.

  Render and study this. Perhaps it will help a little:

camera { location -z*3 look_at 0 angle 35 }
light_source { -z*100,1 }
box
{ 0,1
  pigment
  { gradient x color_map
    { [0 rgb <1,0,0>]    // The color map starts from red
      [.5 rgb <1,1,0>]   // goes to yellow
      [1 rgb <0,1,0>]    // and ends to green
    }
  }
  translate -.5
}

: Also, I'm unclear on the capabilities
: of a color map. For example, could I make like a label for something
: based on a color map rather than using an image map, and if so, how?

  Color maps are used to define the colors along a pattern type. In the
example above the pattern type is 'gradient'. The pattern goes from 0 to
1 and the color map specifies what colors are used which each value (all the
in-between values are interpolated).
  The color map doesn't specify the shape of the pattern, only the colors
used.

-- 
main(i){char*_="BdsyFBThhHFBThhHFRz]NFTITQF|DJIFHQhhF";while(i=
*_++)for(;i>1;printf("%s",i-70?i&1?"[]":" ":(i=0,"\n")),i/=2);} /*- Warp. -*/

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