"Basiclife" <nomail@nomail> wrote in message 
news:web.455b03b9bef31fb5291c31dd0@news.povray.org...
>
> Another quick question if I may:
>
> In regards to mapping. Assume I had a checker board shape, I'd like the
> horizontal and vertical lines to act in the same way as lines of lat/long.
>
> Secondly, assume my image was 640x480 (for mapping, not the rendered
> output). How can I rig this so that it is stretched around the equator 
> once
> - as a world map would have to be and covers 90% of the surface top to
> bottom?
>
> I'm assuming I add another pigment to specify colouring for those
> non-covered areas but I can work that out by myself.
>
> thank you in advance,
> Simon
>
Hi Simon,

I'm not sure that this is what you mean by a checker board shape as it's 
more a grid, but the example below uses a simple straight line texture and 
layers it over and over again. First it rotates it around the y axis by 10 
degrees at a time, then it moves it vertically to cover the sphere, giving 
an effect like the lines of latitude and longitude on a globe.

On your second question, I'd recommend just making an image the right size 
in a graphics editor and pasting the 640x480 image into the middle of it. So 
it the image covers 90% of what you need, you'd create a new image 640x532 
and paste your 640x480 image into it, aligning it in the middle of the new, 
larger image.

By the way, it's probably best to create a new thread on the newsgroup for 
new questions because a lot of contributors may have stopped reading the old 
thread when they saw the original question answered. By creating a new 
thread you'll get a bigger audience and you're more likely to get your new 
questions answered quicker, plus you may well get a broader selection of 
different techniques and suggestions to choose from.

Regards,
Chris B.


#include "math.inc"
#declare YourObject = sphere {0,1}

#declare LineTexture = texture {
  pigment {
    gradient x
    turbulence 0
    color_map {
      [0      rgbt <0,1,0,0>]
      [0.001  rgbt <0,1,0,0>]
      [0.001  rgbt <1,1,1,1>]
      [1      rgbt <1,1,1,1>]
    }
  }
  scale 10
}

#declare WireframeTexture = texture {LineTexture}

#local I = 0;
#while (I<180)
  #declare WireframeTexture =
    texture {WireframeTexture}
    texture {LineTexture rotate y*I}
  #local I = I + 10;
#end

#local I = -80;
#while (I<90)
  #declare WireframeTexture =
    texture {WireframeTexture}
    texture {LineTexture rotate z*90 scale 2*y*(1-abs(sind(I)/1.1)) 
translate y*sind(I)}
  #local I = I + 10;
#end

object {YourObject texture {WireframeTexture}}

camera {location <0,2,-2> look_at 0}
light_source { <100, 1000, -2000> color rgb 1}

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