to get hexagons to wrap around a sphere, i think you need megapov's uv
mapping.  that's just a guess.  maybe someone with better knowledge will
comment.

CreeD wrote:
> 
> Hi.  I'm looking to make a soccer ball-like object that combines
> two functions into one isosurface:
> A: the ball
> and B: The hexagons on the ball. I want these hexagons to be raised, which
> is why
> I'm using an isosurface and not a sphere with a function as a surface
> normal.
> 
> In addition I'm trying to use random numbers to generate random hexagon
> colors
> on this ball.
> 
> Can someone tell me what's wrong with this code?  I have several problems
> that have stumped me.
> 
> 1. Both the hexagon pigment and the isosurface function"FHexagon" tend to
> create
> the hexagons asymmetrically, so that at the poles of my sphere there are
> hexagons,
> and these "extrude" downwards along the y axis to the opposite pole. I'd
> like
> hexagons all around the equator as well.
> 
> 2. If I use a rounded box instead of a sphere
> (function "rounded_box" <3> gets me a sphere)
> the pigment seems to map a little more normally, but the isosurface
> function still looks wrong and keeps 'cubing' my sphere to boot. My
> temporary fix is to just contain it with a sphere instead of a box.
> 
> 3. The pigments in my hexagon pattern (which are semi random) seem to
> affect whether the isosurface shows up at all and change the shape.  I
> guess I should declare one pigment for the function and a different one for
> the texture, but if I can work around this I'd like to.  In any case, I
> seem to remember a page with a tutorial on how to make a pigment 3D, and
> the example used was a crackle pattern made into an isosurface function and
> then added to a sphere function to get a crackly sphere.  How does that
> work? (and what happened to the page?)
> 
> code below:
> 
> #declare PHexagon =
> pigment {hexagon
>   color rgb <2,2,2>+10*rand(RandColor)
>   color rgb <2,4,2>*rand(RandColor)
>   color rgb <1,2,4>-rand(RandColor)
>         }
> 
> #declare FHexagon = function {pigment {PHexagon}}
> 
> #declare FRBox = function {"rounded_box" <3>}
> 
> #declare FBoxSurface =
> function {FRBox
>          |    FHexagon(x,y,z)*10
> //The or bar is there because "+" and "&" never seem to work...
>              }
> 
> isosurface {
> 
>      function {FBoxSurface}
> 
> contained_by {sphere {<0,0,0>,3}}
> //but what I really want is a box so you can see
> //the hexagon ridges...
> 
> eval     threshold  5     method 2
> //tweaking the threshold helps make it visible, but not correct ...
> 
> texture {
>  pigment{function{FHexagon}
>   color_map {
>    [0 color rgbf<rand(RandColor)*rand(RandColor),
>                rand(RandColor),
>                rand(RandColor),0>]
>    [.3 color rgbf<rand(RandColor).4,
>                rand(RandColor)^2,
>                rand(RandColor)*rand(RandColor),0>]
>    [1  color
> rgbf<rand(RandColor)+.5,rand(RandColor)+.3,2*rand(RandColor)^2+.5,0>]
> 
>    }//end color map
>   }//end pigment
> //normal {function {FHexagon(x*10,y*10,z*10)*10}scale 10 rotate x*-90}
> //The normal looks okay but it's not what I want.
> }//end texture
> finish {phong 1 phong_size 2 ambient .2}
> rotate x*90} //end iso

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