RusHHouR <gee### [at] mailnu> wrote:
> I would very much appreciate any suggestions on the subject,
> cuz I know it can be done... I've seen it...

  Here are some tips for creating decent-looking wood textures:

1. The 'wood' pattern consists simply of concentric circles ramp wave
   around the z axis. All by itself it's a bit boring for a "wood" pigment.
   However, it has a great turbulence implementation which makes it look
   superb. Try with different turbulence amounts.

2. Scale the 'wood' pigment unevenly so that it's elongated along the
   z axis (or whatever axis the circles are around if you have rotated
   the pattern). This matches real-life wood a lot more closely.

3. While some woods have smooth color transitions, most of them have
   quite sharp transitions between layers of colors. Take this into
   account in your color map.

4. If you want rough non-polished wood, use a normal pattern which is
   also elongated along the same axis as the pigment. This normal can
   exactly match the pigment (by applying the exact same transformations
   and turbulence), but it doesn't have to.

  This small scene tries to demonstrate these principles:

#declare UseNormal = no;

camera { location -z*10 look_at 0 angle 35 }
light_source { <10, 5, -20>, 1 }

cylinder
{ -y*2, y*2, 1

  pigment
  { wood color_map
    { [0 rgb <1, .8,.5>]
      [.4 rgb <.95, .7, .4>]
      [.6 rgb <.75, .5, .2>]
      [1 rgb <.7, .4, .15>]
    }
    turbulence .5
    rotate x*90
    scale <1, 20, 1>*.25
  }

  #if(UseNormal)
    normal
    { wood -.25
      slope_map { [0 <0,0>][.5 <.5,1>][1 <1,0>] }
      turbulence .5
      rotate x*90
      scale <1, 20, 1>*.25
    }
  #end

  finish { specular .25 }
}


-- 
                                                          - Warp

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