Slope maps can create great wood textures. Warp posted an excelent example
some time ago.

Mick

I hope he won't mind if I republish it here

box{-3,3
    texture
    { pigment
      { wood color_map
        { [0 rgb <.9,.5,.2>]
          [1 rgb <.7,.4,.1>]
        }
        turbulence .5 file://was .3
        scale <.3,1,1>
      }
      normal
      { average normal_map
        { [1  wood .2 slope_map
              { [0 <0,0>]
                [.2 <0,0>]
                [.3 <.5,1>]
                [.5 <1,0>]
                [.7 <.5,-1>]
                [.8 <0,0>]
                [1 <0,0>]
              }
              turbulence .1 file://was 0
              scale <.3,1,1>
          ]
          [1  gradient x 2 slope_map
              { [0 <0,2>]
                [.05 <1,0>]
                [.95 <1,0>]
                [1 <0,-2>]
              }
              turbulence.025
          ]
        }
      }
      finish { specular .3 reflection .1 }
    }
    rotate<45,15,0>
}

"ingo" <ing### [at] homenl> wrote in message
news:8F7378CEseed7@204.213.191.228...
>   When making wood textures I always run into the same problem. The wood
> pattern is too regular. Turbulence seems to make it irregular but not in
> the way real wood is. There are a few problems with the current wood:
>   The constant size of the year rings. On a real tree they vary in size.
> The summer part of a ring is wider than the winter part and each ring
> (summer+winter) also varies from year to year.
>   A tree is not round. Depending on the circumstances it grows in, it gets
> it shape. If the wind is blowing always from one side, the tree will grow
> extra wood on the opposite side. The shape will be more triangular or has
> three or more lobes. Also a tree can be "getordeerd" (don't know the
> English word, it is as if you fix the roots at their position and rotate
> the crown of the tree a few times around z-axis).
>   Is there a way to create a better pattern with an isosurface? an
> somebody point me in the right direction, I lack the math ablility to
> figure out something that works.
>
> Ingo
>
> --
> Photography: http://members.home.nl/ingoogni/
> Pov-Ray    : http://members.home.nl/seed7/

Post a reply to this message