POV-Ray : Documentation : 1.2.5.3 Creating Color Patterns
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1.2.5.2 Adding Bumpiness   1.2.5.4 Pre-defined Textures

1.2.5.3 Creating Color Patterns

We can do more than assigning a solid color to an object. We can create complex patterns in the pigment block like in these examples:

  sphere {
    <0, 1, 2>, 2
    texture {
      pigment {
        wood
        color_map {
          [0.0 color DarkTan]
          [0.9 color DarkBrown]
          [1.0 color VeryDarkBrown]
        }
        turbulence 0.05
        scale <0.2, 0.3, 1>
      }
      finish { phong 1 }
    }
  }

  sphere {
    <0, 1, 2>, 2
    texture {
      pigment {
        wood
        color_map {
          [0.0 color Red]
          [0.5 color Red]
          [0.5 color Blue]
          [1.0 color Blue]
        }
        scale <0.2, 0.3, 1>
      }
      finish { phong 1 }
    }
  }

The keyword wood specifies a pigment pattern of concentric rings like rings in wood. For every position in POV-space, a pattern returns a float value in the range from zero to one. Values outside the zero to one range are ignored. The color_map specifies what color vector is assigned to that float value. In the first example the color of the wood blends from DarkTan to DarkBrown over the first 90% of the vein and from DarkBrown to VeryDarkBrown over the remaining 10%. In the second example the colors do not blend from one to an other, but change abrupt. The turbulence keyword slightly stirs up the pattern so the veins are not perfect circles and the scale keyword adjusts the size of the pattern.

Most patterns are set up by default to give us one feature across a sphere of radius 1.0. A feature is very roughly defined as a color transition. For example, a wood texture would have one band on a sphere of radius 1.0. In this example we scale the pattern using the scale keyword followed by a vector. In this case we scaled 0.2 in the x direction, 0.3 in the y direction and the z direction is scaled by 1, which leaves it unchanged. Scale values larger than one will stretch an element. Scale values smaller than one will squish an element. A scale value of one will leave an element unchanged.

More about "wood"

More about "turbulence"

More about "scale"

1.2.5.2 Adding Bumpiness   1.2.5.4 Pre-defined Textures


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