Hello, all.

I've been messing about with Ron Parker's pattern image type to make me some
quick heightfields in MegaPOV 0.6a, and something caught my eye.

The heightfield in the attached image was made up from the following code:

height_field {
  pattern 1000,1000 {
    hf_gray_16
    dents
    colour_map {
      [0.0 rgb 0.0]
      [0.4 rgb 0.0]
      [0.5 rgb 0.1]
      [0.6 rgb 0.8]
      [0.7 rgb 1.0]
      [1.0 rgb 1.0]
    }
    scale 0.25
  }
  pigment {gradient y colour_map {[0 rgb <1,0,0>] [1 rgb <0,0,1>]}}
  translate <-0.5,0,-0.5>
  scale <200,20,200>
}

Looking at the resulting image, it appears that the graduations between the
different greyscales in the colour_map are linear, rather than nice and
smooth in a spliney sort of way.

This right?  Only asking because it seems to go against what's said in the
help file: 'Most of the color patterns do not use abrupt color changes of
just two or three colors like those in the brick, checker or hexagon
patterns. They instead use smooth transitions of many colors that gradually
change from one point to the next.'

Bye,
Alan.

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Download 'colour_map.jpg' (4 KB)

Preview of image 'colour_map.jpg'