6.1.3 Image Maps

  pigment {
    image_map { [TYPE] FILENAME [MODIFIER] }
  }

Where TYPE is any of gif, tga, iff, ppm, pgm, png, jpeg, tiff and sys, FILENAME is the name of a corresponding graphic file.

The colors of the graphic file fill the unitsquare in the $x$-$y$-plane and all parallel planes repeatedly except once is used as MODIFIER. This way of mapping the image to the points in space may be changed by using map_type T instead of TYPE, where $T$ can be

0

planar

1

spherical

2

cylindrical

5

toroidal

Another MODIFIER is transmit all T and filter all F which makes the image partially transparent by the amount $T$ or acting as a filter by the amount $F$. For graphic files using a palette also transmit IDX T and filter IDX F can be used to make only pixels with color index IDX transparent.