Some applications may require a different illumination map for different kinds of materials.
Up to three illumination maps can be authored for each vignette. The illumination map for a render operation is selected with the
illum= and or
Default selection - If
gloss= are not specified, the renderer uses the first authored illumination map (typically map A, aka the ‘Flat’ illumination map).
Automatic selection with
gloss= - If
illum= is not specified or is set to
-1, the renderer compares the specified
gloss= value with the gloss values associated with each illumination map in the vignette. It chooses the illumination map whose gloss value is closest to the specified
Explicit selection with
illum= - If
illum= is specified and set to
2, the renderer uses the corresponding illumination map;
gloss= is ignored for selecting the illumination map.
If the vignette contains only one illumination map, the renderer uses that map and ignore the