Alain <aze### [at] qwertyorg> wrote:
> If you multiply with a map whose values go from 0 to 10, values under 1 
> will darken, while values larger than 1 will brighten. It's just a 
> question of applying some offset or stretching the range of your light map.

> Same with addition, here, you need negative values to darken things.

  This assumes that the lightmap texel components are floating point values.
It is completely unclear to me whether OpenGL and rendering hardware supports
floating point components in textures. There are some indications that at
least some don't. (You can give OpenGL a texture in floating point format,
but it will be internally converted to an 8-bits-per-component bitmap,
clamping all values to the range [0.0-1.0] and multiplying by 255.)

-- 
                                                          - Warp

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