On Wed, 2007-03-21 at 09:39 -0700, Esben Jannik Bjerrum wrote:
> Is it possible to use additive mixing of transparent objects. Im
> not sure if I use the correct terminology, but I mean like mixing
> colored light and not colored paint, so that a green transparent
> object overlaying a red one will be yellow and not brownish? Or do
> this exceed the SVG format? The mixing seem to be somewhere in between
> the two possibilites?
The normal SVG blending mode is essentially a weighted average based on
the alpha of the object. So, with 50% transparency, rgb(0%, 100%, 0%)
over rgb(100%, 0%, 0%) comes out to rgb(50%, 50%, 0%).
It's possible that the <feComposite> filter primitive could be made to
do what you want, although Inkscape doesn't support it yet.