premultiplied on or off??

[Gijs]

When adding a decal bitmap with alpha channel, should I turn premultiplied on or off by default? I ask, because I noticed that lightmap seems to be misled when premultiplied is on.

This image shows what I mean: around the bitmap, the lightmap shows brighter than it should.

[egz]

That depends on if the image is saved premultiplied or not. If you get bright edges with premultiplied the image probably has a straight alpha, not a premultiplied.

[Gijs]

Thanks Torgeir, you explaination clears all my questions (regarding this)