I have a simple scene with a box, ambient light (color 0.5f), directional light (color 0.5f) and a DirectionalLightShadowFilter (though the problem is the same with a renderer).
The problem is that the shadow seems to affect also the color contribution from ambient light, which seems to be strange for me. Is this behavior correct? In my opinion, the color from ambient light should be “added” after the shadow, i.e. the shadow should only “cancel” the color contribution from the directional light.
This behavior also leads to the strange behavior that when having directional light of color (0,0,0,1) and ambient light of color 1, there are still shadows with full intensity.