Equivalent of "Screen" After Effect's blend mod for Blender?

I have footages of fog that i would like to include to my scene in Blender but they have a black background.
So when i add them to Blender with “import an image as plane” there’s still this black background and that’s not usable. In After Effects we can ust get ride of it by choosing “Screen” in the blend mod of the layer.

Is there a way to do the same thing in Blender, to can use the fog texture without the black background?

The normal way would be to convert the black to alpha in gimp or photoshop, than images as plane would work.
Otherwise you have to change the material and convert the black to alpha in the material and set the blend mode.

black_to_alpha.blend (798.8 KB)

1 Like

Have you tried using a mix node and setting it to “screen” or “add”?
It depends a bit on what you want to do. Add simply adds the value of each pixel to the image bellow. Screen is a bit more complicated and does a whole bunch of stuff.
The gimp manual is a good source for looking up what each mode does. AFAIK the modes work the same im Blender and - i believe - other apps such as PS.:

For fog I would say “add” makes more sense than “screen” but perhaps for this specific case “screen” is better.


1 Like

@Lumpengnom & @rigoletto with the help of you both and some tries i found the nodes combinaison that permit to make this background disappear while having control on the transparency / intensity of the fog. Just some colorRamp and Math nodes set to add. Playing with nodes sometimes feels being an alchimist trying things and suddenly finding the good recipe.

Ah, you used math nodes. I meant mix nodes but for this purpous math nodes are probably better.

Instead of the ramp and the math add mode it might make sense to simply use a math multiply node in there. You can also combine it with a ramp of course. The advantage is that your black parts allways stay completely black.
Sticking an rgb curve in there could also be a good eay to control it.

1 Like

Yes i firstly tried mix nodes and it didn’t worked at all in this case.
I just tried to replace by a multiply and yes that’s even better, it give more control to the fog intensity without affecting the whole layer. Thanks a lot!