Negative Lighting (Unity 2017+)


So I’m sitting with a bit of a peculiar situation. I’m working on a game that has a heavy emphasis on light and dark. Now, adding light - as we know is simple, it uses additive blending and creates a brightness around the light source, but what about using subtractive blending to create a darklight that “saps” light away. I’ve been digging through old threads, but most of them are several years old, and what I’ve described above was achievable in unity 5.x using deferred rendering but since the release of 2017.x this no longer seems possible.

I don’t have much experience coding shaders, so I could really do with some help. Does someone have some information they can point me to, or a possible a workaround script to create this “darklight”? Any help would be much appreciated. Thanks!

Okay so my current workaround is using Aura ( an opensource volumetric lighting framework to create a black volumetric sphere with a falloff. The effect is close to what I was looking for but is not viable for mobile.

So for anyone else who comes here with the same question - it seems like it’s not possible in the current build of unity to use subtractive lighting (again, I might be wrong and I really hope I am) so give the above workaround a try.

If anyone does get subtractive lighting to work in unity 2017.x please comment! (Or even in a newer version of unity, I’m sure there will be others who appreciate the answer - myself included.)

Good luck guys!