additive on a single layer.

hi guys!

hope there's still some people around this part of forums...

i have a quick, simple question:

is it possible to have an additive effect that only works on a single layer?

im having a hard time figuring it out. basically im using an additive light effect on a layer where characters and environments are, but then i have a background layer behind it and i dont want that additive effect to show on that. any help would be most welcome !

I'm pretty sure you could set "force own texture" on a layer in Construct Classic. Maybe that would help?

It causes the effects of the objects on that layer to only affect that layer.

thanks! i tried additive, but it didnt work the way i wanted. then i tried additive plus and it started working.

BUT:

theres a strange anomaly. i have a quick photo

the small square is on the "character" layer, the bright sphere inside the square is a sprite that has the additive plus effect, but there shouldnt be that sharp outline, its supposed to be a smooth gradient. am i doing something wrong?