Inverse Squared Falloff Lighting Bug

After making sure this is a bug, I’ll file a bug report, that’s why I’m posting here first:

I’ve made a fire particle in cascade similar to the one in starter content. It has a Light module and it’s working as intended when the particle is isolated from other fire particles. But with other fire particles the brightness suddenly shoots up and glitches out between being too bright and normal (from one angle its normal, from another its glitched). Here it is:

My settings of Light in cascade.


Light module working when particle is isolated.

Light module not working and being too bright when with other fire particles.

Also, particles don’t need to be this close to glitch out. Spawning 3-4 particles within ~20 meters is enough.

first of all, try to avoid using particle light modules. they use outdated lighting code and are extremely heavy on performance. even 1 can be really heavy, and you are spamming about 62 of them.
its better to create some flicker-light effect in a blueprint with a regular light and combine them with the fire emitter.

This is probably also the reason (though on that regard I can be wrong) why its messing up so badly.

“they use outdated lighting code and are extremely heavy on performance”

Wasn’t aware of that one, thanks for that. I had no issues performance wise (I lowered the spawn fraction) and I use the Light module on many of my particles.
But maybe the amount of Light modules are affecting each other’s inverse falloff function for some reason?

I’ll probably just use one Light module for the whole particle and see if that still has the glitch.