Light interior with neon

I am trying to do some sci-fi interior lighting.

I have a directional light with shadows turned off, this is set low. It is pretty dark still (which is what I want)

I would like to light the level with emissive and neon. Emissive materials dont really light much besides themselves in my experience. Any tips or tricks anyone can share to get something cool going, or to better simulate the lighting coming from a neon sign?


I should probably mention this suggestions for lighting a mobile game would be great

Emissive material lighting can only affect static lighting and volumetric lightmaps so if you have something dynamic it will only get that emissive lighting through the volumetric lightmaps. The best way to do it would be to place actual lights around where you have the neon lights to cast the light properly. While it can’t make a complex shape you can at least change the size of placed lights to more closely match the size of your neon lights.

Are you sure that’s still true in .26?
isn’t the reason performance is so bad partially due to the fact that emissive dynamic is now a thing?

Or are we just not gaining anything at all and losing 25 to 50 FPS just because that’s what the big wigs decided???

Also, for anyone in .25
​​​​you can always give LPV a try. It’s not amazing. Brings up a ton of issues and probably requires distance field res to be bumped up on all models. BUT.
it can work at 90fps 4k on a 1080ti if you are willing to spend time at making it look right.

LPV is an option but performance and results with LPV sucks so I wouldn’t go that route especially for mobile.
Otherwise there is no dynamic emissive lighting in UE4 right now, even ray tracing doesn’t do emissive lighting yet (though it will at some point).

This was WAY over my head LOL, but it seems solid. Im okay with faking the neon using standard lighting. I am not concerned with accurate shadows.

I tried using spotlight set to stationary, it looks good in the editor but when I build, it looks like garbage. Significantly less light in the build.

I know spotlights are a little iffy, would it be better to use a different type of light for mobile?


I put a light mass importance volume in the level.

I will do some research into volumetric lighting since I have no idea what that is at the moment

You should go ahead and mess with using regular lights, adjust the radius and length to try and make them about the size of the neon lights and that can come closer to approximating what the light from the neon lights would do.

No there isnt? (by default) Theres ssgi and lpv but ssgi has to be manually enabled and lpv not only is a bit tricky to enable but is on the way out. What your seeing is either baked lighting or bloom.

so they make us pay 25fps or more to bake emissive lighting.

I guess (surprisingly?) That wasn’t a feature before, but its also nearly completely pointless in relation to the low performance…
how was it not a feature though? Have i really been using lpv for over a year? Lol

I wish it was a feature (Though lumen is looking promising) Also, I have no idea where the 30~ fps went, but i want it back.