Negative lights. I need them.

I have seen ue4 threads that say setting the light brightness to a negative number via blueprint will allow you to get nagtive light. However, in 4.19 this does not work.
I really need negative lights for faking some large scale, realtime AO.
Does anyone know how i can get them in UE 4.19?

Sounds like something that would require some C++ tomfoolery. Have you considered using masks or decals with high roughness instead?


I don’t remember the exact settings but I remember by mistake I had it once with a particle system + volume material…

Pls, they should put this back. For lighting artist, this is very important. Lighting is very complex and implementing it would be easier with unconventional tricks or workflow, everything doesn’t have to be how light works in the real world.
In ue4, one should be able to turn off lights but keep the shadows from those lights. This could be used to achieve indirect shadows especially for animated mesh indoors.
It’s the same way some renderers removed light linking. Thankfully, ue4 has added back lighting channels. For those of us who understand lighting to a certain degree, these tricks/workarounds should be put back, they enable prefect lighting to be achieved easily.

the tricks/workarounds help in those situations so yeah why not have them back
however needing them in the first place seems like a bad approach, so why not request better lighting while we’re at it :smiley:

if I understood correctly you need to block lights from coming through specific areas, is that correct?
usually shadows do the job at that, but for the Skylight it doesn’t really work. if this is your case maybe this will be interesting for you: Localized-IBL implementation - Rendering - Unreal Engine Forums

In Cryengine negative lights simply darken the localized IBL probes. Local probes already respect the environment in terms of ambient lighting. In UE4 however, they should be darkening skylight. But skylight by itself is totally not an acceptable source of ambient light so negative lights would do very little good here as you’d need hundreds of negative lights to battle that purely uniform ambient light all across the game world.

Any chance for a controlled light especially for indoors that controls light and shadow intensity separately? U can tweak the intensity of light from zero to a specific vaule, likewise with shadows. Then bluring the shadows as well to fake soft shadows. I don’t see how it would hurt to include this for lighting artists while the physically accurate stuff is being developed. With this, dynamic indirect shadows can be done fast and easy.
I have always said, renderers don’t have to be ultra realistic to get realistic results. Once u understand lighting to a certain degree, the end result can be achieved without everything being real world like because there are several conditions that contribute towards making surfaces look the way they do.
@Chosker Nice project. That’s very interesting.

Does anyone know if this has been implemented as a plugin:…ing-blueprints

This tutorial was made in 2016. Has there been any implementation of a plugin since then or do I have to follow this from scratch?

Can I use Negative Light now?
Even if you put a negative value in Intensity,
it seems to be treated as 0.