hundreds of lights simulation

Hello everyone,

I am developing a demo scene for the Oculus rift , the scene involves lots of panels with hundreds of small lights that switch on and off randomly…
what would be the best ( as in rendering efficiency ) way to handle this with UE4? real lights? animated maps? vertex colors? ( I need some light bleed on the surrounding panel surface), or maybe swapping
whole mesh with backed illumination on them…any insight? thank you!:slight_smile:

You can easily do something with an emissive texture, if they’re small and don’t actually need to emit light on anything then that can work just fine.

Thanks for the hint, I cannot test right now, but the emissive texture will bleed light onto the surface surroundings? would be perfect if it works and it’s not heavy … I will try later on!

Emissive as darthviper107 would probably be the cheapest method, but you can check with the profiling tool built into UE4. Instead of leaning on the emissive alone, boost your bloom to simulate light bleed.

Emissive won’t cast light, it just makes part of the material glow, so if you have something like say a button on a control panel that you want to light up, then it can make it glow, but if you were to put your hand near the button it wouldn’t cast any light on your hand.
The engine can support many non-shadow casting lights at once, but if you have a lot of them, then you wouldn’t want to place them all by hand, so if it’s not super important that they actually cast light then you can do it with emissive textures.

I personally would start out with trying movable lights and no shadow casting to see how well the deferred render handles it.
Second method to try out would be stationary lights, shadows and light attenuation are baked in while light intensity and color can still change dynamically.
And there is the emissive material option as others have suggested.

A more complex option would be to use lights and emissive materials and using a blueprint that can switch between the two methods based on distance. That way you get nice quality lighting up close while faking it in the distance.


thank you everyone for the ideas, I will try them out soon, the project I’m working on is this one :

in case you don’t have access I post one render just to show what the goal is :


I will keep you posted with UE4 screenshots as soon as I’ve got some :slight_smile:


Yeah, for that type of thing an emissive texture will work just fine, there’s different ways you can animate in a material but you can also animate a material using some parameters and Matinee