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Lighting | Dynamic Global Illumination [Spotlight]

DYNAMIC GLOBAL ILLUMINATION

28 JULY 2017:
I’m happy to announce that the product is out on the marketplace.

Marketplace Link: https://www.unrealengine.com/marketplace/realtime-global-illumination-spotlight

https://youtube.com/watch?v=fZnpaPYzWWU

Hi everyone :smiley: today I want to show you this solution that I made in blueprint to achieve dynamic global illumination with a spotlight, it has three modes: 1. Off 2. Simple 3. Advanced; the main difference between Simple and Advanced is the color bleeding, if you don’t know what that is, just watch the video and pay attention around 00:30 seconds when the light is directed on the sofa, the room become red because the light that bounce off of the sofa is red.
It is fully dynamic, so as you can see in the attached video below you can even change materials in realtime.
It is useful if you want a realistic flashlight in your character for example, or if you are an artist, you can use it to see a fast result before you bake the light using the lightmass.
Let me know if you want more informations or just tell me what you want to see in the next videos, also leave a feedback if you want to see it on the marketplace.

https://youtube.com/watch?v=rORhCECYHNE

looks good!

I’d venture to say you use a very low resolution rendertarget at the position of the light, blur/average it, and then apply it as a light function to child pointlight component. am I correct?

as critique/feedback I’d say that the indirect lighting seems to lack directionality, i.e. it’s too even across the entire room instead of ‘fading out’ the further away it is from the area that the spotlight is hitting
then I’d be curious to know if the light would leak into the next room. i.e. if your indirect lighting is casting shadows

and finally I’d ask the obvious question: what’s the performance hit?

Looks like a skylight with controls over brightness driven by spotlight angle and colour driven by a trace in the direction of the spotlight to me.

Hi!

Wow you got it! :smiley: Yeah I’m still trying to find a good range of parameters to smooth out the indirect light, I look A LOT at lightmass results to do that.
To answer your question: yeah it supports indirect shadows…but they cost too much, and I’m thinking about removing them; talking about performance, with a fully dynamic spotlight with direct shadows enabled they are pretty good, but when you start using three/four of them, they can cause performance drops, at that point even direct shadows aren’t fine.
In the “Sun Temple” project with a third person character with only 1 spotlight I was around 80 fps inside the editor (i5 3570k 4ghz, GTX 780, 8GB RAM).

Thank you for your feedback :]

That would be pretty limited, because you can use only one skylight per level :slight_smile:

Wow this looks extremely awesome! The Flashlight idea reminds me of Alan Wake :smiley:
Please put it on the marketplace.

Thank you :slight_smile: