Lets make Lightmass EPIC (and understandable)

Hello!

I am one of those who continue to use static lighting.

In my case, I’m working on a VR game where the player is shrunk to a size of 8 cm and explores an entire house as if in an open-world environment.
I will release an update, so I post now.

Here are the results I was able to achieve:









Here my DefaultLightmass.ini :

[DevOptions.IrradianceCache]
RecordRadiusScale=0.8

[DevOptions.StaticShadows]
NumShadowRays=12
NumPenumbraShadowRays=12

[DevOptions.ImportanceTracing]
NumHemisphereSamples=64

[DevOptions.PhotonMapping]
DirectPhotonDensity=1200
DirectIrradiancePhotonDensity=1200
IndirectPhotonPathDensity=5

IndirectPhotonDensity=1200
IndirectIrradiancePhotonDensity=600

NumIrradianceCalculationPhotons=800
IndirectPhotonSearchDistance=400

DirectPhotonSearchDistance=300

World Settings:

StaticLightingLevelScale=0.2
NumIndirectLightingBounces=20
NumSkyLightingBounces=5
IndirectLightingQuality=5
IndirectLightingSmoothness=0.75

Because the player is very small, I use high resolution light maps.

The full scene takes 9 hours to bake with three computers:

  • AMD Ryzen 9 7950X 16-Core Processor
  • AMD Ryzen 7 2700X Eight-Core Processor
  • AMD Threadripper 1950X 32-Core Processor

As you can see the light is far from perfect there is a lot of light leaks between the mehes that I can hardly correct, but overall, I’m quite happy with the result.
This kind of scene uses a lot of indirect light from many sources, which doesn’t render as well with Lumen and uses a lot of resources.
I still believe static lighting is the best option for both optimization and quality when dynamic lighting isn’t necessary.

I find it unfortunate that static lighting is increasingly rejected.
This topic helped me a lot and I hope this post can help and motivate other people.