Getting the value of the light falling on a surface, for example in lux

The final point I came to on this issue was as follows. I couldn’t progress after that. I don’t know if it’s the right way, but I wanted to share it in case it might be useful to someone.

https://github.com/EpicGames/UnrealEngine/commit/033af80a87b7b664c519be5f0f2d354252c3df2a

line 179

https://github.com/EpicGames/UnrealEngine/blob/1e5926084bbf386041103735ed6c2ab27bc1c1ee/Engine/Shaders/Private/PostProcessVisualizeHDR.usf#L205

It is necessary to find out where the values here come from. If these are found, the formulation here can be used, but I am speaking hypothetically.


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