I was analyzing very clearly how engines, such as Unity, Godot and Unreal, work. I think I decided to think of a way to not use global illumination or lumen for first-person games. In fact, I noticed that you try to simulate white light in the engine. But every computer is already filled with light to turn on the screen (hardware). This seems like biological philosophy, but it is not. I understood that everything is captured through a camera, but there is a principle. There is an environment that the camera captures as a camera, not as an eye. The Journey of Light: When light enters the eye, it passes through several structures until it reaches the retina, where the images are captured. An example of this is when man made a camera. But I am not talking about, for example, the angle of the camera in the engine. For example, if our eyes capture ambient light and there is the issue of adapting to the increase and reduction of the cornea, this option does not exist in the engine cameras. Because it seems that when everyone is developing a game camera, they have stopped thinking about what the eye is like. When you are in the dark in a closed place, your cornea adapts, but there is some light. So how can you differentiate without light from real life for the engine? In the engine, when you put global illumination, what you do is create a synchronized light web. But analyzing it well, in a first-person game where there is a cornea in the camera, I don’t need to have this need for excessive lighting. Why? Simulating the opening and closing of the cornea in the camera will generate less processing in the games. Because this principle is linked to nature and simulates light better in games. But to explain it completely, I would have to change the engine and redo the camera part.
Cameras in Unreal do have “Eye Adaptation” enabled by default. In effect, they are doing exactly what you are describing. The camera will always auto adjust to different levels of light, and you can customize how fast or strong this effect is using camera attributes, or rendering attributes on a Post Process Volume. These settings are under Post Process > Lens > Exposure. Have a look around there and the related documentation to learn more.
As Evan mentioned, you can use eye adaptation to adjust the exposure to simulate this. And games have been doing this for ages. It is no substitute for GI.
Global illumination is a totally separate concept that states that light bounces off of surfaces potentially several times before reaching our eyes (or a camera) and has little or nothing to do with how bright or dark we perceive the environment due to our eyes biology or camera exposure other than the fact that it may not be easily observable in extreme darkness - even though it is still happening. The brighter the light, the more observable its indirect illumination is to environment.
what an essay. nobody has captured human eyesight yet. autoexposure does all of that. just eyeball the graphics. literally.